CRYPTOGRAPHIC PROCESSING APPARATUS, CRYPTOGRAPHIC PROCESSING METHOD, AND STORAGE MEDIUM STORING CRYPTOGRAPHIC PROCESSING PROGRAM FOR REALIZING HIGH-SPEED CRYPTOGRAPHIC PROCESSING WITHOUT IMPAIRING SECURITY
US6570989B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 21, 1999 |
| Grant date | May 27, 2003 |
| Priority date | — |
| Expiry date | Apr 21, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2209/24
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
To provide a cryptographic processing apparatus that cryptographically processes input data using substitution table data to generate output data. A storing unit stores (2{circumflex over ( )}N) sets of substitution data that each have a predetermined number of bits, where N is an integer no less than 2. A dividing unit divides the input data which is (N×M) bits long into M sets of N-bit subdata, where M is an integer no less than 2. A substituting unit receives an input that is any of: the M sets of N-bit subdata; and at least one set of N-bit input merged data generated by performing a merge process on the M sets of N-bit subdata, specifies one of the (2{circumflex over ( )}N) sets of substitution data in the storing unit for each N bits of the input, and outputs the set of substitution data specified for each N bits of the input. A fixed conversion performing unit performs a plurality of different fixed conversions on at least one set of substitution data outputted from the substituting unit, to generate M sets of converted data that each have the predetermined number of bits. An output data generating unit generates the output data that is (N×M) bits long, based on …
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