Brief introduction of digital signature.
Digital signature (also known as public key digital signature) is a digital string that can only be generated by the sender of information, and others cannot 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.
2. Principles
The integrity of digital signature documents is easy to verify (no experts in printing, signing or handwriting are needed), and the digital signature is undeniable.
Simply put, the so-called digital signature is some data attached to the data unit, or the cryptographic transformation of the 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.
3. Characteristics
Everyone has a pair of "keys" (digital identities), one of which is known only by her/him (private key) and the other is public key (public key). Use the private key when signing and the public key when verifying the signature.
And because anyone can claim that she/he is you, the public key must be registered with the person (certification authority) that the receiver trusts. After registration, the authentication institution will issue you a digital certificate. After signing the document, you send this digital certificate to the receiver together with the document and signature, and the receiver asks the authentication institution whether it is really a document signed with your key.