Digital signature——

The difference between digital signature and public key encryption

Public key encryption ：
Alice use Bob The public key encrypts the message , Pass to Bob,Bob Decrypt with your own private key
digital signature :
Alice use Own private key For messages m Signature ,Alice The message is m And signature to Bob received m And after signing ,Bob use Alice To verify the validity of the signature

Digital signature and message authentication

Message authentication ：
When there is no conflict of interest between the sender and the receiver , Message authentication is sufficient to prevent third-party corruption .
* The recipient can verify whether the identity of the message sender has been tampered with
* The recipient can verify whether the content of the sent message has been tampered with

digital signature ： When there is a conflict of interest between the sender and the receiver , Simply using message authentication technology can not solve the disputes between the sender and the receiver . Digital signature technology must be used .
Digital signature can verify the authenticity of the source of the information 、 The authenticity of entity identity 、 It is undeniable
RSA Digital signature system