Method and apparatus for secure transmissions. Each user is provided a
registration key. A long-time updated broadcast key is encrypted using
the registration key and provided periodically to a user. A short-time
updated key is encrypted using the broadcast key and provided
periodically to a user. Broadcasts are then encrypted using the
short-time key, wherein the user decrypts the broadcast message using the
short-time key. One embodiment provides link layer content encryption.
Another embodiment provides end-to-end encryption.