OpenBSD Journal

DSA removal from OpenSSH

Contributed by rueda on from the going-going dept.

The OpenSSH project has announced the timeline for the removal of DSA support from OpenSSH:

OpenSSH plans to remove support for DSA keys in the near future. This
message describes our rationale, process and proposed timeline.


DSA, as specified in the SSHv2 protocol, is inherently weak - being
limited to a 160 bit private key and use of the SHA1 digest. Its
estimated security level is <=80 bits symmetric equivalent[1][2].

OpenSSH has disabled DSA keys by default since 2015 but has retained
optional support for them. DSA is the only mandatory-to-implement
algorithm in the SSHv2 RFCs[3], mostly because alternative algorithms
were encumbered by patents when the SSHv2 protocol was designed and
In summary:

2024/01 - this announcement
2024/03 (estimated) - DSA compile-time optional, enabled by default
2024/06 (estimated) - DSA compile-time optional, *disabled* by default
2025/01 (estimated) - DSA is removed from OpenSSH

Please read the announcement message for full details.

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