Hello Slava79,
Did you read Tendermint white paper ? I scanned article and the core of it looks quite similar to Tendermint's PBFT consensus. Could you please provide a comparison ?
Comparing Proof-of-Approval with Tendermint1. Tendermint is a PBFT (
http://pmg.csail.mit.edu/papers/osdi99.pdf) like algorithm where all nodes together agree on transactions and their order that would be put in a block. Therefore, all nodes together come up with a single block to be inserted in the blockchain. In Proof-of-Approval, just like Bitcoin, individual nodes bundle transactions on their own and the network chooses one of those bundles.
2. The "validators" in Tendermint volunteer to put some of their money as collateral that will earn them rewards but could also be confiscated. Validators are similar to those in Casper the Finality Gadget of Ethereum (
https://arxiv.org/pdf/1710.09437.pdf). This article compares the two
https://blog.cosmos.network/consensus-compare-casper-vs-tendermint-6df154ad56ae.
3. Tendermint a single "proposer" who proposes the blocks. The proposer is selected by some process from the validators in round robin.
4. Tendermint transactions achieve instant finality while Proof-of-Approval takes 1 block to finality.
5. Tendermint is likely to have less "liveness" than a block creating protocol like Bitcoin or Proof-of-Approval.
6. The amount need to takeover Tendermint is 1/3 of the collateral amount while the amount to takeover Proof-of-Approval blockchain would be almost half (just under half) of the value of the blockchain.
Regards,
Shunsai