[euclidean](https://web.archive.org/web/20230212044931/http://www-math.ucdenver.edu/~wcherowi/courses/m5410/exeucalg.html)
[ecdsa1](https://sefiks.com/2018/02/16/elegant-signatures-with-elliptic-curve-cryptography/)
[ecdsa2](https://learnmeabitcoin.com/technical/cryptography/elliptic-curve/ecdsa/)