Re: Proof-of-Approval: A Better Blockchain Consensus Protocol

Hello Fresheneesz,

Quote from: fresheneesz on March 21, 2018, 01:55:32 AM

The image of how blocks are set up (https://cdn-images-1.medium.com/max/1000/1*fPsB4-t6J_1u1UpF37dYHw.png) reminds me strongly of the way blocks are chained in the "two-hop blockchain" (https://eprint.iacr.org/2016/716.pdf). I would like to see more in-depth comparisons to other consensus protocols, especially DPoS which seems particularly close in mechanism to Proof-of-Approval.

Comparing Proof-of-Approval with 2-hop Blockchain (2-hop)
1. 2-hop uses PoW consuming resources (in addition to PoS), Proof-of-Approval has no PoW.
2. 2-hop's alternate blocks are different, one is from PoW and the next is from PoS. All Proof-of-Approval blocks are the same (but each block has 2 parts to it).
3. In 2-hop, during PoS round, the network choose one stakeholder for PoS block. In Proof-of-Approval any (or all) stakeholders approve blocks.
4. In 2-hop, fork selection is based on the longest PoW chain. In Proof-of-Approval fork selection is based on a better approval score.
5. Proof-of-Approval has 1 block finality. 2-hop's finality properties seem to be similar to PoW chains. The analysis here is more difficult since neither PoS nor PoW can be analyzed independent of each other. The PoS part of the analysis matches Cardano's Ouroboros (https://eprint.iacr.org/2016/889.pdf) static case. Since the static case isn't a reality (stakes will change during chain's lifetime), it is unclear if the PoS does add any additional security to the chain.

Hope this comparison helps.
Regards,
Shunsai