Patent ID: 7317794
Filing Date: 2008-01-08
Classification: H04L

Abstract:
1. An enciphering and deciphering apparatus which, in a mathematic system in which modulo n of the positive integer is present, when an optional positive integer X k =X k1 for satisfying an equation X k =X k−1 +1(1<=k<=n−1, X 0 =0) constitutes a first expression, based on said first expression X k1 , seeks a second expression Y k1 defined by an equation Y k1 =X k1 m (where m is a positive integer), said apparatus comprising: an input terminal for the input of said integers n and m and a plurality of first expressions; a coefficient memory unit for storing binomial coefficients an arithmetic operating unit which, based on an equation X an output terminal for an output of said second expression Y wherein said arithmetic operating unit further comprises a power raising value memory unit for storing a group of power raising values X a coefficient selector for selecting one or more binomial coefficients required for computing a power raising value X a multiplier for seeking a product of said binomial coefficients selected by said coefficient selector and one or more power raising values X an adder for seeking a sum of one or more products acquired by said multiplier and a numerical value “1”; a latching unit for latching said sum acquired by said adder as a power raising value X a controlling unit which, by way of controlling operations of said coefficient selector, said multiplier, said adder, said latching unit, and said power raising value memory unit, serially computes a plurality of power raising values X wherein said enciphering and deciphering apparatus is used for enciphering and/or deciphering RSA ciphers.