Error reconciliation with turbo codes for secret key generation in vehicular ad hoc networks

We present an algorithm that allows two users to establish a symmetric cryptographic key by incorporating the most important features of the wireless channel in vehicle-to-vehicle (V2V) communication. The proposed model includes surrounding scatterers’ mobility by considering other vehicles; it also includes three-dimensional (3D) multipath propagation. These temporal variability attributes are incorporated into the key generation process where non-reciprocity compensation is combined with turbo codes (TCs). For fair comparisons, the indexing technique is applied in conjunction with the non-reciprocity compensation technique. A series of simulations are run to calculate key performance indicators (KPIs). The entropy values were high throughout all rounds of simulation and estimated around 0.94 to 0.99 bits per sample. Furthermore, simulation results reveal a decrease in bit mismatch rate (BMR) and an increase key generation rate (KGR) when TCs are used. The estimated BMR is nearly the same for different key lengths, and it is estimated to only 0.02 with TCs, compared to 0.22 obtained with the indexing technique. Finally, the key generation rate was also reported high ranging from 35 to 39 for the 128-bit symmetric keys per minute with TCs, while it is ranging from 3 to 7 when compared with a sample indexing technique published in the public domain.