Digital signature

The so-called "digital signature" is to use some cryptographic operation to generate a series of symbols and codes to form an electronic password for signature, instead of writing a signature or seal. For this kind of electronic signature, The signature can also be technically verified, and the accuracy of its verification is unmatched by the verification of ordinary manual signatures and stamps. "Digital signature" is currently the most commonly used, technically mature, and most operable electronic signature method in e-commerce and e-government. It adopts standardized procedures and scientific methods to identify the identity of the signer and recognize the content of an electronic data. It can also verify whether the original text of the file has been changed during the transmission process, ensuring the integrity, authenticity and non-repudiation of the transmitted electronic file.

Digital signature is defined in the ISO7498-2 standard as: "Some data appended to the data unit, or a cryptographic transformation made to the data unit. This data and transformation allows the recipient of the data unit to use To confirm the source and integrity of the data unit and protect the data from forgery by others (such as the recipient)." The U.S. Electronic Signature Standard (DSS, FIPS186-2) explains digital signatures as follows: "The result of calculating data using a set of rules and a parameter, which can be used to confirm the identity of the signer and the integrity of the data." According to the above definition, PKI (Public Key Infrastructino) provides cryptographic transformation of data units, and enables the recipient to determine the source of the data and verify the data.

The core execution agency of PKI is the electronic certification service provider, commonly known as the certification authority (CA). The core element of the PKI signature is the digital certificate issued by the CA. The PKI services it provides are authentication, data integrity, data confidentiality and non-repudiation. Its approach is to use the certificate public key and the corresponding private key to perform encryption/decryption, and generate a signature and verification signature for the digital message. Digital signatures use public key cryptography and other cryptographic algorithms to generate a series of symbols and codes to form an electronic password for signature, instead of writing signatures and seals; this electronic signature can also be technically verified, and the accuracy of its verification is Verification of hand signatures and stamps is unmatched in the physical world. This signature method can be authenticated in a large trusted PKI domain population, or cross-certified in multiple trusted PKI domains. It is especially suitable for secure authentication and transmission on the Internet and wide area networks.

The biggest difference between "digital signature" and ordinary text signature is that it can use distinctive graphic files. You only need to use a scanner or drawing tool to create your personalized signature, seal or even photo. into a BMP file, it can be used as material for "digital signature".