摘要:
A plurality of round processing parts (38) are provided each of which contains a nonlinear function part (304), and each nonlinear function part (304) comprises: a first key-dependent linear transformation part (341) which performs a linear transformation based on a subkey; a splitting part (342) which splits the output from the first key-dependent linear transformation part into n pieces of subdata; a first nonlinear transformation part (343) which nonlinearly transforms those pieces of subdata, respectively; a second key-dependent linear transformation part (344) which linearly transforms those nonlinearly transformed outputs based on a subkey and outputs n pieces of transformed subdata; a second nonlinear transformation part (345) which nonlinearly transforms those transformed subdata; and a combining part (346) which combines the nonlinearly transformed outputs. An n×n matrix, which represents the linear transformation in the second key-dependent linear transformation part (344), is formed by n vectors whose Hamming weights are equal to or larger than T−1 for a security threshold T, thereby increasing the invulnerability against differential cryptanalysis and linear cryptanalysis.
摘要:
It is desired to share one circuit by an encryption unit 200 and a decryption unit 500. A normal data transformation unit (FL) 251 and an inverse data transformation unit (FL−1) 273 are located at point symmetry on a non-linear data transformation unit 220, and a normal data transformation unit (FL) 253 and an inverse data transformation unit (FL−1) 271 are located at point symmetry on the non-linear data transformation unit 220. Therefore, the encryption unit 200 and the decryption unit 500 can be configured using the same circuits.
摘要:
It is desired to share one circuit by an encryption unit 200 and a decryption unit 500. A normal data transformation unit (FL) 251 and an inverse data transformation unit ((FL−1)) 273 are located at point symmetry on a non-linear data transformation unit 220, and a normal data transformation unit (FL) 253 and an inverse data transformation unit ((FL−1)) 271 are located at point symmetry on the non-linear data transformation unit 220. Therefore, the encryption unit 200 and the decryption unit 500 can be configured using the same circuits.
摘要:
It is desired to share one circuit by an encryption unit 200 and a decryption unit 500. A normal data transformation unit (FL) 251 and an inverse data transformation unit (FL−1) 273 are located at point symmetry on a non-linear data transformation unit 220, and a normal data transformation unit (FL) 253 and an inverse data transformation unit (FL−1) 271 are located at point symmetry on the non-linear data transformation unit 220. Therefore, the encryption unit 200 and the decryption unit 500 can be configured using the same circuits.
摘要:
In a method for permuting and dividing 16 pieces of k-bit data held in 4k-bit long registers T0. T1, T2 and T3, k being an integer, the data of each register Ti is ANDed with a desired one of mask data (00ffff00), (ff0000ff), (0000ffff) and (ffff0000), and such ANDs are ORed to obtain desired permuted data.
摘要:
In a halftoning unit of a laser printer and the like, a high speed, high density and high gradations halftoning is realized by multi-value implementation by clustered dot concentrated dither halftoning (known as a sub-matrix method) and PWM distributing gradation among the plurality of halftone dots with a small memory and circuit. For this purpose, the value of the difference between an input gradation value ni and a threshold value nc, &Dgr;n=ni−nc, is shortened within a range of 0 to &Dgr;h and the lower s bit of &Dgr;h is removed by a round-down or round-up process. Meanwhile, a threshold array is generated from an extended threshold pattern obtained by combining threshold patterns of 2s whose threshold interval is &Dgr;h, i.e. &Dgr;Ah×K, &Dgr;h×K+1, . . . , &Dgr;×K+2(s−1). Thereby, a halftone dot dither process in which the PWM gradation increases distributively among the 2s dots may be realized with a small scale memory and circuit.
摘要:
A message delivery system which can guarantee the authenticity of a user, the reliability of a message delivery, and the authenticity of the message delivery, while preventing an illegal act, and which can prove them at a later time. The system has an information provider terminal including a user authentication unit for carrying out a user authentication of the user according to a zero knowledge interactive proof protocol using check bits E generated according to a work key W, and a transmission unit for transmitting to the user a ciphertext C in which a message M to be delivered to the user is enciphered according to a secret key cryptosystem by using the work key W, and the check bits E. The system also has a user terminal including a message reception unit for taking out the work key W by using at least the check bits E, and obtaining the message M by deciphering the ciphertext C according to the secret key cryptosystem by using the work key W.
摘要:
A scheme for message delivery which can guarantee an authenticity of a user, a reliability of message delivery, and an authenticity of the message deliver, while preventing an illegal act, and which can prove them at later time. In this scheme, when the user requests a delivery of a message to the information provider, the information provider carries out a user authentication of the user according to a zero knowledge interactive proof protocol using check bits E, transmits a ciphertext C in which a message M is enciphered according to a secret key cryptosystem by using a work key W, as a part of the check bits E, and delivers the message to the user in units of one bit or a plurality of bits. Then the information provider carries out a record management of a log data H for the zero knowledge interactive proof protocol. In addition, the information provider generates and transmits the check bits E by using at least the work key W, and the user takes out the work key W by using at least the check bits E, and obtains the message M by deciphering the ciphertext C according to the secret key cryptosystem by using the work key W.
摘要:
Permuted data (u1′, u2′, . . . , um′) of input data (u1, u2, . . . , un) expressed by the relationship [ u 1 ′ u 2 ′ ⋮ u m ′ ] = P [ u 1 u 2 ⋮ u n ] , are obtained by expressing the permuted data uj′ by uj′=ui′+Di, where j≠i and calculate uj′ for all of j.
摘要翻译:由关系表示的输入数据(u1,u2,...,un)的被许可数据(u1',u2',...,um')通过将置换的数据uj'表示为uj'= ui'+ Di ,其中j