The relationship between digital certificates and digital signatures

The connection between the two: A digital certificate is a file that is digitally signed by a certificate authority and contains the information about the owner of the public key and the public key. In its simplest form, a certificate contains a public key, a name, and a digital signature from the certificate authority.

Another important feature of digital certificates is that they are only valid for a specific period of time.

Note: Digital signature technology encrypts the digest message with the sender's private key and transmits it to the receiver along with the original text. The receiver can only decrypt the encrypted digest information with the sender's public key, and then use the hash function to generate a digest message for the received original text, which is compared with the decrypted digest message.

If it is the same, it means that the information received is complete and has not been modified during transmission, otherwise the message has been modified, so the digital signature can verify the integrity of the information.

The main differences are that the nature is different, the purpose is different, and the method is different, as follows:

First, the nature is different.

1. Identity authentication.

Identity authentication generally refers to identity verification, also known as "verification" and "authentication", which refers to the completion of the confirmation of a user's identity through certain means.

2. Digital signature.

A digital signature (also known as a public key digital signature) is a string of numbers that can only be generated by the sender of the message and cannot be forged by others, and this string of numbers is also an effective proof of the authenticity of the message sent by the sender of the message.

Second, the purpose is different.

1. Identity authentication.

The purpose of authentication is to confirm that the user who is currently claiming to be an identity is indeed the claimed user.

2. Digital signature.

Digital signature is an application of asymmetric key cryptography and digital digest technology to identify digital information.

Third, the methods are different.

1. Identity authentication.

There are many methods of authentication, which can be basically divided into: shared key-based authentication, biological-based authentication, and public-key encryption algorithm-based authentication. Different authentication methods have different levels of security.

2. Digital signature.

The digital signature algorithm relies on public-key cryptography to implement. In public-key cryptography, each user has a pair of keys: a public key and a private key.

Public keys can be freely issued, but private keys are kept secret, and the requirement is that it is impossible to deduce the private key from the public key.

The common digital signature algorithm includes three algorithms:

Password generation algorithms.

Labeling algorithms. Verify the algorithm.

Digital signature: an encryption algorithm that is open to the algorithm and the private key is kept secret, which can determine the identity of the author;

Identity authentication: It usually refers to the authentication method based on a third-party certification body, and a trusted third-party organization provides authentication services.

A digital signature is a form of electronic signature and is a subset of electronic signatures.

An electronic signature means data that exists in electronic form in any data message to identify the signer and to indicate that the signer identifies its contents; Electronic signatures in the narrow sense are digital signatures that use the PKI system.

A digital certificate is a type of network digital identity certificate issued and managed by a third-party certification authority (CA).