How pbft is being used in blockchain?

0 votes
I am trying to understand how PBFT works?? With some knowledge that I have I understand how it is applied in hyperledger, my question is that for malfunctioned nodes if they keep failing to write block in chain they will form a different chain than a healthy node, now in the next consensus the existing node will be picked up, how do the nodes know which is the correct chain?
Apr 20, 2018 in Blockchain by anonymous
73 views

1 answer to this question.

0 votes

PBFT can tolerate byzantine failures. For tolerating faulty nodes it needs at least 3*f+1 nodes. Suppose there are f malicious nodes which are failing to add blocks in its chain, this will result in inconsistency, and then one can figure that the same chains from rest 2f+1 nodes are correct.

Also, correct nodes always output same data to the same request in same order. In PBFT identities of all nodes should be established, there should be central authority to find whether a node can join the network or not.

Now, this is needed because PBFT works by voting mechanism which is not a secure option For example, a proposed value by the primary only can be recorded to all nodes in the way of state machine replication, which it means that there needs at least 2f + 1 agreed matching messages for the value to be accepted to the correct nodes. Without the trusted identity management, Sybil attack is possible. And this is the main reason why PBFT is not for the open blockchain which allows any node can freely join or leave the network.

answered Apr 20, 2018 by Perry
• 17,010 points

Related Questions In Blockchain

+1 vote
1 answer

What is Ethereum Blockchain? Where is it being used?

Blockchain is a decentralized distributed database of immutable records, ...READ MORE

answered Apr 2, 2018 in Blockchain by Christine
• 15,790 points
45 views
+1 vote
1 answer

How is Blockchain used for provenance purposes?

Let me tell you how Blockchain could ...READ MORE

answered Apr 3, 2018 in Blockchain by Shashank
• 10,330 points
29 views
0 votes
1 answer

In a Blockchain, how difficult is it to modify the third to last block?

Technically, it's not difficult at all, all ...READ MORE

answered Apr 20, 2018 in Blockchain by Christine
• 15,790 points
61 views
0 votes
1 answer

How a transaction validity is verified in blockchain?

Blockchain has the records the of all ...READ MORE

answered May 11, 2018 in Blockchain by Johnathon
• 9,070 points
37 views
0 votes
1 answer
+1 vote
4 answers
0 votes
1 answer

How can i read headers of blockchain in multichain?

You could use a recent feature known ...READ MORE

answered Mar 26, 2018 in Blockchain by Perry
• 17,010 points
34 views
0 votes
1 answer

How secure is to implement blockchain at a smaller scale??

Blockchain relies on the number of nodes ...READ MORE

answered Apr 18, 2018 in Blockchain by Perry
• 17,010 points
29 views