Key-Reuse Vulnerability of Phase-Keyed Fourier-Curve Modulation: Relation Leakage and Key-Refresh Cost on Coded Links
The study shows that reusing a phase key in Fourier-curve modulation leaks information about secret characters through harmonic relations. A non-data-aided attack can recover keys without enumerating the entire key space, proving that nominal key size and error rates are insufficient security guarantees for such keyed modulations.