digital signature
Digital signature (also known as public key digital signature) is an ordinary physical signatures on paper of a similar, but uses a public key encryption technology in the field of implementation, a method for identification of digital information. A digital signature is usually defined two complementary operation, one for signing and another for verifying.
Digital signature, the sender is the only other people in order to produce the information can not be forged for a string of numbers, this string of numbers but also send a message to the authenticity of the sender information of a valid proof.
Digital signature asymmetric key cryptography and digital digest application technology.
Chinese name
digital signature
Foreign Name
digital signature；digitally signed
nickname
Public key digital signature
Category
A physical signature
table of Contents
principle
The integrity of the file's digital signature is easy to verify (no Jifeng , straddle signature does not need to handwriting experts), but also has a digital signature non-repudiation (non-repudiation).
Simply put, the so-called digital signature is added to the data unit some data on, or made the data unit code conversion. This allows the data conversion or data unit receiver to confirm the integrity of the source data unit and a data unit and to protect data from being (e.g. receiver) forgery. It is in the form of an electronic message to a method signature, a message can be signed in a communication network transmission. Based on public key cryptography and private key cryptography can obtain a digital signature, it is mainly based on public key cryptography digital signature. Including ordinary and special digital signature digital signature. Ordinary digital signature algorithm has RSA, ElGamal, Fiat-Shamir, Guillou- Quisquarter, Schnorr, Ong-Schnorr-Shamir digital signature algorithms, Des / DSA, Elliptic Curve Digital Signature Algorithm and Finite Automata digital signature algorithm. There are special digital signature blind signature , proxy signature, group signature , undeniable signature, fair blind signature, threshold signature, with a signed message recovery, etc., it is closely related to the specific application environment. Clearly, the digital signature of the application related to legal issues, the federal government based on the finite field discrete logarithm problem has developed its own Digital Signature Standard ( DSS ).
The main function
Ensure the integrity of the sender of the information transmitted authentication , to prevent the occurrence of transaction repudiation.
Digital signature technology is summary information encrypted with the sender's private key, the text is transmitted to the receiver together. Only the recipient of the sender's public key can decrypt the encrypted summary information, and then use the HASH function to receive the original produce a summary information, the summary information compared with the decryption. If so, then the information received is complete and has not been modified in transit, or explanatory information has been modified, the digital signature can verify the integrity of the information.
A digital signature is encrypted process, digital signature verification is a decryption process.
The signing process
When sending messages, the sender generates a hash function with a text message from the message digest , and then use their private key to encrypt this summary, this summary of the encrypted message as digital signatures and message transmitted together to the recipient, the recipient first sender with the same hash function to calculate the message digest from the received original message, and then using the public key of the sender of the message to additional digital signature decryption, if the two digest the same, then the recipient will be able to confirm that the digital signature of the sender.
Digital signature, there are two effects: First, can determine if the message is indeed a concurrent out by the sender signatures, because others can not fake signature of the sender. Second, the digital signature can determine the integrity of the message. Because digital signature features is that it represents the characteristics of the file, if the file is changed, the value of the digital digest will also change. Different files will get a different digital digest. A digital signature related to a hash function, the sender's public key , the sender's private key .