Secret Key Generation Based on Channel State Information in a mmWave Communication System

Inhalt:
Secret key generation by exploiting the wireless channel traits of the PHY layer has been a popular theoretical research topic in recent years. In this paper we show a practical implementation of this idea, including the algorithmic approaches of the constituent steps in the generation process. We use the channel state information (CSI) of a static 60 GHz OFDM wireless system as a source of randomness necessary for our key extraction. By exploiting the CSI from multiple subcarriers, we achieve a bit generation rate of up to 16 Kbits per second. Test results from both simulated and measured channel data show that our extracted keys with a length of 160-256 bits have a high entropy and pass all of the NIST tests suitable for the key length.