One of the major architectural aspects of the blockchain is that blocks are distributed across the P2P network.
- The P2P network is a network wherein each node of the network is connected to every other node of the network.
- These are the nodes which also helps to store the blocks as well as to do some mining process on the blocks as per the criteria which are mentioned in the blockchain algorithm.
- The arrangement with which the blocks and the Ledger’s are distributed across the various nodes of the network is also called distributed ledger technology or DLT.
- The DLT is also abbreviated as the alternative name of blockchain in order to make it look more generic.
Each Node or Peer contain an entire copy of the blockchain: P2P Network
- So let’s say these are the nodes of the network.
- Each block of the network will have the entire copy of the blockchain.
So let’s say for example we have three blocks in the blockchain named A, B, C. And we have got five nodes in the network. Then each of the nodes will have all the three copies of the blockchain.
Whenever a New Transaction is Added to the System
- So what happens when a new transaction gets added to the system.
- That is what happens when a new block is also added to the system.
- In this case, what happens is whenever the initiator of the transaction that is the node in which is going to add this particular transaction adds the block.
- It is first validated by that particular node.
- Once it gets validate its adds to the current copy of the blockchain.
- Then it gets broadcast to all the nodes of the P2P network.
So let’s say for example the node has validated block D. It gets to add to its copy of the blockchain. Now, block D gets broadcast across all the nodes. All these broads are responsible to validate the block. Once all the nodes receive the broadcasted block. Then validate block will get added to their copy of the blockchain.
- Added in the block.
- Block gets broadcast to all nodes.
- Each node performs validation.
- If eligible blocks are added
Purpose to have P2P Network
So one of the questions which may come to our mind that what is the purpose of such a P2P network arrangement in the blockchain. For that let us recall to one of the design goals of blockchain was that to eliminate a need for a trusted third party. Now blockchain has a new way of doing it by saying that this P2P network will help us to remove the central trusted third party requirement. It establishes a transaction without the need for a trusted third party.
The concept to establish a trust framework without the need for a Prostate third party is possible. When most of the nodes in the network have a valid copy of the blockchain containing the valid transaction entries and that is possible when the majority of the nodes in the network agree to a common copy of the blockchain and that copy is a valid copy of the blockchain.
- The purpose to have P2P Network is to establish a trust framework.
- Without the need of Central Trusted Third Party.
So let’s say for example all the nodes in the network which are having the correct copy of blockchain with the correct transaction data are the honest nodes. The one which are under the influence of the attacker and which are having the wrong copy of the blockchain that are the fraudulent nodes. So in this case,
- If 51% of the nodes remain the honest nodes.
- Then the blockchain algorithm says that it will be very difficult for the fraudulent nodes to catch up.