Title:
ILLEGAL ALTERATION PREVENTION SYSTEM FOR DATA OR THE LIKE AND ENCIPHERING DEVICE USED WITH THE SYSTEM
Document Type and Number:
Japanese Patent JP3481470
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To provide a technique that prevents an illegal user from altering software and data and illegally attempting to use them.
SOLUTION: An encipher program storing means 112 stores enciphered program codes while being divided into plural blocks. A cryptographic key calculating means 102 uses a one-way function (hash function, etc.), of a program code currently existing on a main storage and calculates a cryptographic key for performing cipher release of an enciphered program code stored in the means 112 to be next executed. When the program code is partially altered to illegally use software, a correct cryptographic key can not be obtained and the execution of the program stops.
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Inventors:
Takuya Morishita
Application Number:
JP29708198A
Publication Date:
December 22, 2003
Filing Date:
October 19, 1998
Export Citation:
Assignee:
NEC
International Classes:
G06F12/14; G06F9/06; G06F21/10; G06F21/12; G06F21/60; G06F21/62; G09C1/00; H04L9/10; H04L9/34; (IPC1-7): G06F9/06; G06F12/14; G09C1/00
Domestic Patent References:
| JP5217033A | ||||
| JP9230786A |
Attorney, Agent or Firm:
Masahiko Desk (2 outside)