At&t Mobility II LLC

Jeffrey Tedeschi

Eric Klingler

Disclosed embodiments include a method for synchronizing a cryptosystem. In one embodiment, the method uses existing control data that is transmitted as part of a connection establishment process in a wireless communication system. In one embodiment, messages that are normally sent between a base station and a remote unit during the setup of both originating and terminating calls are parsed to detect a particular control message that indicates the start of telephony data transmission. Detection of this message indicates a point at which encryption/decryption can begin, and is used to synchronize the cryptosystem. Synchronizing a cryptosystem involves generating an RC4 state space in a keyed-autokey ('KEK') encryption system. In one embodiment, Lower Medium Access Channel ('LMAC') messages are used according to a wireless communication protocol. This is convenient because the LMAC messages are passed through the same Associated Control Channel (&#x201c;ACC&#x201d;) processing that encrypts and decrypts the telephony data.

Growing community of inventors

Woodinville, WA, United States of America

Jeffrey Tedeschi