Chainark

An open-source ZKP library to prove chain-like structure with a single proof. It is developed on top of gnark but could also be ported to other proving libraries. We use chainark to prove the deposit transaction when the user deposits some Bitcoin to our designated address to mint $zkBTC in Ethereum. With chainark we could prove whole bitcoin history from the genesis block, over and including the block where the deposit happens, to some blocks further to ensure confirmation depth. Other security designs are in play, but let’s discuss them later.