The paper also tentatively discusses several related encryption algorithms to improve the security and analyzes the plaintext key space, ciphertext key space and encryption strength.

The main principle is that before data communication, encrypts the message plaintext by using DES mode and encrypts DES key by using RSA mode and realizes the digital signature.

At the precision of 64 bits, even if a variable in the initial key has a minute difference about 10-15, any information about the original plaintext can't be obtained.