摘要:
The cloning source of an authorized receiving device cannot be identified. A key distribution system 1 concerning the present invention includes: a communication channel 10; a key distribution center 11; a server 12; and receiving devices 13a to 13n. The key distribution center 11 distributes, to the server 12, the information necessary for distributing shared keys SK to the receiving devices 13a to 13n, and distributes the individual information group EMMG necessary for receiving the shared keys SK from the server 12. The server 12 generates the shared keys SK, generates the common information ECM based on the shared keys SK and the system secret variable group set SPGS, and distributes the common information ECM to the receiving devices 13a to 13n. The receiving devices 13a to 13n obtain the shared keys SK based on the individual information group EMMG and the common information ECM and outputs them to outside.
摘要:
A signature generation apparatus and a signature verification which can surely prevent occurrence of inappropriate signature verification error are providedA signature generation apparatus (110) includes a signature generation unit (114) which calculates a signature vector (s, t) for a message m using a private key, and generates signature data S indicating polynomials sl and sh that can specify the polynomial s and a polynomial th which is a quotient when the polynomial t is divided by q.
摘要:
A transmission device including: copy unit that extracts part or all of partial contents, as tracking information, from a content, and copies the extracted tracking information, thereby generating pieces of tracking information; candidate information obtaining unit that obtains pieces of candidate information respectively corresponding to the pieces of tracking information; evidence information obtaining unit that obtains evidence information generated dependently on a piece of candidate information selected by the reception device from among the pieces of candidate information; hash generating unit that generates hash values respectively in accordance with the pieces of candidate information; embed unit that embeds the hash values respectively into the pieces of tracking information, and embeds the evidence information into each piece of tracking information; and transmit unit that transmits each piece of tracking information in which a hash value and the evidence information have been embedded.
摘要:
An encrypted communication system, capable of performing processing with the speed higher than the conventionally achieved speed, has an encryption device and a decryption device which share parameters that satisfy p=3 and q=2ˆk (k: an integer of 2 or greater) (S161), where the decryption device generates a public key and a private key using the parameters (S162-S165), the encryption device encrypts a plain text using the public key (S166-S170), and then, the decryption device decrypts the encrypted text using its own private key (S171-S173).
摘要:
A content recording/reproducing system, which records and reproduces a sub-content relating to a main content, includes a distribution device, first and second recording media, a recording device and a reproducing device. The first recording medium that is non-rewritable prestores key data based on which a public key is derivable, and the main content. The distribution device outputs verification information that includes the sub-content and is generated by applying a digital signature to relative information relating to the sub-content based on a secret key corresponding to the public key. The recording device acquires and records the verification information on the second recording medium that is rewritable. The reproducing device acquires the key data from the first recording medium and the verification information from the second recording medium, derives the public key from the key data, verifies the verification information using the public key, and reproduces the sub-content if the verification succeeds.
摘要:
An elliptic curve converting device that converts a first elliptic curve defined on a finite field F into a second elliptic curve defined on the finite field F comprises: an elliptic curve generating unit 210 that searches an elliptic curve that satisfies a speeding-up condition that reduces calculation quantity of arithmetic on the elliptic curve among a group of isogenous elliptic curves of degree L1 that is a group of elliptic curves that has the same order as and a certain relationship with the first elliptic curve; an elliptic curve condition judgment unit 220 that judges whether the elliptic curve that satisfies the speeding-up condition is searched or not by the elliptic curve generating unit 210; and an elliptic curve output unit 230 that outputs an elliptic curve in the case that the elliptic curve condition judgment unit 220 judges that the elliptic curve that satisfies the speeding-up condition is searched.
摘要:
An information security device receives an input of prime q, and generates prime N that is larger than prime q. In the information security device, a partial information setting unit generates number u such that 2×u×q+1≠0 mod Li (i=1, 2, . . . , n). A random number generating unit generates random number R′. A judgement target generating unit generates R=u+L1×L2× . . . ×Ln×R′ and N=2×R×q+1, using number u and random number R′. A primality judging unit judges the primality of number N, using numbers N and R generated by the judgement target generating unit.
摘要翻译:信息安全设备接收素数q的输入,并产生大于素数q的素数N. 在信息安全装置中,部分信息设定单元生成数字u,使得2xuxq + 1 <> 0 mod L i(i = 1,2,...,n)。 随机数生成单元生成随机数R'。 判断目标产生单元生成R = u + L 1 xL 2 x x。 。 。 xL xR'和N = 2xRxq + 1,使用数u和随机数R'。 原语判断单元使用由判断目标生成单元生成的数字N和R来判断数字N的原语。
摘要:
A transmission device including: copy unit that extracts part or all of partial contents, as tracking information, from a content, and copies the extracted tracking information, thereby generating pieces of tracking information; candidate information obtaining unit that obtains pieces of candidate information respectively corresponding to the pieces of tracking information; evidence information obtaining unit that obtains evidence information generated dependently on a piece of candidate information selected by the reception device from among the pieces of candidate information; hash generating unit that generates hash values respectively in accordance with the pieces of candidate information; embed unit that embeds the hash values respectively into the pieces of tracking information, and embeds the evidence information into each piece of tracking information; and transmit unit that transmits each piece of tracking information in which a hash value and the evidence information have been embedded.
摘要:
An encrypted communication system, capable of performing processing with the speed higher than the conventionally achieved speed, includes an encryption device and a decryption device sharing parameters that satisfy p=3 and q=2^k (k: an integer of 2 or greater). The decryption device generates a public key and a private key using the parameters, the encryption device encrypts a plain text using the public key, and then, the decryption device decrypts the encrypted text using its own private key.
摘要:
A signature generation apparatus and a signature verification apparatus which can prevent the occurrence of norm zero vector forgery attack. The signature generation apparatus (110) includes a signature generation unit (114) which generates signature data (S) for a message (m) using a private key stored in a private key storage unit (112), and converts the format of the signature data (S) so that the first sub-element of the N sub-elements in the signature data (S) indicates 0 without changing the norm of the signature data (S). The signature verification apparatus (120) includes a signature verification unit (124) which judges whether or not the first sub-element of the N sub-elements included in the signature data (S) indicates 0, and determines the signature data (S) as unauthorized data when judging that it is not 0.