Encrypting apparatus

Abstract

An encrypting apparatus wherein the alignment of consumed-current waveforms is made more different, thereby enhancing a function of preventing a cryptographic key from being decrypted by a consumed-current analysis. There are included a clock control circuit (3) that is so connected as to receive a clock signal (CLK) and a pseudo random number and subjects, based on the pseudo random number, the clock signal (CLK) to a suspending process and a resuming process to generate an encryption processor clock signal (CCLK); an encryption processor (2) that subjects data, which is to be encrypted, to an encrypting process in synchronization with the encryption processor clock signal; and a current control circuit (4) that acquires an arithmetic state (S) indicative of an operational state of the encryption processor (2) and adjusts the consumed-current amount in accordance with the arithmetic state (S).

Description

technical field [0001] The present invention relates to an encryption device in which a function of preventing key decryption by current consumption analysis is improved. Background technique [0002] Today, with the continuous advancement of networking, information has become of great value. Along with this, information security has also become of great significance. Among them, the "cryptography technology" for the purpose of concealing information is positioned as a core technology among many security technologies. [0003] The so-called cipher refers to a special symbol, character, or its order and method determined in such a way that the content cannot be specified by persons other than the parties concerned, and it is composed of the original text that the sender wishes to send. A text (ordinary text) is converted (encrypted) into a cipher text and sent, and the receiver who receives the cipher text converts (decrypts) it into the original text again to recognize its ...

AI Technical Summary

Problems solved by technology

However, in the case of using the method described in Patent Document 1 below, since a structure in which noise current is superimposed synchronously with the master clock signal which becomes the timing of the operation of the encryption processing circuit is adopted, for example, in the case of using the same key and a general article When multiple encryption operations are performed, the current consumption varies randomly, but the operation time is fixed, so calibration is easy

In addition, when the current consumption is repeatedly measured using the same key and common text, by averaging these current consumption waveforms, there is a possibility that only random noise current components will be removed, and it is conceivable as a method of current consumption analysis. Countermeasures may not function sufficiently

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