The blog post: https://blog.cosmos.network/sifchain-announces-peggy-cosmos-ethereum-cross-chain-bridge-eeb46a8f91db contains several factual inaccuracies that we would like to see corrected.
The post incorrectly claims that Althea's Peggy uses "Proof of Authority" and that a "select set of pre-ordained validators" control the bridge. This is simply wrong. Peggy processes transactions signed by the current validator set on the Cosmos chain. The only entities that a user of Peggy must trust are the Cosmos validators. Using the terms "select set of pre-ordained validators" and "proof of authority" gives readers of this blog post a false impression of how Peggy works. If Peggy is "Proof of Authority", then the Cosmos Hub is also "Proof of Authority".
The blog post includes a quoted paragraph from our documentation where we discuss the fact that 66% of the validators of any proof of stake chain control the assets secured by that chain, and if the value of assets secured by the chain exceed it's staking token's market cap, this could provide an incentive to attack the chain.
The blog post then makes the claim that Sifchain is somehow not vulnerable to this attack, while Althea Peggy is. The fact is that every Cosmos SDK chain (and every other PoS platform) is vulnerable to a 66% attack. Claiming otherwise misleads the reader.
We don't mind Sifchain comparing our two approaches, and we don't mind if they think their approach is better. It's arguable whether an official Cosmos blog is the appropriate venue for Cosmos projects to dunk on each other, but that's your editorial prerogative. We simply want the factual inaccuracies in this blog post corrected, and a notice of the correction placed on the post, as is normal practice in most publications. If you replace the 3 incorrect paragraphs quoted below with our suggested paragraph, this will correct the post.
Current incorrect paragraphs:
The difference in the two lies in their cryptoeconomic security model. Althea Peggy uses a Proof of Authority model in which users accept the credibility of a select set of pre-ordained validators that operate the Peggy bridge. A cross-chain transaction is verified if the pre-ordained validators declare it valid above a certain threshold.
Althea Peggy Documentation: Validators are fully trusted to manage the bridge. Validator powers and votes are replicated on the Ethereum side so trust in bridge assets depends entirely on trust in the validator set of the peg zone chain. This has known problems where the assets in the bridge exceed the market cap of the native token. We accept these known issues in exchange for the dramatic design simplification combined with acceptable decentralization this design provides. https://github.com/cosmos/peggy/tree/althea-peggy
By contrast, Sifchain uses a Peggy deployment with a Staked Threshold model in which Peggy validators stake collateral to secure the bridge and they are subject to slashing as per Tendermint consensus rules on both the Cosmos SDK chain and the Ethereum smart contract side of that bridge. This solves the aforementioned cryptoeconomic security issue on the bridge. In exchange for being subject to slashing, validators earn a service rate. Althea trades off trust minimization in exchange for simple design whereas Sifchain trades off simple design for maximizing trustlessness supported by cryptoeconomic incentives.
Suggested correction:
Sifchain uses a Peggy deployment with a Staked Threshold model in which Peggy validators stake collateral to secure the bridge and they are subject to slashing as per Tendermint consensus rules on both the Cosmos SDK chain and the Ethereum smart contract side of that bridge. In exchange for being subject to slashing, validators earn a service rate. Althea's Peggy uses slashing only within the Cosmos SDK module, giving the bridge security equivalent to the Cosmos chain it is running on.
There is also a diagram which incorrectly associates the words "Proof of Authority" with Althea Peggy. If you simply erase "Proof of Authority" from this diagram, it will be OK.
Thanks! :)