SSL Encryption Mechanism

A.

SSL (Secure Sockets Layer) uses symmetric encryption to provide confidentiality of user data.

Symmetric encryption is a type of encryption in which the same key is used for both encryption and decryption of the data. In SSL, the symmetric encryption key is generated randomly for each session and is negotiated between the client and server using the SSL Handshake protocol.

During the SSL Handshake protocol, the client and server agree on a common encryption algorithm and a symmetric encryption key. The client encrypts the symmetric encryption key using the server's public key, which is obtained from the server's SSL certificate, and sends it to the server. The server decrypts the symmetric encryption key using its private key, which is stored securely on the server, and then both the client and server use the symmetric encryption key to encrypt and decrypt all data exchanged during the SSL session.

Symmetric encryption is fast and efficient compared to asymmetric encryption, which uses two different keys for encryption and decryption. Asymmetric encryption is used in SSL to provide the authentication of the server and client and to establish the initial SSL session key. RSA public-key encryption and Diffie-Hellman exchange are both examples of asymmetric encryption algorithms used in SSL.

In summary, SSL uses symmetric encryption to provide confidentiality of user data, which is negotiated between the client and server during the SSL Handshake protocol. Asymmetric encryption is used for authentication and to establish the initial SSL session key.