Patent ID: 7333611

Claim:
A method for achieving data encryption and/or key expansion/generation, said method comprising the steps of: providing a short, shared, secret, seed key between first and second parties, the seed key allowing the first and second parties to encrypt and decrypt messages transmitted between the first and second parties; extending the seed key to a long extended key; segmenting the extended key into disjointed blocks of running keys, using the running keys derived from the extended key to choose one of many possible quantum or classical signal sets embodied in a number of modes of electromagnetic or acoustic or other physical origins; adjusting the signal strength of each signal in the signal sets in accordance with the number of signal sets to obtain a desired security level, wherein quantum or classical noise in the system owing to use of at least 10 photons hides both encrypted data bits and the running key preventing a third eavesdropping party from success in compromising message transmissions between the first and second parties, and wherein the number of bases M for the signal coherent states is larger than the average number of photons |{acute over (α)} 0 | used to encode a given bit value.