Everlasting secrecy in wireless communications: Challenges and approaches

A guarantee of everlasting secrecy is of great interest in modern communication systems. Information-theoretic secrecy is a promising method for providing such and has been widely considered. However, the adoption of information-theoretic security has been hampered by the difficulty of guaranteeing the necessary conditions for secrecy to be realized in a wireless communications environment, where the adversary might have a significant (and likely unknown) signal-to-noise ratio (SNR) advantage over the intended recipient. Thus, whereas the wireless communications environment provides opportunities to gain an advantage over the adversary, as has been considered widely in the literature, it is that same environment that challenges its ultimate utility. We review pertinent past and emerging work to address these challenges and provide perspectives on future directions in the field.