party's signature and return receipt

The three most widely used algorithms of digital signature are haah signature, DSS signature and RSA signature.

A signature system generally consists of two parts: Signature Algorithm and verification algorithm. 3) Digital envelope digital envelope uses cryptographic technology to ensure that only the specified recipient can read the content of the information. Private key cryptosystem and public key cryptosystem are adopted in the digital envelope. 4) Pgppgp (pretty good privacy) is a mail en