Digital signature method using RSA public-key cryptographic based on CRT and apparatus therefor

摘要

PURPOSE: A method and an apparatus for digital signature using a CRT(Chinese Remainder Theorem)-based RSA(Rivest, Shamir, and Adleman) public key encoding method are provided to reduce the amount of calculation by using a compatible structure with an existing system without adding new parameters. CONSTITUTION: A value of Sp is obtained from a mathematical expression of Sp=M¬dp mod p(104). A value of Sq is obtained from the mathematical expression of Sq=M¬dq mod q(105). A value of T as an authentication value is obtained from the mathematical expression of T=T1+T2(108). A value of S1 is obtained from the mathematical expression of S1=((q+T)q¬-1 mode p)Sp(109). A value of S2 is obtained from the mathematical expression of S2=((p+T)p¬-1 mode q)Sq(110). A value of S as a signature value is obtained from the mathematical expression of S=S1+S2 mode n(111).