Side channel analysis attacks against channel state information based key generation

Abstract

The recent research on randomness of wireless channels shows that the channel state information (CSI) can be harnessed to generate secret keys for wireless communications. This CSI-based key generation claims to be secure due to the spatial independence between the legitimate channel and the eavesdropping channel. However, this paper presents the discovery that the side-channel information about the security key may leak from the electronic instruments when they are measuring the CSI, when the instruments are encrypting/decrypting for key confirmation, or even when the device is communicating with the established key. Through analyzing the side-channel information, the secret keys can be extracted. The side-channel information could be obtained without approaching the legitimate transceiver, thus posing a serious threat to the CSI-based key generation.Index Terms-Channel state information (CSI), secret key, side-channel analysis.

Channel-Based Key Generation for Encrypted Body-Worn Wireless Sensor Networks

“…Encryption by means of the generated key can be performed employing a number of algorithms suitable for execution on a low-power micro controller [ 13 ]. Keys generated following this approach can be constantly updated and hence should be virtually impossible to break, provided that careful hardware construction of the sensor node makes side-channel attacks (by measuring other electrical parameters such as power supply current) impossible [ 14 ]. Emissions by the processor should be minimized, as advanced side-channel attacks are possible with very low cost Software Defined Radios (SDR) [ 15 ].…”