sign in
oc · cosign
§ signin

sign in to oc cosign.

New here? Start in seconds with Google, GitHub, or your email — we’ll send a one-time code. No password, nothing to create. Already hold a Bitcoin wallet? Sign in with that for full self-custody. Either way, it’s the same identity across every .ochk.io product.

§ email + otp

We email you a 6-digit code. No password, and no wallet needed to start. Link a Bitcoin address any time — that is the identity you hold yourself.

> Codes come from the auth host, expire in 10 minutes, and work once.

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 ↗