encrypted transmission process

Encrypted transmission

symmetric encryption algorithm [HTTP]

Asymmetric encryption algorithm [HTTPS]

A to B
A encrypts with B's public key.In the past, only B's private key can be solved.A and B will not give the private key to the other party.
Problem situation:
A sends it with its own public key, and connects its public key with the information to send it.b can be solved with a public key.
But if there is a c, it can use the public key of a in the information if it has obtained this information, then the mutual information will be exposed.
Solution
Combined with the symmetric encryption algorithm, when the asymmetric encryption algorithm is used, the message carries a symmetric encryption key algorithm.Then ab has this unique symmetric encryption algorithm key, and c does not know.This can be efficient and safe

In order to prevent the transmission of public key information from being replaced by a third party: CA certificate
The CA certificate is used to prevent the public key from being intercepted during the transmission of the public key.Encrypt once.In this way, the public key received by the recipient must be unlocked with the private key of the CA certificate and then used.This prevents tampering in the transmission of public key information.

Digital Signature and Encryption

Digital signature: private key encryption public key decryption
Encryption: public key encryption private key decryption