Topic Last Modified: 2011-05-02
A key is a secret code or number that is used to encrypt, decrypt, or validate secret information. There are two sensitive keys in use in public key infrastructure (PKI) that must be considered: the private key that each certificate holder has and the session key that is used after a successful identification and session key exchange by the communicating partners. A compromised-key attack occurs when the attacker determines the private key or the session key. When the attacker is successful in determining the key, the attacker can use the key to decrypt encrypted data without the knowledge of the sender.
Lync Server 2010 uses the PKI features in Windows Server 2008 operating system and Windows Server 2008 R2 operating system to protect the key data used for encryption for the Transport Layer Security (TLS) connections. The keys used for media encryptions are exchanged over TLS connections.