[Cryptography] Posting the keys/certs for: Two distinct DSA keys sign a file with the same signature. Is this repudiation issue?

[Georgi Guninski]

On Thu, Sep 29, 2016 at 10:22:10PM +0000, Kristian Gjøsteen wrote:
> These keys aren’t weak, they are invalid. The parameters used are not according to the standard.
>

Which is the standard?

URL please.