Difference between ethereum blockchain and Hyperledger blockchian

Question

I have found the answers for this question, but still not getting proper answers, that's why I am posting it here for going into dive deeper.

I just came to know that Hyperledger in permissioned network while Ethereum is public. But I am not getting proper idea about the consensus mechanism inside both the blockchains. May be consensus mechanism makes more sense to understand the difference between them.

Can anyone have any proper explanation or updated reference link for that ?

Answer 1

Both permissioned (or private) and public blockchains have consensus algorithms and share the same algorithms. Generally consensus algorithms fall into 2 classes:

• Nakamoto-style or Lottery consensus. Tends to be used by public blockchains (including Bitcoin's PoW)
• Voting consensus. Tends to be used by private blockchains

The above public/private blockchain rule is not absolute. For example Hyperledger Sawtooth uses PoET consensus, which is a lottery consensus algorithm, but Sawtooth is a permissioned blockchain

Here's a small sample of consensus algorithms:

• PoW Proof of Work. Completing work (CPU-intensive Nakamoto-style consensus algorithm). Usually used in permissionless blockchains.
• PoET Proof of Elapsed Time uses a randomly generated wait time value to choose a leader. The node with the first expired timer wins.
• PBFT Practical Byzantine Fault Tolerance uses leader and block election. Not very scalable due to the large number of messages sent between nodes
• RAFT Consensus algorithm that elects a leader for a term of arbitrary time. Leader replaced if it times-out. Raft is faster than PoET, but is not Byzantine Fault Tolerant (not BFT) because it cannot withstand hostile nodes. Also Raft does not fork.