Chain-key Bitcoin

Chain-key Bitcoin (ckBTC) is a Bitcoin "layer 2" built on top of the Internet Computer blockchain (IC). It enables both individuals as well as IC smart contracts to transact the deposited Bitcoin cheaply and with a much higher throughput compared to the Bitcoin network. Crucially, ckBTC has no additional trust assumptions other than those of the IC itself (roughly, a 2/3 majority of honest nodes). In this talk, I will give an overview of our ckBTC development, from the underlying novel threshold ECDSA scheme that allows IC smart contracts to sign arbitrary messages, through how this scheme is leveraged by the conversion logic between Bitcoin and ckBTC, to the formal verification of that logic.