Reference Work Entry

Encyclopedia of Cryptography and Security

pp 682-683

Key Generation Using Physical Properties of Wireless Communication

  • Aggelos KiayiasAffiliated withDepartment of Computer Science Engineering, University of Connecticut
  • , Bulent YenerAffiliated withDepartment of Computer Science, Rensselaer Polytechnic Institute


A key exchange protocol between two parties that enables the calculation of a key on both sides while preventing an adversary to extract any nontrivial information about the key. The protocol assumes the parties have access to a correlated random source that is derived from the wireless communication link they employ. The adversary can be considered to be passive (eavesdropping) or active (modifying the communication environment).


In a wireless environment, the received signal suffers from external distortions that include mean propagation pathloss, fading, interference from other users’ signals, and thermal noise. Among these causes, fading may change in an unpredictable way as the wireless environment changes due to the frequency, location, direction, and reflecting coefficients of the surrounding objects. The unpredictability of these factors presents a wireless channel as a (nonstationary) stochastic process that may contain a substantial amou ...

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