Patent attributes
Techniques to bolster the security of an AlphaEta cryptosystem using spectral phase encoding. In one aspect, a spatial light modulator (SLM) is used to change the spectral code (spectral phase) of each optical bit in response to the output of an extended key generator based on a cryptographic algorithm. In other aspects, additional time and polarization modulations are used to maintain high security levels as well as good performance levels. Such methods are combined with traditional key generation methods such as key-distribution centers or one-way mathematical algorithms to bolster the security of traditional key generation as well.