# How did this group discover m wasn't random?

In this video a group of "hackers" describe how they discovered private keys for the PS3 that was using this ECDSA algorithm by discovering that the "random" integer $$m$$ (or $$k$$ in the wiki link) was actually static, allowing the private key to be solved for. The attack is actually mentioned in the wiki link for the algorithm, and basically says the same thing as the video.

My question is, how did they discover $$m$$ was static, and how did they even know that particular ECDSA algorithm was used to generate the private key? Even once they knew these two things, wouldn't they need the particular curve sony used?

• What if the PS3 signs the same message again? What can you see if the random $k$ ($m$ in the video notation) is used again? Mar 4 '21 at 8:53