In my view, the hardest part of the Constitution's original meaning to understand is the 14th Amendment. While we have made great progress in understanding this provision, we unfortunately do not yet have a satisfactory theory of the Clause.
Adequate theories of the original meaning of the 14th Amendment must do several things. Two of the most important are to give effect to the text of the Privileges or Immunities Clause and to explain how the Amendment established an equality requirement that rendered the black codes, which discriminated against former slaves, unconstitutional.
One of the strengths of Kurt's theory is that it gives a straightforward account of the text of the Privileges or Immunities Clause. The Clause provides that "No state shall make or enforce any law which shall abridge the privileges or immunities of citizens of the United States." Under Kurt's view, these "privileges or immunities" refer to the rights enumerated in the U.S. Constitution. This is a very plausible reading of the language. And Kurt provides some evidence in favor of it from the historical record.
Another attractive feature of this reading is that it provides a clear indication of what these rights are. Other interpretations of the Clause have struggled to define precisely what rights are protected.
The problem for this view concerns the second requirement of an adequate theory of the 14th Amendment: that it explain how the black codes were unconstitutional (and more generally how the Amendment imposes an equality requirement). Presumably, Kurt believes that the Equal Protection Clause imposes that equality requirement. But there are serious problems with this interpretation as a matter of the original meaning.
As John Harrison, Chris Green (and many other authors) have argued, the Equal Protection Clause does not really do what modern interpretations say it does. The text of the Clause – which provides that no state "deny to any person within its jurisdiction the equal protection of the laws – does not prohibit states from passing "unequal laws." Instead, it identifies what was at the time a well known legal category – the protection of the laws – and requires that it be equal. The protection of the laws referred largely to remedial matters – the laws and institutions that protected people's rights (but for the most part not the rights themselves). Thus, the Clause prohibited states from not protecting the rights of the former slaves (and other groups). Moreover, there was a good reason for imposing this requirement: it specifically prohibiting southern sheriffs from looking the other way when militant groups lynched blacks.
But under this reading, the Equal Protection Clause does not require that a significant portion of substantive rights be equal. It is largely up to the states to decide what rights should be protected. And therefore there is no prohibition against state laws discriminating against the rights of blacks.
If the Equal Protection Clause had this meaning, then this is a serious problem for Kurt's theory. Since the Privileges or Immunities Clause under his view does not protect the equality rights of citizens, Kurt appears to be left with no provision that imposes that equality requirement. And that would constitute a serious defect in an interpretation of the 14th Amendment.
Kurt has emphasized that the Comity Clause is included within the Privileges or Immunities of citizens of the United States, but that Clause protects against discrimination against out of state citizens, not against racial discrimination. Ryan Williams has argued that the 14th Amendment Due Process Clause imposes an equality requirement, but Ryan's argument has been disputed by Chapman and McConnell, and has not been generally accepted.
Ultimately, Kurt's theory requires that there be some basis for the equality requirement of the 14th Amendment. While perhaps Kurt will find historical support for such a requirement in the future, until he does his interpretation of the 14th Amendment suffers from this serious defect.


The wait is over! We are very excited to announce the finalists in the 2018 NEIS Awards. Judging is underway to determine the winner for each category, to be announced at the 2018 NEIS Awards Dinner to be held at Crowne Plaza Coogee Beach, NSW on Monday 8th October 2018. Follow us on Facebook for updates.
Congratulations to the following finalists, selected from over 30 nominations received from NNA members.
To be eligible for this award, businesses must have been in operation for less than two years, from the date the nomination is received.
Nominating NNA Member: Sarina Russo.
Emily Bitkow saw it was the right time for the reinvention of the 80s fashion staple, the bumbag. Her unique update, the VIVRA, features the use of heavy-duty magnets to attach a pouch to the wearer's clothes, instead of traditional belts or straps. The brand has experienced rapid expansion, assisted by skillful use of social media. VIVRA pouches are sold Internationally through selected stockists, and from their online store.
Nominating NNA Member: Business Foundations.
A passion for educating people on the need to reduce plastic waste inspired Mary Jane Gibbs to create Waxiwraps; a premium quality, reusable, washable, eco-friendly beeswax fabric food wrap. This appealing alternative to single-use plastic has created employment for another three people and now sees Waxiwraps available in over 30 stockists.
Gemma Holmes knew the limited availability of products free from harsh chemicals and animal testing. These often looked for and seldom found features are a defining strength of Gemma Vendetta Cosmetics. The range is chemically safe, 100% certified vegan and cruelty-free. These mineral cosmetic products are now found in over 40 stockists.
Business: MAJ Total Quality Improvement Services.
Nominating NNA Member: Gramets – Box Hill Institute.
MAJ Total Quality Improvement Services is the new business of Anastasia Jacobs. Consulting to export manufacturers, retailers and market stalls within the food industry, MAJ Total Quality Improvement Services clients achieve high-quality assurance standards through Anastasia's diligent work and clear communication. The business consults to many clients, from small retailers to large manufacturers.
This award recognises that NEIS often changes lives forever. To be eligible for this award, the business must be able to show that undertaking the NEIS program has turned their life around – be it financially, mentally and/or emotionally, have completed their year of NEIS assistance and be off Centrelink benefits.
Luke Davenport's regional location made it difficult for him to access support to improve his opportunities. After unsuccessfully applying for jobs in his industry, Luke signed up as a NEIS eLearning participant, then started his own business, Acid Interactive. His passion is game development; from design, art and sound, to visual effects. Luke is conscious to remain flexible and open, to help clients with projects as varied as producing artwork, or solving tricky coding for prototypes.
Nominating NNA Member: Konekt Employment.
Daniel Hastings overcame severe anxiety to start Coast Garden Solutions. A lifelong passion for gardening, along with NEIS training and mentoring, has given Daniel the confidence to build his garden design and maintenance business. From planning and design through to reinvigorating the overgrown, Daniel's knowledge is displayed through Coast Garden Solutions Facebook and blog posts. Daniel provides work experience for local students and is looking forward to putting on his first staff member.
Nominating NNA Member: My Pathway.
Elina was unable to secure employment and wanted to be self-sufficient. With the support of NEIS she was able to start Elina's Cleaning Services. From catching the bus to client's houses, to eventually purchasing her own vehicle, Elina's business has gone from strength to strength. She has identified the features clients want in a single person cleaning service and promoted her business to those needs. A healthy pricing structure has been maintained because of the diligent and enthusiastic service she provides.
Nominating NNA Member: Gramets – Kangan Institute.
Danny found it difficult to secure a position in his trade. With three children to support, he commenced NEIS training in order to build the confidence to start his own business. Deluxe Interiors Oz started in a garage, and within 12 months had secured enough regular contracts to move to a factory setting. Attention to detail is the key to Danny's success. Cabinetry designs for residential and commercial projects are custom-cut and edged with precision in-house. The business has now employed a designer and two factory/installation assistants.
To be eligible for this award, the person must be an employee of a NEIS provider and actively involved in the conduct of NEIS.
Derek Bond works with Brace Education and Training to provide the best in NEIS training.
Derek has been known to do a 550 km round trip to mentor one person because he gets so much enjoyment from helping people. His classrooms are invariably 'go to' places for current participants. He is adept at uniting a new group of previously lone participants into a vibrant community that continue to support each other well past the classroom stage of their business.
Natasha Brown works with Training Connections Australia to provide the best in NEIS training.
Natasha focuses on what she describes as individual transformation with her clients. Skills development and confidence are central. Natasha is mindful to adapt the delivery of information to the skills of clients and the stage of the journey they are up to. The range of guest speakers engaged helps to reinforce the program as Natasha motivates, establishes accountability and creates a culture of progress.
NEIS provider: Gramets – Kangan Institute.
Leigh Spiden works with GRAMETS – Kangan Institute to provide the best in NEIS training.
For over 15 years Leigh has been the first point of contact for all enquiries, both by phone or through the door. Leigh has a comprehensive understanding of the NEIS program and of the criteria necessary for intending start-up businesses to present in order to be processed for entry to NEIS. Over 3000 clients have received complete and undivided personal attention. Some clients with challenges or personal issues will find Leigh is always willing to 'hear their story', then gently re-direct them to where they need to focus, to most successfully complete their NEIS training.
For information on FREE small business training with the NEIS program, use the postcode search tool to find your nearest NEIS provider.


An ISO 9001:2008 Certified Company, Bhagwati Steelage Industries is India's leading distributor and supplier of ASTM A554 stainless steel welded mechanical tubes. We are a leading exporter of stainless steel polished tubes supplier as per ASTM A554 standards in grades SS201, SS304L and SS316L.
An ISO 9001:2008 Certified Company, Bhagwati Steelage Industries (Pipe & Tubes Division) is one of the leading stockholder and supplier of ASTM A554 welded stainless steel tubing for mechanical applications where appearance, mechanical properties, or corrosion resistance is needed in a number of standard sizes and grades. Our stock of stainless steel polished/non polished welded tubes primarily consist of the austenitic grades of stainless steel including 201, 202 (4% Ni), 304, 304L, 316, 316L, in annealed and pickled, 2B finish, bright annealed, mill finish and polished conditions.
ASTM A554 polished stainless steel ornamental tubes are widely used for building constructions and architectural applications.
This specification covers welded austenitic and ferritic stainless steel mechanical tubing intended for use in ornamental, structural, exhaust, and other applications where appearance, mechanical properties, or corrosion resistance is needed.
ASTM A554 polished stainless steel pipes are generally used for architectural applications, as the polish on these pipes gives a special appearance. We can offer polished stainless steel pipes in NO.4 finish (400 grit finish), and NO. 6 finish (600 grit finish). ASTM A554 stainless steel pipes pipes can also be offered in 2B finish.
Product reliability and performance has made Bhagwati Steelage Industries a leading exporter and distributor of ASTM A554 stainless steel polished tubes and pipes in India and international markets such as UAE, Bahrain, Indonesia, Malaysia, Mexico, Chile, Brazil, Peru, Nigeria, Kuwait, Jordan, Thailand (Bangkok), Venezuela, Iran, Germany, UK, Canada, Russia, Turkey, Australia, New Zealand, Sri Lanka, Vietnam, South Africa, Kazakhstan, Saudi Arabia.
Our products are supplied to all major Industrial areas and cities in India such as Mumbai, Delhi, Bangalore, Hyderabad, Ahmedabad, Chennai, Kolkata, Surat, Pune, Nagpur, Indore, Thane, Bhopal, Visakhapatnam, Vadodra, Nashik, Faridabad, Rajkot, Aurangabad, Ranchi, Coimbatore, Raipur, Mysore, Bhubaneswar, Salem, Bhilai, Bhiwandi, Bikaner, Mangalore, Kochi (Cochin), Bhavnagar, Tirupur, Ankleshwar, Assam, Siliguri, Jamshedpur, Warangal, Nellore, Agartala and Thoothukudi.
Our high quality steel pipes, good customer service, and in house pipes and tubes processing capabilities have made us one of the emerging suppliers of ASTM A554 stainless steel tubes in the Middle East such as including Bahrain, Cyprus, Egypt, Iran, Iraq, Israel, Jordan, Kuwait, Lebanon, Oman, Palestine, Qatar, Saudi Arabia, Syria, Turkey, United Arab Emirates and Yemen.


Tariq Ramadan, the leading Muslim academic, has resigned his professorship at an American university after authorities refused to give him a visa.
Swiss-born Prof Ramadan is one of the most respected philosophers of religion and conflict resolution; he has argued for a more moderate and modern Islam, and was named by Time magazine as one of the world's top 100 influential thinkers this year.
But in July his American visa was revoked under the Patriot Act, adopted after the terrorist attacks on September 11, prohibiting him from taking up the post at the University of Notre dame in Indiana. They have so far refused to issue a new visa.
Today he announced his resignation of two professorships at the university - professor of Islamic studies in the classics department and professor of religion, conflict, and peace building - and accused the American authorities of attacking academic freedom.
In a written statement Prof Ramadan said: "No matter what decision I have taken today, I am still waiting for the American administration to reveal the results of their investigation so that my name can be cleared of all the untrue and humiliating accusations against me during these last few months. As yet, not a single piece of evidence has been produced to substantiate the claims made against me, which I believe is a classic case of infringement of academic freedom.
He thanked the university and his supporters from around the world, and added: "It is they who are promoting pluralism and democratic debate. The American administration, on the other hand, seems to be unfortunately demonstrating signs of a rapid descent into a closed and worrisome unilaterism."
Prof Ramadan claims he has been called an anti-semite and has been accused of having links to extremist Islamic groups.
The university expressed regret at the news. R Scott Appleby, director of the Joan B Kroc Institute for International Peace Studies, said: "We are disappointed that Professor Ramadan will not be joining our faculty. Faculty and students at Notre Dame and at other US universities were looking forward to engaging him productively on a variety of issues central to our times. Such dialogue, we believe, is an essential requirement to a deeper understanding of the complexity of the Muslim world."
In November, speaking at a debate organised by the Guardian, he argued that the British Muslim community was ahead of any other Muslim community in Europe and has a far more sophisticated understanding of its place in society, but, he added Muslims should, "get rid of the defensive attitude".


text:
Stokes falls cheaply as RR wobble at start
The England batsman was at the receiving end of a perfect delivery from Trent Boult. The ball angled into Stokes from a good length and shaped away with a tad extra bounce.
Team Sportstar
11 April, 2018 20:42 IST
Ben Stokes is dejected after his dismissal against Delhi Daredevils. - AFP
Indian Premier League's costliest player Ben Stokes couldn't make an impact as he was dismissed for just 16 runs in Rajasthan Royals' match against Delhi Daredevils.
The England batsman was at the receiving end of a perfect delivery from Trent Boult. The ball angled into Stokes from a good length and shaped away with a tad extra bounce. The ball took the Stokes' outside edge and Delhi wicketkeeper Rishabh Pant reacted sharply and dived to his left to do the rest. The wicket left Rajasthan tottering at 28/2 in the fifth over.
Stokes was bought at a price of Rs. 12.5 crore in the IPL auctions.
The southpaw has been in the news in the recent past after he was charged with affray following an incident at a nightclub in Bristol last September. He was suspended by the England Cricket Board and missed The Ashes trip to Australia. Stokes had a mixed return to cricket in England's series against New Zealand.
Delhi Daredevils

redpajama_set_name: RedPajamaCommonCrawl


Recently I had the privilege to visit textile designer, Alison Glass', home studio. I've been quilting for a little over two years and find field trips like this very exciting and educational. I'm so glad she invited our guild into her studio. I'll let the images do the walking and talking . . .
School starts tomorrow . . . and I didn't get my summer to-do list done! It's going to be so-o-o hard looking out of the class window watching tourists toting chairs, towels and boards to the beach.
How about some photos of Ming Mamma's secretary cabinet?
Sorry, but they're a little grainy.
"Ming Mamma's" moniker was born out her very young grandchildren's mispronunciation of "Big Momma" – and it stuck. She was the oldest daughter in her family and had a much prettier name, Lola Mae. As a newlywed, Lola proudly polished her 1930s secretary cabinet each week. When it was time, her oldest, Lillian Mae (my awesome Grandmother) kept the secretary in her living room filled with the very odd knick-knacks. As children we were fascinated by the hidden compartments in the hide-away desk. Now, it sits as an honored guest in my living room. It is filled with heirlooms passed down by Lola, Lillian and my mom, Joan.
Lola Mae liked to place vignettes under the Christmas tree on Christmas Eve. For some weird reason, this mechanical rickshaw with a seated geisha girl made (I think) in the 1940s was part of that tradition. Hmmm. This guy doesn't look too happy.
My Grandfather was stationed in Alaska in the early 1940s. Lonely, he sent for his wife, Lillian, my mom (12) and aunt (10). There was one other child, but no school there. (Every kid's dream). A cargo ship carrying their belongings sank on the way home. An ivory bullet pencil carved by Alaskan Eskimos was one saved memento from their years in Alaska.
I keep my other Great-grandmother, Ella Mae's Lusterware salt and pepper cellars with Lola's berry bowl set here. I've never used either. Afraid to.
The sterling match safe belonged to my Great-grandfather, Thomas (Ella's hubby). The photo is of Lillian at her daily pastime: the beach. The other is of her pushing her little cousin taken around 1915.
Lillian had a fascination with anything "royal." LOL.
Hence, the tiny 1950s coronation coach.
but every piece has a story and is priceless to me.


Indirect ELISA kit for the detection of anti-Schmallenberg virus (SBV) antibodies in ruminant serum and plasma from multiple species, including cattle, sheep and goats.
* Each sample is tested in duplicate in a coated well (even columns) and in an adjacent non-coated well (odd columns). Results are calculated with respect to the corrected sample OD value (even well OD – odd well OD).
Kaba et al. Schmallenberg Virus Antibodies Detected in Poland. Transboundary and Emerging Diseases. Rapid Communication. 2012.
Linden A, Desmecht D, Volpe R, Wirtgen M, Pirson J, Paternostre J, et al. Epizootic Spreads of Schmallenberg virus among wild cervids, Belgium, fall 2011. Emerg Infect Dis (Internet). 2012 Dec.


Amsterdam, London - The Ahwaz Human Rights Organization (AHRO) strongly condemns the assassination of Ahwazi-Arab activist, Mr. Ahmad Mola Neisi, an Iranian dissident in front of his home in The Hague, Netherlands, Wednesday evening, November 8, 2017, by unidentified gunmen as reported by Dutch media.
The circumstances of the assassination are still unclear, since no statement has been issued by the police or the Dutch authorities so far. Therefore, AHRO calls for an urgent investigation into the circumstances of the case and the release of the names and the identifies of perpetrators of the assassination of activist Ahmad Neisi, the leader of the Hraketa-e-Elnidal Alrabi Litahrir Alahwaz, and an Iranian exiled dissident group in Europe.
Is the Iranian regime behind this heinous and the cold-blooded assignation, or is it complacent in it anyway? Dutch authorities are obligated to address this issue promptly.


text:
Hazel Log Cabin Cottage See more	 Beacon Fell View See more
Corner Cottage See more	 Spring Wood Lodges See more
Hoseasons Vale of York Holiday Parks See more
< Area Guides
< Kettlewell
Situated in the very heart of the Yorkshire Dales, Kettlewell is a truly picturesque village, with its limestone cottages and picture perfect scenery. Surrounded by the most stunning countryside, the village is ideal as a base for exploring the area and is popular with walkers and cyclists. The village itself is a tranquil haven which offers a great choice of accommodation, from hotels and guest houses to self catering cottages.
Visitors are well catered for with a general store, post office, clothing shop, gift shop and two traditional pubs. Ewedale Model Village is a fascinating, interactive miniature display situated below the Kettlewell Village Store and opens on weekends and during school holidays. Local artists display...
their work in the village studio gallery and there is also a framing service for that special purchase. There are two tea rooms, one of which becomes a bistro in the evenings, and the friendly local pubs offer a welcome place to sit, relax and unwind.
Tourist Listings
Sort by : - Default - Title: A-Z Title: Z-A Town: A-Z Town: Z-A Region: A-Z Region: Z-A
Yorkshire Dales Wildlife
Skipton, South Dales
The Yorkshire Dales is a stunning area of natural countryside which houses a great number of nature reserves. Home to a wide variety of animals, birds, flora and fauna including many rare and...
Malham National Park Centre
Malham, Skipton, South Dales
Malham National Park Centre is a wonderful place to visit and learn the fascinating facts about Malham Cove and the surrounding area. Maps and guides are available for walkers and tourists, and the...
Airedale is located at the western fringe of the Yorkshire Dales National Park in North Yorkshire. Airedale and Skipton are often described as the gateway to the Yorkshire Dales and they both are...
Yorkshire Dales Cycling
The diverse landscape of the Yorkshire Dales, with all its hills and dales, bridleways and tracks is suitable for cyclists of all ages and experience. The quiet lanes are perfect for families and the...
Yorkshire Dales National Park Visitor Centres
The vast area covered by the National Parks stretches throughout the wonderful Yorkshire Dales. To ensure that visitors can take full advantage of all there is to offer, the National Park Visitor...
Peregrine Falcons at Malham Cove
Peregrine Falcons can be seen in their natural habitat at Malham Cove. These magnificent birds of prey have made their home amongst the rock cliffs of the cove and are protected during the breeding...
Malhamdale
Malhamdale in the Yorkshire Dales is the name given to the area surrounding the Upper region of the valley of the River Aire, which is well known for its magnificent limestone scenery.
Parcevall Hall Garden
Parcevall Hall Gardens form part of the Yorkshire Dales National Park and command a stunning location on the hills above Wharfedale. The exquisitely planted gardens and woodland are perfectly kept...
Skipton Little Theatre
Skipton Little Theatre has been an institution since the 1960's and is full of character and atmosphere. Encouraging amateur actors and supporting the Skipton Players, this tiny theatre provides a...
Craven Court Shopping Centre
Craven Court offers the ultimate shopping experience in a beautiful listed building, which is now an all weather arcade. A great selection of shops, an adjacent outdoor market and plenty of parking...
Land Rover Experience
The Land Rover Experience provides the opportunity to get to know the vehicle under expert supervision, have some great fun with the off roading and brush up your driving skills. Courses are...
Kilnsey Trekking and Riding Centre
Kilnsey Trekking and Riding Centre is family owned and offers riding tuition for all ages and abilities. Expert guidance on stable management and equestrian care are also on offer. Childrens...
Twin Locks Garden Centre
Gargrave, Skipton, South Dales
Twin Locks garden Centre in Skipton is a year round friendly business which stocks all your gardening needs. Top quality plants, trees, equipment and accessories are available to keep your garden...
Wharfedale is one of the Yorkshire Dales longest and most beautiful dales, and is located in the south of the National Park, and is home to some of the prettiest towns in England. The stunning Bolton...
The Inn Way to the Yorkshire Dales
The Inn Way to the Yorkshire Dales offers an alternative route through the stunning countryside, especially appealing to real ale lovers. The route takes walkers through towns and villages with...
Craven Sailing Club
Craven Sailing Club in Skipton is based at Embsay Reservoir near Skipton. The 27 acres of the reservoir provides a great environment for learning to sail and for demanding but enjoyable racing.
Kilnsey Park fly fishery is set in delightful countryside and offers two well stocked trout lakes. The fishery holds several events throughout the year and visitors can hire rods from the on site...
Buckden - Upper Wharfedale
Buckden is a bustling and thriving Parish to the north of Wharfedale, and consisting of stunning fields and meadows and hemmed by traditional dry stone walls. The area is dotted with farm houses, and...
Grassington National Park Centre
A visit to Grassington National Park Centre is a great way to spend a day and learn about the fascinating history of farming and the local area. There is an abundance of information and lots of...
Whether you enjoy sketching, painting or model making, The Art Shop in Skipton has everything you could possibly need for your chosen hobby. Come along and have a browse, plenty of free advice...
Royal Oak Furniture
The Yorkshire Dales is full of surprises; it's not just magnificent walks and scenery, its home to the Royal Oak Furniture Company in the beautiful village of Wharfedale.
CluesGo Treasure Hunts
CluesGo brings the age old excitement of a treasure hunt back into the countryside. And where better than the stunning Yorkshire Dales to explore every hill and dale along the way. You are sure to...
Craven Swimming Pool
Craven Swimming Pool is an ideal place to visit whether you want a gentle swim, some serious exercise or just to socialise with friends. The two pools cater for all ages and abilities and offer...
The Mart Theatre
One of the most unique theatres in the world and the only theatre to share its building with an auction mart! Yes that's right, cows strut their stuff and take centre stage by day, while evening time...
Pennine Boat Trips
Cruise on the Skipton canal and enjoy a family fun day out with Pennine Boat Trips in North Yorkshire. Simply take a trip along the canal and enjoy the tranquility and great Yorkshire scenery,...
Results per page : 10 25 50 100


Many resources were shared at the March 2010 meeting of the Book Arts Guild of Vermont. Links to these resources are listed below, including those that came up during discussion.
A resource booklet was given to everyone who came to the presentation – the pages were bound using a pamphlet stitch. You can download a copy of the booklet by clicking here. The pages are formatted for binding – just fold the two pages in half, nest them, and you're good to go!
Umbrella: An online quarterly by Judith Hoffberg covering the arena of artists' books, art books and other multiple editions, including audio and new media.


When SCCM 2007 was going through beta I put together some flowcharts providing detail into how the new components work. Specifically, flows were built for DCM, SUM, OSD, NAP and Peer DP's. Thought these might be useful to the community as well so posting them here.
Please note that these flows are built based on early beta builds of SCCM 2007 and I'm sure there are errors or items that have changed in the flows.
I have no plans to update the flows to reflect changes that might exist in the current release of the product. Please also note that these flows are provided AS IS and are not supported in any way by Microsoft.
4. Select properties on the new SCCM207flows virtual directory. Select the documents tab and select edit. Type in 'flowchartmain.htm' and select OK. Move flowchartmain.htm to the top of the default content page list and select OK.
Note: The web page has been tested with IIS 6 but not IIS 7. Also note that the flowchart is designed to run locally - not remote web browser. Folks comfortable editing web pages should be able to change the 'localhost' reference that is used on the main page to a specific servername for your specific environment. The main page is the only location that would need to be modified.
I'm in the midst of writing a project plan for the design of an SCCM infra and just found your wonderful flow diagrams.
I'm not able to follow the flowchart link, as the URL it is not reachable. Please post the new URL.
Just checked the link and it is fine.
Can you please share the policy flow in Application Mgmt & Patch Process. what are the policies generated for the deployments or any and it's reach to client.


text:
\section{Introduction: the Long Road from 2001 to 2016}

\input{s01intro}

\section{Epistemology}
\input{s02background}

\section{Decentralization and Privacy}
\input{s030Questions}

\section{Future Research Lines}
\input{s04directions}

\section{Conclusions: Towards Full Decentralization}
\input{s05conclusions}

\vspace{2mm}
\noindent \textbf{Acknowledgements.} The authors would like to thank the reviewers for insightful comments that helped improving the paper, in particular Prateek Mittal for acting as shepherd. This work is supported by the EU H2020 project NEXTLEAP (GA 688722).

\bibliographystyle{abbrv}

\subsection{How Is Decentralization Achieved?}
\input{s031type}

\subsection{The Advantages of Decentralization}
\input{s032gain}

\subsection{How Does Decentralization Support Privacy?}
\input{s033privacy}

\subsection{The Disadvantages of Decentralization}
\input{s034lose}

\subsection{What Is Still Centralized in Decentralized Designs?}
\input{s035assumptions}

\subsection{Systematization of Existing Designs}
\label{sec:table}

\input{s036table}
\AtBeginShipout{
\ifnum\thepage=1
\pdfpageattr{/Rotate 90}
\fi
}

Table \ref{table:systemsTable} presents a systematic analysis of decentralized designs, clustered based on their principal goal. The columns infrastructure, network topology, authority relations, privacy properties, follow closely the definitions of the previous subsections. We applied some level of simplification to complex systems with multiple components or multiple use-cases. The systematization focuses on parts of the system relevant for its main use-case as used in prototype or deployment.

\vspace{2mm}
\para{Insights}.
\begin{itemize}
   \item \textit{Many systems that provide good coverage of privacy properties and decentralization (usually via DHTs) have not been widely deployed}
   \item \textit{Widely deployed systems either are user-independent federated systems or user-based DHT-based systems, both without advanced privacy properties.}
   \item \textit{Hybrid and stratified systems such as Tor provide provide advanced privacy properties at the cost of centralized assumptions.}
   \item \textit{The space of ad-hoc, mesh, and covert designs is under-explored.}
\end{itemize}

\subsubsection{Infrastructure}
A first key choice concerns the distribution of tasks needed for maintaining a service within the system. The provisioning of infrastructure impacts the design in terms of trust and message routing.

\vspace{2mm}
\para{User-based Infrastructure}. Some decentralized system consist solely of nodes that are users and there is no additional infrastructure. They rely solely on users to collectively contribute resources (bandwidth, storage) in order to provide a service. The advantage of this design is that by nature it does not require a third-party centralized authority. This user-based design can support services such as hosting of encrypted data, e.g. in Freenet~\cite{ClarkeSWH00} and Cachet~\cite{NilizadehJMBK12}.
A disadvantage is that user-based infrastructure may lead to poor performance due to evolving into sparsely connected topologies, and to ``churn'' caused by peers constantly joining and leaving the network.

\vspace{2mm}
\para{User-independent Infrastructure}. Here, the functions of the decentralized system are realized by nodes that are not users. A set of third-parties that are not necessarily trusted may provide all or part of the functionality to users. This design pattern underlies classic open federated protocols such as SMTP~\cite{smtp} and XMPP~\cite{xmpp} based on a client-server model. The advantages of user-independent infrastructure include increased availability of the service, a reduced attack surface, and immunity to user churn. Servers do not necessarily threaten user privacy. The Eternity Service~\cite{Anderson96}, as realized in systems like Tahoe-LAFS~\cite{SelimiF14}, combined encryption with the use of several servers controlled by different non-collaborating authorities for the private storage and replication of files. Other examples of systems that rely on user-independent infrastructure include DP5~\cite{BorisovDG15} and Riposte~\cite{Corrigan-GibbsB15} in terms of Private Information Retrieval~\cite{ChorKGS98} or anonymous communication systems like mix networks~\cite{Chaum81} or DC-nets~\cite{Chaum88}.

\vspace{2mm}
\para{Hybrid Systems}. Functions may be shared between users and nodes run by third-parties. An example is Tor, where relays are mainly run by volunteers but Directory Authorities are operated by a closed `known' group of servers.
In terms of privacy and security, new elements such as distributed ledgers decentralize traditionally centralized cryptographic protocols in these hybrid systems. For example, computations can be locally and securely recorded to the blockchain with the support of multi-party computation protocols~\cite{ZyskindNP15}, even without a trusted third party~\cite{AndrychowiczDMM14,ZyskindNP15}, or using a small number of stable entities to ensure reliability and low-latency, as in the Sharemind MPC system~\cite{bogdanov2008sharemind}.

\subsubsection{Network Topology}
\label{topology}
When considering a decentralized system, there are two distinct topologies. The first, \textit{network topology} describes the connections between nodes used to route traffic; and the second, \textit{authority topology} describes the power relations between the nodes. Thus, the network routing structure does not necessarily have to mirror how authority is decentralized in a system, although it often does. That can greatly affect the security and privacy properties of the system~\cite{DiazMT10}.
It must be noted that components of traditional network routing is done in a hierarchical manner, including spanning tree protocols such as in BGP~\cite{rekhter2005border} in the current Internet as well as `next generation' designs like SCION~\cite{zhang2011scion}.

\vspace{2mm}
\para{Mesh}. Mesh topologies are unstructured. Nodes can route messages to every other node they are connected with. One advantage is that mesh networks function in settings with no stable connections to other nodes to guarantee service in the presence of massive churn and changing connectivity, such as in mobile ad-hoc networking and file sharing in early versions of Gnutella~\cite{Gnutella}. A particularly popular communication means in mesh topologies~\cite{nakamoto2008bitcoin} are \textit{gossip protocols}. In gossiping, as opposed to flooding, a random subset of the nodes in the network are chosen to receive the messages. These nodes then continue to broadcast the message via another independently selected random subset of the network to relay messages. The reliability of message delivery under load is questionable and information propagation experiences delays. Historically mesh networking does not preserve user privacy of their users, but recent secure messaging systems such as Briar~\cite{briar} use this topology to remain functional during Internet blackouts.

\vspace{2mm}
\para{Distributed Hash Tables} (DHT). DHTs are network topologies where each node maintains a small routing table of its neighbours, and messages are passed greedily to known nodes that are `closer' to the intended recipient. Although efficient and decentralized, DHTs do not by themselves provide strong security, privacy and anonymity properties. While decentralized, DHTs are not secure and privacy-preserving by default: Tran et al.~\cite{TranHK09} show that low latency anonymity systems based on DHTs such as Salsa~\cite{NambiarW06} are vulnerable to having large amounts of traffic captured by adversaries controlling a fraction of the relays. DHT nodes may, however, be grouped into byzantine quorums to defeat adversaries that control a minority of nodes~\cite{young2010practical}.

\vspace{2mm}
\para{Super-nodes}. Super-nodes are nodes that are endowed with more, and contribute more, resources to the system. This may be in terms of computation power, storage, or network connectivity, stability and up time. In terms of routing, such super-nodes may be used to mediate operations requiring higher network throughput. They can be arranged in structured topologies, designed to leverage them; or they may emerge naturally in unstructured topologies, as a result of some nodes committing more resources. Most P2P systems such as BitTorrent eventually rely on super-nodes~\cite{DeckerEW13}. These super-nodes have serious implications on availability and integrity, as they may become targets for attack, and privacy, as they mediate, and are in a privileged position to observe, a larger fraction of activities.

\vspace{2mm}
\para{Stratified}. Some of the more complex decentralized systems use a stratified design where nodes have specialized roles in terms of routing, or other functions. A paradigmatic example is the Tor network. Tor users autonomously form circuits from an open-ended set of Tor relays, in layers of entry guards, middle nodes and exit nodes. A high-integrity global list of these relays is maintained through consensus by a closed group of specialized Directory Authorities. Simultaneously, Tor hidden services are resolved through a Hidden Service Directory maintained by a simple DHT topology. We note that, on some level, Tor has also evolved to use super-nodes on its topology and the distribution of traffic sent through Tor relays is far from uniform~\cite{JohnsonWJSS13}. Cascades, are a particular case of Stratified topologies in anonymous communications, in which paths are pre-defined. The advantages and disadvantages of such choice as opposed to free routes has been discussed in~\cite{DiazDGPS04}.

\subsubsection{Authority} \label{sssec:authority}
We now consider the relation among nodes in terms of authority and describe mechanisms to mitigate the potentially effects of power disparity that could potentially harm the security and privacy of users.

\vspace{2mm}
\para{Ad-hoc: Nodes Interact Directly}. In ad-hoc there is no relationship of authority among nodes. Nodes directly interact with each other without the participation of other nodes, and they do so for the benefit of the involved parties only. In terms of routing, ad-hoc requires a mesh topology where nodes do not carry traffic for other nodes. However, note that mesh topologies do not always have a ad-hoc (lack of) authority relations, such as routing based on gossip. An example of this type of system would be point-to-point communication in Briar \cite{briar}.
For purposes of privacy, direct interaction bypasses possibly compromised nodes, but not network adversaries. As for confidentiality, communications can be encrypted between the two nodes, and can be extended to group communication using group key agreement protocols~\cite{SchmidtSCB14}.

\vspace{2mm}
\para{P2P: Nodes Assist Other Nodes}. P2P designs have no central authority. Unlike ad-hoc interaction, nodes provide services and resources to other nodes, such as routing messages or storing blocks of data. Nodes have equal authority and so each node may equally compel any other node, although services and resources are usually provided according to their capacity. In other words, P2P systems self-organize and all nodes are responsible for carrying out operations for all other nodes, rather than having any pre-configured special position of authority. Since nodes are not motivated by authority to help each other, mechanisms should instead be in place to provide `incentives' for collaborative behaviour.

There are clear advantages for the security and privacy properties in P2P systems. Information about peers is not centralized and interaction typically remains local to a few nodes, so it is difficult for an adversary to obtain a global view of the system. Yet, relying on peers for functionality poses an additional threat to privacy, since requests may be served by adversarial nodes. These nodes can passively collect information on other nodes or they may actively disrupt the integrity of operations by forging messages or replay attacks that are hard to detect. Furthermore, since P2P systems are usually open, without any admissions control, adversaries may purposely inject a large number of Sybil nodes, to increase their chances of a successful attack~\cite{Douceur02}. P2P systems are not a silver bullet for decentralization: there is no clear and definite solution to Sybil attacks in P2P networks, although such an attack can be mitigated using reputation~\cite{DamianiVPSV02} or trust~\cite{JohnsonSDM11}.

\vspace{2mm}
\para{Social-based: Nodes Assist Friends}. These designs take advantage of pre-existing decentralized relationships, such as ``friendship''.
In terms of applicability of security mechanisms this approach maintains most advantages of a P2P system. It is less vulnerable to Sybil attacks as adversarial nodes can be excluded from participating in the network or may be easier to detect~\cite{DanezisM09}, as it is harder to infiltrate a social network than a network. The downside is that, without cover traffic, a global passive adversary can discover the underlying social graph by monitoring network communications and violate privacy properties such as unobservability and unlinkability. This in turn may lead to user deanonymization~\cite{NarayananS09}, and techniques such as perturbation of the underlying graph may not be robust enough to prevent this~\cite{mittal2012preserving}.

A number of systems implement social-based communication to resist Sybil attacks. For instance Drac~\cite{DanezisDTL10} and Pisces~\cite{MittalWB13} use social-networks to support routing of messages. X-Vine~\cite{MittalCB12} is a mechanism that, applied to distributed hash tables, helps resisting denial of service via Sybil attacks at the cost of higher latency. Tribler~\cite{PouwelseGWBYIERSS06} uses social-based trust relations to improve performance that exploits similarity to improve performance, content discovery, and downloading in file sharing; or Nasir et al.'s socially-aware DHT~\cite{NasirGK15}, which reduce latency and improve the reliability of the communication.

\vspace{2mm}
\para{Federated: Providers Assist Users}. In federated designs, users are associated to \textit{provider} nodes, which they trust and that act as authorities. Each provider is responsible only for its own users but collaborates with other providers in order to provide a service. No single provider has authority over other providers, and thus there is a ``federation'' of providers. Federated authorities typically use user-independent infrastructure and act as a super-node in terms of routing. This combination of design choices leads typically to high availability as long as the provider is accessible and not compromised, but the provider is a central point of attack to violate security properties and the provider itself can violate the privacy of nodes.
The primary weakness of federated systems is the assumption that federated service providers largely act honestly. Some techniques can relax strong trust assumptions in the provider. End-to-end encryption can maintain confidentiality~\cite{sparrow2016leap} using providers. Computation can be obscured using secret sharing~\cite{RogawayB07} or differential privacy-based solutions~\cite{AlhadidiMFD12}.

\vspace{2mm}
\para{Accountability: Transparency Assists Users}. \label{sssec:type-accountability} Transparency can be used to make an authority accountable in order to establish trust. It promotes integrity of operations by monitoring the correct behavior of nodes, e.g. a transparent log of a provider's operations in a federated system audited by users or other providers acting in lieu of their associated users. The nature of this auditor's authority is very different from the aforementioned previous types of authority relations and critically relies on the non-collusion of the auditor and the audited authority, e.g., Bitcoin consensus over its blockchain using proof-of-work.
Other alternatives, such as Certificate Transparency~\cite{laurie2014certificate}, rely on a set of services and auditors to keep track of X.509 certificates and quickly detect potentially rogue or hacked certificate authorities. Similarly, electronic election protocols~\cite{gritzalis2012secure} achieve robustness through proofs of correct shuffling of votes, e.g., Helios~\cite{Adida08}. Yet na{\"i}ve designs of audit logs may violate the privacy of decentralized nodes by learning too much information.

While decentralized accountability can have clear advantages regarding integrity, there are difficulties in maintaining privacy in any distributed log. This disadvantage can nevertheless be reduced as shown by Zerocash~\cite{Ben-SassonCG0MTV14}, which uses zero-knowledge proofs in order to maintain unlinkability in auditing relationships; or CONIKS~\cite{MelaraBBFF15}, that shows that auditing the consistency of a name-key binding through time enables verification of user public keys by the end users collectively and by other providers, while concealing the identities and the number of users at each provider using Verified Random Functions.

\vspace{2mm}
\para{Insights}.
\begin{itemize}
    \item \textit{Decentralization encompasses a large space of designs from decentralized ad-hoc mesh to federated super-node networks, not just peer-to-peer. These offer a variety of privacy and systems (e.g., availability, or reliability) properties. Developer instincts may often be incorrect in terms of their trade off.}
    \item \textit{Despite being separate parts of the design, the network topology in decentralized systems often mirrors the authorities' trust relationships. However, a strict mapping between authority, infrastructure and networking topology is not necessary, and may come at the cost of harming privacy or availability.}
    \item \textit{Centralization in terms of federated and super-nodes leads to better availability and system performance. However, it introduces single points of failure that impact availability and privacy. P2P models are by design more resilient to unstable routing and compromises, but entail higher engineering complexity.}
    \item \textit{All networking topologies suffer under node churn, and pure P2P topologies must effectively address this effectively to be applicable at all.}
    \item \textit{Decentralization does not imply the absence of any infrastructure. However, the infrastructure itself needs to be decentralized by being provided by a plurality of authorities. Such infrastructure may enhance performance by offering super-nodes or dedicated high-availability operations.}
    \item \textit{De-facto super nodes may emerge naturally in decentralized designs, as a result of different node capabilities, and efficiency in centralizing certain operations. If this occurs outside the context of careful design, those super nodes become a single point of failure, and may lead to de facto re-centralization.}
    \item \textit{Lack of relationships of authority imply that nodes must be willing to provide services to each other on a different basis. Designers of decentralized systems must carefully engineer such incentives, to ensure that natural (non adversarial) selfishness does not lead to dysfunction. Monetary incentives, reputation, and reciprocity can be the basis of such incentives -- but off the shelf such mechanisms are often central points of failure.}
\end{itemize}

\subsubsection{Flexible Trust Models}
An intrinsic advantage of decentralized architectures relates to the existence of multiple independent authorities. These create a distributed trusted computing base that ensures that a subset of rogue nodes, at least up to a certain threshold, cannot compromise the overall security properties of the whole system.

\vspace{2mm}
\para{Distributed Trust}. Decentralized systems leverage multiple independent authorities into a security assumption: for example, all forms of threshold cryptography~\cite{Shamir79} assure that if some fraction of participants are honest, some security property can be guaranteed. This principle can also be applied to secure multi-party computation, distributed key generation, public randomness and threshold-based decryption, and signing.
One such privacy system is Vanish~\cite{GeambasuKLL09} that guarantees deletion after a pre-set expiry date. It illustrates how a multi-authority system implements properties otherwise impossible, or implausible, to when implemented by a single entity. However, the system was in practice defeated by a Sybil attack that the security properties of its DHT did not take into account~\cite{WolchokHHFHRWW10}.
Reliance on multiple authorities to regain a degree of privacy has also been proposed for commercial cloud storage in case some providers are dishonest~\cite{StefanovS13}.

\vspace{2mm}
\para{No Natural Central Authority}. In some settings there exists no central authority and thus a decentralized architecture is a natural choice. This setting has been traditionally studied in the contexts of decentralized access control, as in TAOS~\cite{WobberABL93} and SDSI~\cite{Ellison96}, and `trust management', such as Keynote~\cite{BlazeFK98}. In such systems a set of distributed principals make claims about users and each other, and those claims need to be assembled and used to resolve access control decisions. Bauer et al.~\cite{BauerGR05} show that the task of resolving access control decisions in a decentralized setting is faster than doing so centrally.

\vspace{2mm}
\para{Leveraging Existing Trust Networks}. In some cases a decentralized infrastructure embeds or expresses a pre-existing set of trust relationships that a system may reuse to support security properties.
Systems may use the underlying social trust structure to build overlay privacy-friendly social network services, as surveyed by Paul et al.~\cite{PaulFS14}. As an example, the Frientegrity system~\cite{FeldmanBFF12} provides a social network platform using untrusted providers seeing only encrypted data, where users can exchange information with `friends' protected by cryptographic access control. This use of encryption to defend against the providers themselves is not the case for systems like Diaspora~\cite{bielenberg2012growth}, an open-source project that takes a different approach: users connect to a provider they trust -- that gains full visibility of their activity -- and delegate the access control on the content they share with their social circles to that provider.

\subsubsection{Distributed Allocation of Resources Assists with Ease of Deployment}

A central premise of P2P networks is that nodes contribute spare resources, and doing away with a central authority that is forced to bear the full costs (such as Google's server costs). This reduces costs and helps ease deployment by spreading these demands amongst multiple parties. Costs are lowered as spare capacity in the existing infrastructure is used, e.g., underutilized resources given by users such as the early SETI$@$home project~\cite{anderson2002seti} and the use of users' storage in Freenet~\cite{ClarkeSWH00}.

In terms of availability, decentralized architectures exhibit fewer correlated failures by virtue of being distributed. As an example the Cachet system~\cite{NilizadehJMBK12} uses a pool of untrusted peers as a storage back end of a decentralized Online Social Network.

\subsubsection{Resilience Against Formidable Adversaries}
\para{Location Diversity}. Decentralization provides properties that are inherently difficult to centralize, such as the network location diversity needed for Tor bridges~\cite{dingledine2006design} to bypass censorship both on the network and legal levels. A number of designs take advantage of this, like Publius~\cite{WaldmanRC00}, in order to resist censorship, although censorship resistance itself is a separate field with many centralized, as well as decentralized, solutions.

\vspace{2mm}
\para{Survivability}. Decentralized architectures can be designed to survive \textit{catastrophic} attempts to take them down or inflict crippling damage, in a way that centralized systems cannot resist~\cite{WylieBSGKK00}. This property has been used to build highly robust botnets using a peer-to-peer architecture~\cite{RossowAWSPDB13}. Although these bot-nets are decentralized on the technical level, they of course maintain central but covert command and control (C\&C). Those botnets have demonstrably been harder to take down using conventional techniques, but are also vulnerable to new threats that result from their decentralization, such as poisoning and enumeration of nodes. A further discussion of wider `Darknet' survivability is provided by Zhou et al.~\cite{li2013finding}.

\vspace{2mm}
\para{Separation of Development from Operations}. Decentralized architectures clearly separate the authorities that provide public code -- and that have no access to operational data and secrets -- and those that run the code. Users and nodes, deploying software, can audit any such open source code for integrity, and chose whether to deploy it. The core development team maintains the code, that is publicly visible and auditable, but upgrading is up to independent relay operators. This model is followed by both Tor and Bitcoin. As a result, attempts to coerce the Tor development team can only have an indirect and possibly highly visible effect -- rendering such attempts less effective. Similarly in Ethereum, the exploitation of a vulnerability in the DAO smart-contract, led to the core developers proposing a ``hard fork'', and this fork was voluntarily adopted by the majority of the Ethereum mining node operators.

\vspace{2mm}
\para{Publicly Verifiable Integrity.} Due to the availability of multiple independent authorities, decentralized systems can implement accountability mechanisms to publicly verify integrity. Adversaries are disincentivised to compromise nodes, by ensuring attacks have an observable effect so that cheating can ideally be discovered before it has a negative effect. Verifiable logs can be used to help enable privacy as ensuring that actions are transparent enables users to know what happened with their data, as when Pulls et al.~\cite{PullsPW13} use decentralization to support transparent audits of personal data accesses. Auditability is also a key feature of secure electronic election systems such as the Helios system~\cite{Adida08}. Such systems rely on the existence of multiple authorities in a number of ways in e-voting: threshold cryptography is used for parameter and ballot generation, with privacy enforced via threshold decryption.

\vspace{2mm}
\para{Insights}.
\begin{itemize}
\item \textit{Real-world relationships of trust and authority are personal, complex and localized, and rarely hierarchical or all-or-nothing. Decentralized systems offer flexible trust models that can leverage those relationships to support security and privacy properties.}
\item \textit{When it comes to high-availability and survivability against powerful adversaries -- particularly with legal authority -- decentralized designs are not just best, but sometimes the only available option. Designs that allow operations to continue despite some authorities being adversarial or not available, are necessary to support these properties.}
\item \textit{Decentralization's fundamental advantage in terms of security stems from an attacker having to compromise a set of independent authorities in order to disrupt or weaken the security properties of a system. Decentralized systems that do not offer this property may be more fragile than centralized equivalents.}
\item \textit{Decentralized designs decouple development from operations and have a multistakeholder governance model, where node operators influence the entire system based on the software configuration they choose to deploy.}
\item \textit{Decentralized systems can leverage public accountability to detect and exclude compromised or misbehaving authorities. Such accountability architectures may be used instead of more complex or expensive prevention techniques, but need to ensure that auditing will be effective and eventually acted upon.}
\item \textit{Leveraging spare resources of nodes allows decentralized system to scale, and ease deployment. However, this by itself opens the door to high-churn and cannot be a substitute for robust incentives to participate as the system scales or nodes are asked to take on real costs.}
\end{itemize}

\subsubsection{Increased Attack Surface} Decentralizing systems across different nodes inherently augments the number of points (attack vectors) that an adversary could use to launch an attack or to observe the users' traffic.

\vspace{2mm}
\para{Internal Adversaries}. In centralized systems, system components can be monitored and evaluated by a trusted entity to detect malicious insiders. In a decentralized system it is easier to insert a malicious node undetected. A number of such attacks have been documented against decentralized systems: the predecessor attack~\cite{WrightALS02,WrightALS04} uncovers communication partners in many anonymous communication schemes~\cite{Chaum88,DingledineMS04,ReiterR98,SyversonGR97}, or the Sybil attack which can be used to bias reputation scores~\cite{Douceur02} or corrupt the information exchanged in collaborative decentralized systems~\cite{JanakiramanWZ03}. Furthermore, when messages are relayed through other nodes, e.g., to gain anonymity, their content is exposed to potential adversaries, as in Crowds~\cite{ReiterR98} for Web transactions or in Yacy~\cite{yacy} for searching information.

\vspace{2mm}
\para{Traffic Analysis}. Decentralization inherently implies that information will traverse a network. Even in the presence of encryption, metadata is available to external adversaries. For instance, in anonymous communications networks it has been repeatedly shown that both passive local~\cite{MittalB08} or (partially) global~\cite{JohnsonWJSS13,MurdochZ07}, as well as active adversaries~\cite{WangCJ05}, can reduce or break anonymity by looking at traffic patterns.

\vspace{2mm}
\para{Inconsistent Views}. Decentralization typically implies that nodes have a partial, thus non-consistent, view of the network which can have an impact on integrity. These non-consistent views allow adversaries to ``cheat'' without being detected. For instance, in Bitcoin adversaries can perform double spending by forcing non-consistency through fast operations~\cite{KarameAC12}, or eclipse attacks~\cite{HeilmanKZG15} in which the adversary gains control over all connections of a target node thus isolating her from the rest of the network.
Furthermore, the lack of global information results in users not necessarily making the optimal choices with respect to optimizing their privacy, as studied both in the context of anonymous communications~\cite{DingledineM06} and location privacy~\cite{FreudigerMHP09}.

\subsubsection{Cumbersome Management}
An obvious problem of decentralization is that no entity has a global vision of the system, and there is no central authority to direct nodes in making optimal decisions with regard to software updates, routing, or solving consensus.
This makes the availability of a decentralized network more difficult to maintain, a factor significant enough to contribute in the failure of a system, as pointed out by the Mojo Nation developers~\cite{wilcox2002experiences}.
It is very common that nodes in a decentralized system have hugely varying capabilities (bandwidth, computation power, etc.)~\cite{FeldottoSG14,WachsOG14}, making super-nodes attractive targets~\cite{MitraPGG07}. Finally, decentralized systems need to overcome the shortcomings of underlying technologies (such as NAT~\cite{LiuP09}), that favor the client-server paradigm over peer-to-peer networking.

\vspace{2mm}
\para{Defense Difficulties}. The lack of central management hinders the establishment of effective protection mechanisms. For instance, the non-consistent view of the network not only enables attacks, but also hampers the use of collaborative approaches to detect incorrect information~\cite{KapadiaT08}. Similarly, it becomes extremely difficult to prevent Sybil attacks, and defenses must either leverage local information, for example defenses based on social networks~\cite{DanezisM09,YuGKX10}, or collaborative approaches that combine information from several nodes~\cite{ParnoPG05}.

\vspace{2mm}
\para{Routing Difficulties}. A straightforward consequence of the lack of centralized control is an increased complexity in routing. Nodes do not have an overview of the network and its capabilities~\cite{SuselbeckSKB11} and consequently cannot globally optimize routing decisions~\cite{ZageN07}, falling back to inefficient flooding or gossiping methods in mesh topologies. This is made harder by highly diverse nodes~\cite{FeldottoSG14}, the existence of churn~\cite{ArtigasL09} and the reliance on possibly malicious nodes~\cite{WangMB10}. Solutions to these problems include using complex routing algorithms to enable secure and private discovery of nodes~\cite{McLachlanTHK09,MittalWB13,MittalB09}, or avoiding the use of a centralized directory via next-generation DHTs.
The lack of centralized routing information in decentralized topologies also impacts performance as it hinders the selection of optimal routes or load balancing. We find two approaches to alleviate this problem: using local estimations to improve performance~\cite{AlSabahBG12,AlSabahBGGMSV11,TangG10}, or providing means for users to make better decisions about routing individually~\cite{SnaderB08}. The latter is known to be prone to attacks~\cite{HerrmannG11,MurdochW08}.

\subsubsection{Lack of Reputation}
Decentralization is also an obstacle to the implementation of accountability and reputation mechanisms.
The negative effect is amplified when privacy and anonymity mechanisms are in place, as it becomes even more difficult to identify misbehaving nodes such as Sybils~\cite{HoffmanZN09}. An effect of this lack of reputation is that nodes have no incentive to behave correctly and can misbehave to obtain advantages within the system (e.g., better performance). This problem has been identified in many settings such as P2P file sharing~\cite{ZhaiCCZLSQTC09}, multicast communication~\cite{YuGS12}, or reputation~\cite{HoffmanZN09}. In particular, the presence of churn, which make nodes short-lived and difficult to track over time, makes the establishment of reputation to guarantee veracity a very challenging problem~\cite{RayaMFH08}, even more if privacy has to be preserved~\cite{SchiffnerPT11}.

\vspace{2mm}
\para{Poor Incentives}.\label{loose-incentives} Without reputation, reciprocity and retaliation it is hard to establish incentive schemes for nodes to not be selfish, in particular in a privacy preserving manner. A solution to this problem is increasing transparency of actions, e.g. by having witnesses to report on malicious nodes in a privacy-preserving manner~\cite{ZhuSJ06b}. However, the most popular approach is the use of (anonymous) payments that incentivize good and collaborative behavior that benefits all users in the network~\cite{BelenkiyCEJKLR07,ChenSC09,KumaresanB14}. In contrast, one example of negative reinforcement is the tit-for-tat strategy to encourage users to share blocks to incentivize sharing, as in BitTorrent.

\vspace{2mm}
\para{Insights}.
\begin{itemize}
    \item \textit{Decentralized designs may prevent conventional attacks but also introduce new ones. Unless they are carefully designed, they may expose personal information to more, rather than fewer parties; and the need to perform joint computation across many authorities introduces threats to integrity.}
    \item \textit{Decentralized systems are particularly susceptible to traffic analysis, compared with centralized designs, since their distributed operations are mediated through networks and adversarial nodes that may use meta-data to compromise privacy.}
    \item \textit{Decentralized systems by nature require complex management of routing, naming and consistent state -- due to the lack of a central coordinator. Conventional defences against network attacks, like denial of service, require centralization and cannot be straightforwardly applied.}
    \item \textit{Sybil attacks are the great unsolved problem of decentralized systems that allow open and dynamic participation. Solutions based on social networks rely on fragile social assumptions; admission control through identification or payment re-introduce centralization. Proof-of-work defences increase the cost of participation.}
\end{itemize}
\subsubsection{Centralization of Network Information \& Computations}
\label{sec:centralizeddirs}
In any decentralized system routing packets across the network is a challenge for both operational and privacy reasons. Typically routing can be divided in two main task. The first task is how to find candidate nodes to relay traffic, and second task is how to select among these nodes. While as detailed in Sect.~\ref{topology}, there are many decentralized algorithms to choose the route, actually finding candidate nodes is difficult, as highlighted in Sect.~\ref{sec:lose}.

\vspace{2mm}
\para{Centralized Directories.} A common solution for the first problem is to assume that there exists a centralized directory that knows all network members. The most prominent example is the Domain Name System (DNS) that resolves easy-to-remember domain names to associated IP addresses in order to allow finding hosts in the largest known decentralized system: the Internet. Though distributed, this centralized service has serious security implications, e.g. for privacy~\cite{MonroseK10} or availability~\cite{VerkampG12}, and thus several alternatives are being proposed~\cite{WachsSG14} and deployed~\cite{DotBit}. Another example are Tor Directory authorities~\cite{DingledineMS04} that provide Tor clients with the full list of onion routers. These directories solve the discovery problem but have become a bottleneck for the scalability of the system~\cite{McLachlanTHK09}.
How to decentralize these authorities in an efficient, privacy-preserving manner is an active area of research. Solutions are based on having multiple copies of the publicly verifiable directory kept consistent via consensus protocol and distributed via gossiping, although it risks covertness; or to use friend-of-a-friend discovery and routing~\cite{MittalOTBG11,McLachlanTHK09}.

\vspace{2mm}
\para{Path Selection}. Once routing alternatives are known the question remains: Which route to choose? Thus typically, a centralized server is considered that can ``rank'' routing options to allow for path optimization with respect to adversaries~\cite{AkhoondiYM12,BackesKMM14,EdmanS09,JuenJDBC15}, performance~\cite{SherrBL09,SnaderB08,WacekTBS13}, or with respect to users' reputation~\cite{WangLBH13}. Such a centralized ranking approach has been shown to be vulnerable to attacks~\cite{BauerMGKS07,BiryukovPW13}. Typically DHTs are the possible solution, although only a few have the necessary security and privacy properties for use in decentralized systems~\cite{danezis2005sybil}.

\vspace{2mm}
\para{Distributed Computations}.A number of decentralized systems are designed with the assumption that there is a central entity that performs computations on the data collected by the nodes in the system. Paradigmatic examples of this behavior are decentralized sensor networks~\cite{ChanP08,EschenauerG02,ZhuSJ06} where the challenge is to send decentralized measurements to a ``master'' node, but there exist other applications such as distributed network monitoring for intrusion detection~\cite{RajabMT05}, anonymous surveys~\cite{HohenbergerMPS14}, or private statistics~\cite{ElahiDG14} in which, even though nodes perform decentralized computations, interaction with a central authority is needed to produce the final result.

\subsubsection{Trust Establishment}
\label{sec:assumptions:trust}
A challenge when decentralizing networks is to ensure that nodes can be trusted to perform the actions they are assigned or can authenticate themselves as the intended receiver of a message. Often, to avoid dealing with this problem, a common implicit centralized assumption is that a set of trusted servers is assumed to exist, such as in Dissent~\cite{wolinsky2012dissent} or the Directory Authorities in Tor.

Decentralized trust establishment is still an open problem, though some of the excitement around mining in Bitcoin is precisely due to their attempt to avoid this problem and so build a `trustless' decentralized system.

\vspace{2mm}
\para{Authentication}. In general certificate infrastructures are not decentralized, e.g., PKI. Therefore, some decentralized systems rely on centralized certification authorities to authenticate nodes that can be used for secure routing~\cite{CastroDGRW02,StoicaMKKB01}, user authentication~\cite{BucheggerSVD09}, or to enrol users in the system in the context of anonymous credentials~\cite{CamenischHKLM06,CamenischL01,BelenkiyCCKLS09}, a privacy-preserving alternative for authentication without requiring user identification.
Such centralized authorities are simpler for deployability or usability, but become a single point of failure as pointed out by Lesueur et al. in~\cite{LesueurMT09}. They also introduce an imbalance of power unnatural for decentralized environments since they allow a single entity to revoke peers' authentication credentials. Many decentralized designs do not address authentication (e.g.~\cite{NilizadehJMBK12,SharmaD12}, see~\cite{PaulFS14} for more details), although work from TAOS~\cite{wobber1994authentication} and SDSI~\cite{rivest1996sdsi} onwards has been working in this direction~\cite{macaroons}. Authentication is useful to prevent Sybil attacks, and work on decentralized and privacy-preserving authentication via threshold cryptography is one promising solution ~\cite{maheswaran2013crypto}, as is the use of zero-knowledge systems for anonymous credentials~\cite{BelenkiyCCKLS09}.

\vspace{2mm}
\para{Authorization}.  Assuming the existence of a centralized entity is also common when it comes to storing and enforcing authorization policies, as highlighted by numerous efforts to decentralize policy management and enforcement from SDSI~\cite{rivest1996sdsi} to more recent systems ~\cite{Lesniewski-LaasFSMK07,LiWM03,WinslettZB05}. OAuth was designed to be federated in terms of authorization, but in practice only a few large providers use this standard~\cite{Seong10}. So if an adversary compromises a user's single authentication method such as a password, it can compromise them across multiple decentralized systems. Work descending from SDSI~\cite{rivest1996sdsi} to limited-time authorization via pseudonyms and blind signatures present one way forward to decentralize authorization~\cite{maheswaran2013crypto}.

\vspace{2mm}
\para{Abuse Prevention}. As mentioned in Sect.~\ref{sec:lose} accountability is a challenge in decentralized systems. Hence, existing abuse-prevention schemes end up relying on centralized parties, often determining global reputation scores. Solutions based on blacklistable credentials (anonymous credentials for which authorization can be selectively revoked) use a centralized authority for enrollment~\cite{TsangAKS07,TsangAKS08}, or to store blacklists~\cite{JohnsonKTS07,TsangKCS11}. Similarly, identity escrow~\cite{BiskupF00} or revocable anonymous communication solutions~\cite{ClaessensDGDPV03}, that allow for re-identification of misbehaving users require a centralized party that stores those identities. In practice, spam prevention in federated email systems also uses centralized lists of known spammers. Typically, these are built from pre-existing trusted social networks, and only recently have reputation systems such as AnonRep (based on homomorphic encryption and verified shuffles) allowed reputation to be done in a privacy-preserving and decentralized manner~\cite{zhai2016anonrep}.

\vspace{2mm}
\para{Payment Systems}. In many applications of decentralized services it could be desirable to count on a payment system to reward peers for their contributions. While many alternatives have been presented in the literature specifically aimed at peer to peer systems, e.g.~\cite{BelenkiyCEJKLR07,CamenischLM07,YangG03}, they inherently rely on a centralized authority that opens accounts (the bank) and sometimes even on other authorities that can act as ``arbiters'' in case of dispute~\cite{BelenkiyCEJKLR07}, or on authorities that record transactions to help taxation on the operations run in the system, even if the transactions are anonymized~\cite{Taler}. Decentralized crypto-currencies can help ameliorate this problem.

\vspace{2mm}
\para{Trusted Developer Community}. All decentralized systems work by virtue of having the nodes communicate via the same protocol. Thus, the actual software can be a centralized point of failure if the protocol is flawed. If the protocol is standardized or otherwise uniformly specified, the implementation of the protocol itself may be a failure. Furthermore, the developers themselves could be compromised. his danger is augmented by the software monoculture prevalent in deployed systems, that results in a bug in a popular platform capable of compromising a large set of authorities. One solution is to apply the technique of forcing public transparency and auditing of the integrity of the development process. Open-source development, done in public repositories, is increasingly required. Integrity is ensured via deterministic builds~\cite{reproducible} so that everybody can verify the genuine binary, and the authority to run new versions of the software remains in the hands of the operators. This approach is already followed by Tor and increasingly by Bitcoin, where the choice to deploy particular open-source code is up to miners.

\vspace{2mm}
\para{Insights}.
\begin{itemize}
    \item \textit{Many decentralized systems implicitly rely on centralized components to hold network information for efficient routing or for establishing trust and defending against Sybil attacks.}
    \item \textit{Essential user-facing infrastructure, from authentication to authorization is centralized even in decentralized systems. Developing alternatives seems to be an open problem, with no clear established design. For payments, Bitcoin has recently provided a decentralized solution, but it suffers from a number of scalability, privacy, and financial volatility problems.}
    \item \textit{The developer community of a system is usually an implicit centralized authority, making social attacks on the developer community itself one of the largest dangers to any decentralized system.}
\end{itemize}

\subsection{Address Decentralization's Shortcomings}\label{sec:recover}

To build the next generation of decentralized systems, good will, slogans, and demands are not enough. What is needed is a clear research plan. A number of designs we review consider decentralization as a goal and virtue in itself and do too little to address the inherent challenge of maintaining privacy properties and deployment with high availability. In particular we studied in Section~\ref{sec:lose} a number of those challenges: an increased attack surface, with corrupt insiders; susceptibility to peers violating privacy and vulnerability to traffic analysis, integrity and consistency attacks; expensive and fragile routing; potential degradation in performance; loss of central choke points to enforce security controls; peer diversity and lack of incentives. These are serious and real threats, and not acknowledging them and confronting them head on leads to weak systems that cannot credibly compete with centralized solutions. This is demonstrated by the failure of Ethereum to promptly address the DAO vulnerability~\cite{DAO}. Indeed, decentralization in the style of early BitTorrent simply ends up being an inefficient way to do redundancy and availability without a centralized authority --- and with no credible privacy properties. Likewise, Bitcoin and Ethereum provides this style of decentralization with the addition of integrity but their simplistic accountability designs harms privacy. Therefore, more research is required looking at systems such as Tor and Bitcoin as platforms rather than purely as channels, including understanding their interfaces, performance, quality of service guarantees and the privacy properties as a whole system in order to deliver better privacy properties.

Availability without centralization is a key promise of decentralized systems, but often fails when the system grows. The most important engineering challenge of those reviewed is that decentralized systems often do not scale and are inefficient in comparison to centralized systems. In practice, in a world with limited resources and investment, inefficient decentralization leads to a failure of decentralization. This problematic dynamic is built into decentralized designs: maintaining high-integrity requires a majority to honestly participate in decisions. Although one could point to Bitcoin as a success, the larger Bitcoin network of miners grows the less it scales, as all miners need to detect and verify new blocks and transactions. Even worse, Ethereum smart contracts are executed on each node in the network. In both Bitcoin and Ethereum, as the number of nodes grows, the system gets slower. Due to this unfortunate design flaw, Bitcoin and Ethereum will face serious issues when scaling without major design changes that accountability as such does not address. We can be assured the current generation of attempts to ``re-decentralize'' the Internet will fail without more research on how to scale efficiently.

Finally, there has to be a deeper acceptance that even honest users and peers in decentralized systems will have to be incentivised to participate and behave cooperatively. This is particularly true when stronger privacy protections are implemented and reputation based on repeated and iterated interactions cannot be leveraged. In those cases standard platforms must be developed to prevent Sybil attacks and establish privacy preserving reputation to curtail abuse; accounting and payment mechanisms need to be devised to ensure that those that do work are rewarded to sustain their operations. Systems that do not provide incentives for participation in the infrastructure will fall foul of the tragedy of the commons and will remain mere proofs of concepts.

Even with motivated users, human fallibility must be addressed realistically. Decentralization advocates desire of users to return to a `lost golden age' of self-hosting services, as in the `re-decentralize' project~\cite{redecentralize}. However, the popularity of services like Facebook and Gmail shows that most do not have the time or skills to host decentralized nodes unless a powerful incentive exists such as file-sharing.
Worse, users may not be qualified at protecting their own systems, when even most skilled professional administrators cannot. Building successful decentralized systems that do not betray the security and privacy of their users is hard, and entails much more than tacking a blockchain or P2P network to a pre-existing problem, but also has to take into account platform security and ease of user operations.

\subsection{Develop Design and Evaluation Strategies}
Systems that claim to be decentralized today simply often use the adjective in an informal manner, resulting in decentralized ``snake oil'', as is the case for some blockchain-based start-ups. Unlike formal security definitions, information-theoretic definitions of anonymity, and differential privacy, there are no coherent quantitative metrics to characterize decentralization. Aside from having a common definition of the privacy and security properties, decentralization engineering also requires the development of design strategies that measure both decentralization and its effect on the properties systematized earlier.  More often than not, properties are neglected, rarely mentioned or evaluated, including the impact of decentralization and availability. Section~\ref{sec:how}, for instance, illustrates the variety of options in this design space.

Beyond the impact of decentralization on availability, a key missing piece is a systematic means for evaluating the privacy and security properties provided by a given decentralization system. As we evidence, decentralization can support privacy in many ways (Section~\ref{sec:privacy}), as well as supporting other properties too (Section~\ref{sec:gain}). We observe that systems are often designed with one particular privacy goal in mind, which is frequently redefined to suit the design, and system designers tend to resort to ad-hoc evaluation. A particular case in which a lack of systematic evaluation has great impact in terms of understanding the protection provided by decentralized system is the case of compound systems (i.e, systems that combine different schemes to try to improve overall protection); or the case where systems are deployed in environments with different characteristics than those assumed in their design. In decentralized systems, it is not granted that the protection of the whole is greater or equal than the sum of the parts. In fact, the inverse may hold: combining different decentralized systems with different assumptions may violate the properties each system guarantees by itself. For example, while a user may assume using BitTorrent over Tor provides anonymity for file-sharing, in fact the reverse holds: Tor provides no anonymity to UDP-based systems like BitTorrent, and users can even be deanonymized by virtue of running BitTorrent~\cite{le2010anonymizing}. In other words, systems to not exist in a vacuum. Their analysis and evaluation needs to account for interactions with their environment or other systems.

A similar trend is observed in terms of measuring the severity of disadvantages introduced by decentralization. Though, as we show in Section~\ref{sec:lose}, many weaknesses arise from decentralizing, few works evaluate their implications, or do so in a design specific way that is difficult to extrapolate to other systems. As a result it is extremely difficult to compare systems and find promising new directions. This slows the development of robust decentralized systems by obscuring good design decisions. For example, in many systems there is a trade-off between privacy and availability.

Further work is also required to radically simplify the deployment and management of ``real-world'' decentralized applications, either on larger platforms or as stand-alone distributed systems. Deployability and usable application life-cycle support is at the heart of the current centralized cloud-based `dev-ops' revolution, and has made centralized app stores and Web applications as popular as they are. Yet, there are no equivalent tools or technologies to facilitate the deployment, management, and monitoring of decentralized systems, let alone their continuous updates, application life-cycle management, and telemetry. This gap negatively affects developer's productivity and makes the engineering and maintenance of decentralized systems very expensive. Building toolchains that support easy management -- without introducing any central control -- is largely an open research problem. Successful projects such as Tor and Bitcoin have developed best practices and running code in that space such as open-source development and \textit{reproducible builds}~\cite{reproducible} to address security concerns that may be generalized.

\vspace{2mm}
\para{Key Research Questions for Decentralization}.
\begin{itemize}
\item \textit{Are there generalized techniques to provide privacy and integrity properties for decentralized systems without damaging availability?}
\item \textit{Can we develop systematic techniques to evaluate decentralized systems both in isolation and when they are deployed in different environments?}
\item \textit{How can human users be incentivised to work in a decentralized manner?}
\item \textit{How do real-world deployment of decentralization lead to scalability challenges that change the desired properties and defeat decentralization?}
\item \textit{Can we develop a mathematical metric to define degrees of decentralization?}
\end{itemize}

In the next section we will provide provisional answers to these questions to guide future research. These answers will be based on the observations built in previous sections.

redpajama_set_name: RedPajamaArXiv


Check out their new song called "April" and stay tuned for more – hopefully soon a full stream of the record will appear.
SURCO draw influence from bands like BLOC PARTY, AT THE DRIVE-IN, and TYPE-O-NEGATIVE!
Hey small love did you give it away did you say too much?


Take the A1 southbound and exit at Firenze Impruneta. From the roundabout, take the Florence-Siena road towards Siena and exit at Poggibonsi Nord. Follow the signs to San Gimignano for about 11 km and, once arrived at the roundabout entrance at San Gimignano, turn left towards Volterra, Castelsangimignano, Racciano. Continue on the main road SP47 for about 2 km. Turn left at the sign Pescille - The Bucciano Farm.
Take the A1 northbound and exit at Valdichiana. Follow the signs for Siena. From there take the Siena-Florence road in direction Florence. Exit at Colle di Val d'Elsa or Poggibonsi Sud or Nord and follow the signs to San Gimignano. Once at the roundabout at the entrance of San Gimignano, turn left towards Volterra, Castelsangimignano, Racciano. Continue on the main road SP47 for about 2 km. Turn left at the sign Pescille - The Bucciano Farm.


text:
2009 February Signature Music & Entertainment Memorabilia AuctionAuction #7004
J. D. Sumner's The Three Nails Stage Worn Costume.... (Total: 5 Items)
J. D. Sumner's The Three Nails Stage Worn Costume. Includes the robe, sandals, and pouch worn by onetime Elvis Presley back-up singer J. D. Sumner in the lead role of "Josh" in the highly acclaimed musical drama production of 1971 from Gospel Festival, U.S.A. -- The Three Nails. The costume is accompanied by a sealed LP copy of the cast album, program book, promo handbill, and a three-page contract dated June 10, 1970 and signed by the late Dottie Rambo, the Oak Ridge Boys' William Lee Golden, and of course, the late J. D. Sumner. The costume and LP are in Excellent condition, and the documents are in Very Fine condition. From the J. D. Sumner Archives. Accompanied by a letter of provenance from Shirley Sumner Enoch.
21st-22nd Saturday-Sunday
Heritage helped us feel we served the memory of our uncle with respect for his life's work and Heritage reflected that respect. You make a great team and gave us all a most memorable experience. We hope to work with you again some time in the future.
C., A., L., & H. G.,
Northport, NY