Patent ID: 8374351
Filing Date: 2013-02-12
Classification: G06F,H04L

Abstract:
1. An encryption device including a generator which generates a pseudo-random number sequence based on a secret key and applies the pseudo-random number sequence to a plain text so as to generate an encrypted text, the generator comprising: a section that uses an internal state in accordance with a state based on a permutation of a sequence of a finite number of numeric values, as an internal state used for generation of the pseudo-random number sequence, and executes a predetermined leftward or rightward rotate shift, depending on a number smaller than an internal state number, based on the result of a linear operation or a non-linear operation, or a combination of a linear operation and a non-linear operation using one or more numeric values of the internal state, and sets at least one temporary variable used for generation of the pseudo-random number sequence to be a temporary variable having as a value a result of the execution of the predetermined leftward or rightward rotate shift, and a section that generates the pseudo-random number by a predetermined prescribed operation on one or a plurality of numeric values of the internal state and the temporary variable.