Synchronization of encryption in a wireless communication system
US7436964B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 19, 2001 |
| Grant date | Oct 14, 2008 |
| Priority date | — |
| Expiry date | Sep 18, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04W56/00
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
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 (“ACC”) processing that encrypts and decrypts the telephony data.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.