De-perimeterisation
In information security, de-perimeterisation is the removal of a boundary between an organisation and the outside world. De-perimeterisation is protecting an organization's systems and data on multiple levels by using a mixture of encryption, secure computer protocols, secure computer systems and data-level authentication, rather than the reliance of an organization on its network boundary to the Internet. Successful implementation of a de-perimeterised strategy within an organization implies that the perimeter, or outer security boundary, was removed.

Metaphorically, de-perimeterisation is similar to the historic dismantling of city walls to allow the free flow of goods and information. To achieve this there was a shift from city states to nation states and the creation of standing armies, so that city boundaries were extended to surround multiple cities.

De-perimeterisation was coined by Jon Measham, a former employee of the UK's Royal Mail in a research paper, and subsequently used by the Jericho Forum of which the Royal Mail was a founding member.

Potential benefits 
Claims made for removal of this border include the freeing up of business-to-business transactions, the reduction in cost and the ability for a company to be more agile. Taken to its furthest extent an organisation could operate securely directly on the Internet.

Operating without a hardened border frees organizations to collaborate, utilizing solutions based on a Collaboration Oriented Architecture framework.

Variations 
More recently the term is being used in the context of a result of both entropy and the deliberate activities of individuals within organizations to usurp perimeters often for well-intentioned reasons. The latest Jericho Forum paper named "Collaboration Oriented Architecture" refers to the trend of de-perimeterisation as a problem:
Problem
The traditional electronic boundary between a corporate (or ‘private’) network and the
Internet is breaking down in the trend which we have called de-perimeterisation.
 
Variations of the term have been used to describe aspects of de-perimeterisation such as:
 "You’ve already been de-perimeterised" to describe the Internet worms and viruses which are designed to by-pass the border using web and e-mail.
 "re-perimeterisation" to describe the interim step of moving perimeters to protection groups of computer servers or a data centre – rather than the perimeter.
 "Macro-Perimeterisation" the act of moving the security perimeter into "the cloud", see Security As A Service, examples of such security services in the cloud are exemplified by email cleaning services or proxy filtering services provided by towers in the internet.
 "micro-perimeterisation" moving the security perimeter to surround the data itself, interim steps might include moving the perimeter around individual computer systems or an individual application (consisting of a cluster of computers).

References

External links
 http://www.jerichoforum.org
 http://www.opengroup.org

Data security