摘要:
An encryption/decryption unit includes a first data encryption/decryption section for performing an encryption or decryption process, a first data substitution section for performing data substitution of an output from the first encryption/decryption section according to a predetermined permutation table, a second data encryption/decryption section for performing an encryption or decryption process for an output from the first data substitution section, a second data substitution section for performing data substitution of an output from the second data encryption/decryption section according to a predetermined permutation table, and a third data encryption/decryption section for performing an encryption or decryption process for an output from the second data substitution section.
摘要:
An encryption/decryption unit includes a first data encryption/decryption section for performing an encryption or decryption process, a first data substitution section for performing data substitution of an output from the first encryption/decryption section according to a predetermined permutation table, a second data encryption/decryption section for performing an encryption or decryption process for an output from the first data substitution section, a second data substitution section for performing data substitution of an output from the second data encryption/decryption section according to a predetermined permutation table, and a third data encryption/decryption section for performing an encryption or decryption process for an output from the second data substitution section.
摘要:
There are disclosed an extended key generator, encryption/decryption unit, and storage medium, in which as each of key transform functions, a transform process is done by an S box (substitution table) on the basis of a first key obtained from the inputted key, and an adder computes a corresponding one of extended keys on the basis of a value obtained by shifting the transformed result of the S box to the left, and a second key obtained from the inputted key.
摘要:
In an encryption apparatus for encrypting a data body to contain an encrypted data body in transmission data and transmitting the transmission data to a receiver, the transmission data includes sender's key recovery data obtained by encrypting recovery information for recovering a key for decrypting the encrypted data body to allow a key recovery agent registered by a sender to decrypt the recovery information, and receiver's key recovery data obtained by encrypting the recovery information for recovering the key for decrypting the encrypted data body to allow a key recovery agent registered by a receiver to decrypt the recovery information.
摘要:
An encryption apparatus for block data, comprises a first processing unit randomizing the block data in units of first portions obtained by dividing the block data, and a second processing unit diffusing the block data output from the first processing unit with respect to a second portion of the block data which is wider than the first portion. The first processing unit comprises first nonlinear processing units nonlinearly transforming the block data in units of the first portions. The second processing unit comprises a first linear diffusion processing unit linearly diffusing the second portion of the block data. At least one of the first nonlinear processing units comprises second nonlinear processing units nonlinearly transforming the block data in units of the first portions, and a second linear diffusion processing unit linearly diffusing the second portion of the block data.
摘要:
An encryption apparatus for block data, comprises a first processing unit randomizing the block data in units of first portions obtained by dividing the block data, and a second processing unit diffusing the block data output from the first processing unit with respect to a second portion of the block data which is wider than the first portion. The first processing unit comprises first nonlinear processing units nonlinearly transforming the block data in units of the first portions. The second processing unit comprises a first linear diffusion processing unit linearly diffusing the second portion of the block data. At least one of the first nonlinear processing units comprises second nonlinear processing units nonlinearly transforming the block data in units of the first portions, and a second linear diffusion processing unit linearly diffusing the second portion of the block data.
摘要:
Expanded key schedule circuit for common key encryption system in which expanded keys are used in a predetermined order in data randomizing process for encryption and in a reversed order in data randomizing process for decryption, comprises round processing circuits connected in series. The round processing circuits subject the common key or sub key of a previous stage to a round function to output a sub key. The sub key of the last stage is equal to the common key. The expanded keys are generated from the sub keys.
摘要:
An encryption apparatus for block data, comprises a first processing unit randomizing the block data in units of first portions obtained by dividing the block data, and a second processing unit diffusing the block data output from the first processing unit with respect to a second portion of the block data which is wider than the first portion. The first processing unit comprises first nonlinear processing units nonlinearly transforming the block data in units of the first portions. The second processing unit comprises a first linear diffusion processing unit linearly diffusing the second portion of the block data. At least one of the first nonlinear processing units comprises second nonlinear processing units nonlinearly transforming the block data in units of the first portions, and a second linear diffusion processing unit linearly diffusing the second portion of the block data.
摘要:
In each stage, multiple parallel nonlinear transformation modules each perform local lower-level diffusion, then a diffusion module performs higher-level diffusion over the block width and multiple parallel nonlinear transformation modules each perform local lower-level diffusion. This operation is repeated a predetermined number of times corresponding to the number of stages. Each nonlinear transformation module is formed into the nested SPN structure by arranging alternately nonlinear transformation modules and a diffusion module. The diffusion module performs linear transformation for spreading the state of at least one bit in input data to the preceding nonlinear transformation modules to at least one bit in input data to the succeeding nonlinear transformation modules.
摘要:
A pair of a pattern of a mask and a mask pattern obtained by bit inversion of the mask is prepared for each round function in a data scrambler. Every time encryption is to be performed, one mask pattern of the pair is randomly selected by a switch, and an exclusive OR of an input to an S-box and the selected mask pattern is calculated. In addition, an exclusive OR of an output from the S-box and bits of inverse permutation of the mask is calculated. The exclusive ORs are calculated in advance and stored as a table in the S-box. Furthermore, an exclusive OR of the output from each round function and a mask is calculated and concealed. The influence of the mask is removed by calculating the exclusive OR with the mask again on the next round.