Fault Tolerant Key Generation and Secure Spread Spectrum Communication
This study presents a secure information transmission system compromised of two main parts. The first component makes use of the principle of reciprocity in frequency-selective wireless channels to derive a pair of keys for two legitimate parties. The proposed key generation algorithm allows for two asynchronous transceivers to derive a pair of similar keys. Moreover, we apply a unique augmentation - called strongest path cancellation (SPC) - to the keys and have validated through simulation and real-world measurements that this technique significantly boosts the security level of the overall design. In the second part of the secure information transmission system, we introduce the concept of artificial noise to multi-carrier spread-spectrum (MC-SS) systems. The keys generated in the first part are used as spreading code sequences for MC-SS and artificial noise is added to further enhance the security of this communication setup. Two different attacks on our proposed system are evaluated. First, a passive adversary who follows the exact same steps as the legitimate users to detect confidential information is considered. In the second attack, we evaluate the design in presence of an adversary with significant blind detection capabilities.