1, RSA signature algorithm. The mathematical theory of this algorithm is based on the factorization of large prime numbers, which is the most popular signature algorithm at present, and its security depends on the difficulty of factorization of large numbers.
2.DSA signature algorithm. The mathematical theory of this algorithm is based on discrete logarithm problem over integer finite field, and its security strength and speed are lower than RSA algorithm.
3.ECDSA signature algorithm. Compared with the first two algorithms, this algorithm is different in the way of generating key pairs.