An Adaptive Idle-Wait Countermeasure Against Timing Attacks on Public-Key Cryptosystems

Successful timing attacks against public-key cryptosystems have been demonstrated in many forms, suggesting the use of a technique known as blinding as countermeasure to these attacks. An alternative countermeasure has been considered, though somewhat overlooked and less studied in existing literature, consisting of idle-wait to make the decryption time independent of the data. In this work, we propose and implement an optimized form of this countermeasure, making the idle-wait adaptive, with the goal of minimizing the performance penalty. We present both analytical and experimental results of simulations designed to evaluate our method’s performance and effectiveness, and compare it against alternative countermeasures.