Cardano founder Charles Hoskinson has announced the launch of Cardinal, the first Bitcoin DeFi protocol on the Cardano network. The protocol leverages MuSig2 multi-signature technology to enable non-custodial cross-chain functionality, allowing users to directly use Bitcoin UTXOs for lending and staking on Cardano. It also supports Ordinals inscriptions as collateral. Cardinal is the first solution enabling Bitcoin to access the Cardano ecosystem without requiring custody.