US 2015/0039900 A1Published application

Program execution method and decryption apparatus

AssigneeFujitsu Semiconductor Limited

InventorTatsuro KAWAKAMI

Life of this patent

Estimating the term…

Loading patent…

Abstract

A method for program execution in a system including a decryption apparatus that prevents external referencing and an information processing apparatus communicating therewith and accessing first and third storage areas, includes: the decryption apparatus detecting a series of commands from a command group obtained by decrypting at least a portion of a program stored in the first storage area; obfuscating and storing the series of commands to a second storage area storing the decrypted portion and within the first storage area; assigning, when an execution request is received from the information processing apparatus, the third storage area having a capacity equivalent to any one series of commands; and storing to the third storage area, a series of certain commands stored in the second area and obtained by canceling obfuscation of the commands that correspond to the execution request; and the information processing unit executing the series of certain commands.

Claims18

Dependent claims

A method for executing a program in a system that includes a decryption apparatus having a structure that prevents external referencing of information stored therein and an information processing apparatus configured to communicate with the decryption apparatus, the method comprising:

detecting, by the decryption apparatus, a series of commands from a command group obtained by decrypting at least a portion of an encrypted program stored in a first storage area, the first storage area being configured to be accessed by the information processing apparatus;
storing, by the decryption apparatus, obfuscated commands to a second storage area that stores a decrypted portion of the encrypted program and is within the first storage area, the obfuscated commands being obtained by obfuscating the detected series of commands;
assigning, by the decryption apparatus, when a first execution request of any one series of commands in the command group is received from the information processing apparatus, a third storage area that is different from the first storage area, the third storage area being configured to be accessed by the information processing apparatus and having a storage amount equivalent to the any one series of commands;
storing, by the decryption apparatus, to the assigned third storage area, a series of certain commands stored in the second area, the series of certain commands being obtained by canceling obfuscation of the obfuscated commands that correspond to the first execution request;
and
executing, by the information processing unit, the series of the certain commands stored in the third storage area.

3 more elements

A decryption apparatus configured to communicate with an information processing apparatus and having a structure that prevents external referencing of information stored therein, the apparatus comprising

a processor configured to:
detect a series of commands from a command group obtained by decrypting at least a portion of an encrypted program stored in a first storage area, the first storage area being configured to be accessed by the information processing apparatus;
store obfuscated commands to a second storage area that stores a decrypted portion of the encrypted program and is within the first storage area, the obfuscated commands being obtained by obfuscating the detected series of commands;
assign, when a first execution request of any one series of commands in the command group is received from the information processing apparatus, a third storage area that is different from the first storage area, the third storage area being configured to be accessed by the information processing apparatus and having a storage amount equivalent to the any one series of commands;
and
store to the assigned third storage area, a series of certain commands stored in the second area, the series of certain commands being obtained by canceling obfuscation of the obfuscated commands that correspond to the first execution request.

3 more elements

Dependencies are inferred from the claim text.