Transformation pattern generating device and encryption function device

Claim 1

An encryption function device, comprising: key input means for inputting a key for encryption; transformation pattern generating means for using the key as a key number sequence and for generating a transformation pattern using at least one of the key number sequence and a pseudo-random number sequence generated by a random number generator using the key number sequence as a seed; and transformation means for transforming data in accordance with the transformation pattern generated by said transformation pattern generating means, wherein the transformation pattern includes m substitution tables and a permutation circuit having m input terminals and m output terminals, wherein said transformation means includes: m input switches, where m is an even number; m output destination switches; m exclusive-OR circuits; and a bit rotate shift mechanism having m input terminals and m output terminals; and wherein a j-th input switch in one switching state outputs a j-th mini-block which is one of m mini-blocks into which input data is divided, and the j-th input switch in another switching state outputs a mini-block sent from a j-th output destination switch; the j-th output destination switch in one switching state outputs the j-th mini-block of the bit rotate shift means, and the j-th output destination switch in another switching state outputs the j-th mini-block of the bit rotate shift means to the j-th input switch; an output of a k-th input switch is input to an address of a k-th substitution table, where k is between 1 and m/2; an output of the k-th substitution table and an output of an (i+k-1)-th substitution table are input to a k-th exclusive-OR-circuit; an output of an (i+k-1)-th exclusive-OR circuit is input to an address of the (i+k-1)-th substitution table; an output of an (i+k-1)-th input switch and the output of the k-th substitution table are input to the (i+k-1)-th exclusive-OR circuit; an output of the k-th exclusive-OR circuit is input to a k-th input terminal of the permutation circuit; the output of the (i+k-1)-th substitution table is applied to an (i+k-1)-th input terminal of the permutation circuit; a j-th output of the permutation circuit is input to a j-th input terminal of the bit rotation shift means; and the bit rotate shift means rotatively shifts entire data input to first to m-th input terminals.