RSA: The public key encryption algorithm (RSA) is the first algorithm that can be used for data encryption and digital signature. IDEA: The International Data Encryption Algorithm (IDEA) is a block encryption algorithm. It designs a series of encryption rounds, and each round of encryption uses a subkey generated by a complete encryption key. RC4:RC4 algorithm is an encryption technology in the field of electronic information, which is used in wireless communication networks. It is an electronic password, and only authorized users can enjoy this service. MD5: The full name of MD5 is Message-Digest Algorithm 5, which allows a large amount of information to be "compressed" into a confidential format before signing the private key with digital signature software.