| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an operating device for a mask generating function capable of operating at high speed with a small operation amount, and a program for the same and a recording medium for the same. <P>SOLUTION: The seed C of a random number and a desired output length TLen are input (S1). The number of times N of hash operation is obtained by [TLen/Dlen], and the number of times M of repeating block (element) hash operation in each hash operation is obtained by [Clen+4+4+1+8/BLen] (CLen is the length of C; 4 is the length of an encoding part I2OSP(n, 4); 1 is the padding length; 8 is the length of encoded C; [A] is the smallest integer equal to or larger than A). An "n" is initialized into N-1, which can be used in the next operation of n-1. That is, common operation parts whose input/output are equal are calculated (S4); each operation of the parts is performed; the result of the operation is stored (S6) as an operation intermediate value in a storage section; each operation of non-common operation parts is performed by inputting also the operation intermediate value; the result h(n) of each hash operation is stored (S7); the same procedure is repeated by subtracting 1 from n; and every h(n) is linked under n=0 and output. <P>COPYRIGHT: (C)2007,JPO&INPIT |
