isn't this what happened to the ps3? the documentation said "use a random number" and they calculated it once and put it as a constant instead of...yah know...using a random number (each time)?
For more info see for example:
* https://www.cs.uaf.edu/2012/fall/cs441/students/sc_ps3.pdf
* A presentation at CCC about how hackers broke the different security features or PS3 including ECDSA https://media.ccc.de/v/27c3-4087-en-console_hacking_2010#t=2...