Asymmetric encryption technology, also known as public key cryptosystem, uses different encryption keys and decryption keys, which is a cryptosystem that "it is computationally infeasible to derive decryption keys from known encryption keys".

Digital signature is based on public key cryptosystem, which can provide security that is difficult to achieve by other methods.

In computer communication, when the receiver receives a message, it often needs to verify whether the message has been tampered with during transmission, and sometimes the receiver needs to confirm the identity of the sender of the message, which can be achieved by digital signature.

In the process of digital signature, the sender's private key is used to encrypt the information digest, and the receiver uses the sender's public key to verify the signature, because the public key and private key are a pair of encryption and decryption keys, and the private key can only be used by the sender, thus ensuring the authenticity of the signature.