SHA-1 (deprecated)

wikipedia:SHA-1

Attacks

Certificates are at special risk to the aforementioned SHA1 collision vulnerability as an attacker has effectively unlimited time in which to craft a collision that yields them a valid certificate, far more than the relatively brief LoginGraceTime window that they have to forge a host key signature.

See also

• SHA, SHA-0, SHA-1, SHA-2, SHA-3, SHA-256, shasum, sha1sum, sha256sum, sha512sum