Abstract: An obfuscating apparatus creates a table for inputting the same number of arguments for multiplying and squaring operations, and sets the output values of the table so that the outputs may depend on the arguments. With regard to the squaring operations, there are added and tabulated adding operations using the arguments necessary only for the multiplications, so that the number of arguments is equal to that of the multiplication operations. The outputs depend on all the arguments, so that the presence or absence of the added arguments is unknown unlike the case in which dummy arguments that are not processed are added.

Abstract: A program obfuscating device for generating obfuscated program from which unauthorized analyzer cannot obtain confidential information easily.

Abstract: A signature generation apparatus is capable of making a value used in signature generation processing difficult to analyze. In the signature generation apparatus, a random number generation module generates a len-bit random number u, a selection module converts the generated random number u into a bit expression, and acquires element pairs corresponding to the bit values from a table memory unit. A random element generation module applies a basic operation of a first group G and a second group to all acquired element pairs, and calculates an element Pk on the first group G and an element Pak on the second group Ga. The signature generation apparatus generates a digital signature S for a message m with use of a transformation module, a main operation module, an inverse transformation module, a multiplication module, a division module, and a signature data generation module.

Abstract: Provided is an obfuscating apparatus for making a program analysis more difficult. The obfuscating apparatus creates a table for inputting the same number of arguments, for multiplying and squaring operations, and sets the output values of the table so that the outputs may depend on those arguments. To the squaring operations, more specifically, there are added and tabulated the adding operations using the arguments necessary only for the multiplications, so that the number of arguments is equalized to that of the multiplications. In this case, moreover, the outputs depend on all the arguments, so that the presence/absence of the added argument is unknown unlike the case, in which dummy arguments not to be actually processed are added.

Abstract: Provided is a program conversion apparatus for generating a secret holding program, which disables a malicious analyzer from analyzing the an original program easily.

Abstract: A signature generation apparatus is capable of making a value used in signature generation processing difficult to analyze. In the signature generation apparatus, a random number generation module generates a len-bit random number u, a selection module converts the generated random number u into a bit expression, and acquires element pairs corresponding to the bit values from a table memory unit. A random element generation module applies a basic operation of a first group G and a second group to all acquired element pairs, and calculates an element Pk on the first group G and an element Pak on the second group Ga. The signature generation apparatus generates a digital signature S for a message m with use of a transformation module, a main operation module, an inverse transformation module, a multiplication module, a division module, and a signature data generation module.

Abstract: A program obfuscating device for generating obfuscated program from which unauthorized analyzer cannot obtain confidential information easily.

Abstract: A computer system that makes it difficult to analyze the content of a calculation. In the computer system, a power operation unit performs the following operations using the input data “a” and “b”: ga=ga mod n, gb=gb mod n. Next, in the computer system, a multiplication unit performs the following calculation using ga and gb: gab=ga×gb mod n. Next, in the computer system, a discrete logarithm calculation unit calculates ci mod pi?1 to satisfy gab=gci mod pi (i=1, 2, 3, . . . , k). Next, in the computer system, a CRT unit calculates “c” to satisfy ci=c mod pi?1 (i=1, 2, 3, . . . , k) using the Chinese remainder theorem CRT.

Abstract: A computer system that makes it difficult to analyze the content of a calculation. A power operation unit (262) performs the following operations using the input data “a” and “b”: ga=ga mod n, gb=gb mod n. Next, a multiplication unit (264) performs the following calculation using ga and gb: gab=ga×gb mod n. Next, a discrete logarithm calculation unit (266) calculates ci mod pi?1 to satisfy gab=gci mod pi (i=1, 2, 3, . . . ,k). Next, a CRT unit (267) calculates “c” to satisfy ci=c mod pi?1 (i=1, 2, 3, . . . ,k) using the Chinese remainder theorem CRT.

Abstract: An apparatus utilizing sound-image localization for distributing/sharing audio secret information is provided, the apparatus comprises: a first signal processor for distributing/sharing at lest one target sound as secret information into a plurality of stereo media, wherein the distribution is performed such that the sound-image of the target is shifted from the center position of the head when said plurality of stereo media are simultaneously played to be heard in a binaural manner; a second signal processor for distributing a plurality of decoy sounds as disturbing information into the said plurality of stereo media, wherein the distribution is performed such that the sound-image of the decoy sounds is localized to the center position of the head when said plurality of stereo media are simultaneously played to be heard in a binaural manner.

Abstract: When a secret is encrypted and stored, it is necessary to provide a countermeasure for the situation where a key is lost (key recovery system). In the present invention, a key recovery system for an enveloped data format in which a common key is used to encrypt a plaintext (secret) and a user's public key is used to encrypt the common key and attached to an encrypted text is provided. In the present invention, only the common key is decrypted to recover the secret without reconstruction of split secret keys kept in a plurality of key storage apparatuses.