Patent ID: 7835546

Claim:
A pseudorandom number generation apparatus comprising: an imaging element configured to output a plurality of image signals equivalent to imaging light reflecting a target of identification, said target of identification being inside a certain part of a living body, the plurality of image signals including a first image signal, a second image signal, a third image signal, and a fourth image signal; an extractor configured to: (a) generate a first difference between the first image signal and the second image signal; (b) generate a second difference between the third image signal and the fourth image signal; and (c) calculate a degree of difference between: (i) said generated first difference between the first image signal and the second image signal; and (ii) said generated second difference between the third image signal and the fourth image signal, said calculated degree of difference reflecting a change arising from said living body and a change of said imaging element; and a generator configured to generate a pseudorandom number using the calculated degree of difference as a seed, said calculated degree of difference being calculated by said extractor, said generated pseudorandom number being supplied to a cryptographic unit configured to encrypt transmission data using said generated pseudorandom number.