SSL security mechanism

Secure connections provided by SSL have these features:

• Confidentiality—SSL uses a symmetric encryption algorithm to encrypt data and uses the asymmetric key algorithm of RSA to encrypt the key to be used by the symmetric encryption algorithm.

• Authentication—SSL supports certificate-based identity authentication of the server and client by using the digital signatures. The SSL server and client obtain certificates from a CA through the PKI.

• Reliability—SSL uses the key-based message authentication code (MAC) to verify message integrity. A MAC algorithm transforms a message of any length to a fixed-length message. With the key, the sender uses the MAC algorithm to compute the MAC value of a message. Then, the sender appends the MAC value to the message and sends the result to the receiver. The receiver uses the same key and MAC algorithm to compute the MAC value of the received message, and compares the locally computed MAC value with that received. If the two values match, the receiver considers the message intact. Otherwise, the receiver considers that the message has been tampered with in transit and discards the message.

For more information about symmetric key algorithms, asymmetric key algorithm RSA and digital signature, see "Managing public keys."

For more information about PKI, certificate, and CA, see "Configuring PKI."