Briefly describe the principle of digital signature.

A digital signature is just some data attached to a data unit, or an encrypted conversion of a data unit. This kind of data or transformation allows the receiver of the data unit to confirm the source and integrity of the data unit, and protects the data from being forged by people (such as the receiver).

This is a method of signing an electronic message, and the signed message can be transmitted in a communication network. Digital signature can be obtained based on both public key cryptosystem and private key cryptosystem, mainly digital signature based on public key cryptosystem. Include general digital signature and special digital signature.

Extended data:

Digital signature has two functions: first, it can be sure that the message is indeed signed by the sender, because others can't forge the sender's signature. Secondly, the digital signature can determine the integrity of the message.

Because the characteristic of digital signature is that it represents the characteristics of the file, if the file changes, the value of the digital abstract will also change. Different files will get different digital summaries. Digital signature involves hash function, sender's public key and sender's private key. "

Digital signature technology encrypts abstract information with the sender's private key and sends it to the receiver together with the original text. The receiver can decrypt the encrypted digest information only by using the sender's public key, and then use the hash function to generate the digest information for the received original text and compare it with the decrypted digest information. If they are the same, it means that the received information is complete and has not been modified during transmission, otherwise it means that the information has been modified, so the digital signature can verify the integrity of the information.

Baidu Encyclopedia-Digital Signature