公开(公告)号：JPH0619392A

公开(公告)日：1994-01-28

申请号：JP16707991

申请日：1991-07-08

Applicant: IBM

Inventor： RUSHINA RIINIEN GURIIN ,  MAIKERU JIEEMUZU KERII ,  RONARUDO MOOTON SUMISU ,  JIYURIAN TOOMASU ,  FUIRU CHIICHIYUN IEE

IPC: G09C1/00 ,  G06F12/14 ,  H04L9/08 ,  H04L9/06 ,  H04L9/14

Abstract: PURPOSE: To dynamically change the cryptographic master key of a system without stopping the system or spoiling the integrity of cipher processing operation that is being executed. CONSTITUTION: A cipher processing mechanism 102 and a cipher processing support program 111 are used. Individual master keys are given characteristic version numbers. When an inputted master key is used as a new current master key, the current master key used so far is changed into an old master key. When it is found from a version number attached to a received cipher processing request that the key used for the received request is a key ciphered with the old master key, the key is reciphered and converted from the key ciphered with the old master key into a key ciphered with the current master key, and the converted key is used thereafter.