This action provides confidentiality because only the receiving party is able to do the initial decryption of the message using their private key. The receiver uses the sender's public key to further decrypt the encrypted message. Because only the sender has access to their private key, the receiver is assured that the encrypted message originated from the sender. A message digest is used to verify that neither party or a third party has tampered with or changed the message in any way. Changing even one bit in the message will change the length of the signature and thus prove that the message has been tampered with.
Digital certificates make it possible to trust an entity on the Internet.
A digital certificate contains the user's credentials, which have been verified by a neutral third-party certificate authority. A second key is used to decrypt the data, using a complementary algorithm and a related value. The two keys must contain a related value and are known as a key pair . SSLv3 was adopted in 1994. The major difference between versions 2 and 3 is the addition of the extensions field.