Assets moving onto or off of Cryptos are held in custody by the validator set jointly, using threshold signature schemes — no single key, operator, or server can move bridged funds alone.
Bitcoin bridged onto Cryptos is held in a Taproot address the validator set controls jointly through threshold Schnorr signatures (MuSig2) — releasing BTC requires the validators to cooperatively produce a single aggregate signature, so no individual validator can authorize a withdrawal on their own. The wrapped representation on Cryptos tracks that custody 1:1.
ERC-20 assets move through a lock-and-release smart contract on the origin chain. A release requires signatures from a two-thirds majority of the validator set before the contract will pay out — the same security assumption as the chain's own consensus, rather than a separate bridge-specific trust model.
Support for additional origin chains, including Solana, is in active design — not yet live. This page will be updated as that work reaches the same validator-custody model used for Bitcoin and Ethereum today.