sign in
oc · cosign
§ signin

sign in to oc cosign.

New here? Start with just your email — we’ll send a one-time code. Or continue with Google or GitHub. No password, nothing to create. Already hold a Bitcoin wallet? You can sign in with that too. Either way, it’s the same identity across every .ochk.io product.

§ bitcoin wallet

Sign in with any BIP-322-capable Bitcoin wallet (Sparrow, Xverse, Leather, UniSat, Alby, OKX, Phantom). Paste your address, click sign — your wallet extension prompts for a one-time signature on a short challenge. The address becomes your OC identity. Private key material never leaves your wallet.

> Detection picks the first installed BIP-322-capable extension. Address is the one your wallet will sign for.

OC Cosign never holds your keys and never takes custody of a single sat. Proving a Bitcoin address is an optional upgrade later — never required to get in.

how it works →ochk.io ↗