EM alignment using phase for secure embedded systems

If electromagnetic (EM) waves emanating from a wireless device during a cryptographic computation leak sufficient information, it may be possible for an attacker to reconstruct the secret key. Despite the complexities of a Java-based PDA device, this paper presents a new phase based technique for aligning EM frames for subsequent time based DEMA. The proposed technique involves: fast Fourier transform, phase-substitution, inverse fast Fourier transform and time based DEMA. Results are repeatable over several different secret keys. Unlike previous research the new technique does not require perfect alignment of EM frames, and demonstrates robustness in the presence of a complex embedded system (including cache misses, operating system events, etc.) with random delays as well as random operations. This research is important for future wireless and complex embedded systems where security is crucial.