National secret is the national cryptography Bureau identified by the domestic cryptography algorithm. The main types are SM1, SM2, SM3, and SM4. Both the key length and packet length are 128 bits.
SM1 is symmetric encryption. Its encryption strength is comparable to AES. The algorithm is not public, and the algorithm needs to be invoked through the interface of the encryption chip.
SM2 is asymmetric encryption based on ECC. The algorithm is publicly available. Because the algorithm is based on ECC, its signature speed and key generation speed are faster than RSA. ECC 256 bits (SM2 is a kind of ECC 256 bits) have higher security strength than RSA 2048 bits, but the operation speed is faster than RSA.
SM3 message digest. You can use MD5 for comparison understanding. The algorithm is publicly available. The verification result is 256 bits.
SM4 wireless LAN standard packet data algorithm. Symmetric encryption, key length and packet length are 128 bits.