<p>A block chain:</p>

<p>Block - a chunk of data </p>

<p>Chain - a sequence of links</p>

<p>So you need some data, and you need it to be inviolably linked to another block of data (repeatedly) forming a chain. In essence you take your first block of data, hash it, and append the first hash to the first data. For your second block of data, you include the first hash in the second block of data, the ph hash the whole lot to get your second hash. The second hash forms part of the data in the 3rd block. In pseudocode</p>

<pre><code>Hash1=calc_hash(Data1)
Block1=Data1+Hash1
Hash2=calc_hash(Hash1+Data2)
Block2=Data2+Hash2
Hash3=calc_hash(Hash2+Data3)
Block3=Data3+Hash3
</code></pre>

<p>This is how the chain link between blocks is established - the hash from block N is involved in calculating the hash for block N+1. If you alter the data for block N, the hash will fail. If you calculate a new hash and try to pass it off as legit, the hash for block N+1 will fail.. and so on</p>

<p>It’s not new.. for many years longer than bitcoin has existed credit card terminals in certain countries have been communicating using a protocol that hashes each transaction and uses part of that hash in hashing the next transaction. It provides tamper deterrence/checking and also allows some nifty tricks such as telling the bank in a subsequent transaction whether the previous transaction was voided or not. Bitcoin might well pack many transactions into a block but it doesn’t have to- the credit cards terminals I mentioned for example, have a single transaction per hashed block</p>

CC BY-SA 4.0
2018-10-28T18:56:14.220Z
2018-10-28T19:07:26.610Z
2018-10-28T19:07:26.610Z
Caius Jard
<p>Trying as much as possible to understand what Blockchain technology is (As i am trying to see if i can be a Blockhain developer) and I just worked on a money transfer system myself and i hear everyone talking about blockchain being the next to important thing in order to develop a money payment system.</p>

<p>following what i read on the internet , a system using blockchain technology should have the following capabilities,</p>

<p>1.) After making the Payments should generate the block and generate the block hashes and save them to be used as a transaction Log Later on, in order to trace the history of the payments from the beginning till its present state... 2.) Peer-to-peer Allowing users to make payments and view track of the transactions etc</p>

<p>Now i want to understand in its short meaning, its this what blockchain is all about?</p>

CC BY-SA 4.0
2018-10-28T08:24:24.870Z
This is far too broad, and is missing several important points. I would strongly suggest reading a comprehensive guide such as Mastering Bitcoin, and coming back with specific questions.
Raghav Sood
CC BY-SA 4.0
2018-10-29T14:44:45.000Z
Agreed. Mastering Bitcoin is the goto introductory work that explains both in overview and in detail what Bitcoin and the Blockchain are for, and what problem it solves.
BlackBeltBob
<blockchain><payment-processors>
Explanation of Blockchain Payment systems
Anabel
# Explanation of Blockchain Payment systems

(Asked by: username_0 on 2018-10-28)

Trying as much as possible to understand what Blockchain technology is (As i am trying to see if i can be a Blockhain developer) and I just worked on a money transfer system myself and i hear everyone talking about blockchain being the next to important thing in order to develop a money payment system.

following what i read on the internet , a system using blockchain technology should have the following capabilities,

1.) After making the Payments should generate the block and generate the block hashes and save them to be used as a transaction Log Later on, in order to trace the history of the payments from the beginning till its present state... 2.) Peer-to-peer Allowing users to make payments and view track of the transactions etc

Now i want to understand in its short meaning, its this what blockchain is all about?

**Tags:** blockchain, payment-processors

> **Comments:**
> **username_1**: This is far too broad, and is missing several important points. I would strongly suggest reading a comprehensive guide such as Mastering Bitcoin, and coming back with specific questions.  
> **username_2**: Agreed. Mastering Bitcoin is the goto introductory work that explains both in overview and in detail what Bitcoin and the Blockchain are for, and what problem it solves.  

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## 1 answers

### Answer by username_3 on 2018-10-28. Score: 0

A block chain:
Block - a chunk of data 
Chain - a sequence of links
So you need some data, and you need it to be inviolably linked to another block of data (repeatedly) forming a chain. In essence you take your first block of data, hash it, and append the first hash to the first data. For your second block of data, you include the first hash in the second block of data, the ph hash the whole lot to get your second hash. The second hash forms part of the data in the 3rd block. In pseudocode
Hash1=calc_hash(Data1)
Block1=Data1+Hash1
Hash2=calc_hash(Hash1+Data2)
Block2=Data2+Hash2
Hash3=calc_hash(Hash2+Data3)
Block3=Data3+Hash3

This is how the chain link between blocks is established - the hash from block N is involved in calculating the hash for block N+1. If you alter the data for block N, the hash will fail. If you calculate a new hash and try to pass it off as legit, the hash for block N+1 will fail.. and so on
It’s not new.. for many years longer than bitcoin has existed credit card terminals in certain countries have been communicating using a protocol that hashes each transaction and uses part of that hash in hashing the next transaction. It provides tamper deterrence/checking and also allows some nifty tricks such as telling the bank in a subsequent transaction whether the previous transaction was voided or not. Bitcoin might well pack many transactions into a block but it doesn’t have to- the credit cards terminals I mentioned for example, have a single transaction per hashed block


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