Digital signature is a digital string that only the sender of information can produce, and others can't forge it. This number string is also an effective proof of the authenticity of the information sent by the information sender.
It is a method to authenticate digital information, which is similar to the ordinary physical signature written on paper, but it is realized by using the technology in the field of public key encryption. A set of digital signatures usually defines two complementary operations, one for signing and the other for verification. Digital signature is the application of asymmetric key encryption technology and digital digest technology.
Network security, mainly network information security, needs to take corresponding security technical measures and provide appropriate security services. As one of the means to ensure the security of network information, digital signature mechanism can solve the problems of forgery, denial, counterfeiting and tampering. One of the purposes of digital signature is to replace the traditional manual signature and seal in the network environment, which plays an important role.
Signature process
When sending a message, the sender uses a hash function to generate a message digest from the message text, and then encrypts the digest with the sender's private key. The encrypted digest will be sent to the receiver as the digital signature of the message.
The receiver first calculates the message digest from the received original message with the same hash function as the sender, and then decrypts the digital signature attached to the message with the public key. If the two digests are the same, the receiver can confirm that the message belongs to the sender.