Mobility

Secret Key Extraction From Wireless Signal Strength in Real Environments

Date Added: Mar 2012
Format: PDF

The authors evaluate the effectiveness of secret key extraction, for private communication between two wireless devices, from the Received Signal Strength (RSS) variations on the wireless channel between the two devices. They use real world measurements of RSS in a variety of environments and settings. The results from their experiments with 802.11 based laptops show that in certain environments, due to lack of variations in the wireless channel, the extracted bits have very low entropy making these bits unsuitable for a secret key, an adversary can cause predictable key generation in these static environments, and in dynamic scenarios where the two devices are mobile, and/or where there is a significant movement in the environment, high entropy bits are obtained fairly quickly.