公开(公告)号：JPH1063183A

公开(公告)日：1998-03-06

申请号：JP12452497

申请日：1997-05-14

Applicant: KOREA ELECTRONICS TELECOMM ,  KOREA TELECOMMUN AUTHORITY

Inventor： JIYANUON RII ,  HIYUNSUUKU CHIYOO ,  JIYONSEOOKU CHIYAE ,  KIYOON HO

IPC: G09C1/00 ,  H04B1/38 ,  H04H20/00 ,  H04L9/06 ,  H04N21/2347 ,  H04N21/266 ,  H04H1/00 ,  H04N7/16

Abstract: PROBLEM TO BE SOLVED: To make a data encryption method not inferior in terms of execution speed as well while maintaining high safety and confidentiality, by adding a byte shift function and dynamic allocation transform scheme to conventional data encryption standard algorithm. SOLUTION: The bit shift function(BSF) is executed before a right side block (32 bit)) is applied to the next round to deal with a linear cryptoanalysis. Namely, the bit shift function(BSF) is a method for comparing the input and output of an S box, analyzing the correlative relation thereof and determining a linear approximation equation relating to the nonlinear S box. The input of the bit shift function(BSF) is shifted by using a module path as an element for dealing with relating to the linear cryptoanalysis method. The dynamic allocation transform (DATA) is executed by using the round key (Ki) formed in order to intensify the function of an (f) function after the bit shift function(BSF) is executed. The confidentiality of the data is improved by proving the method with the element relating to differential cryptoanalysis.