# US 2014/0192973 A1 · Encryption processing apparatus, encryption processing method, and computer program

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- Number: US 2014/0192973 A1
- Document ID: US20140192973A1
- Status: Published application
- Kind: A1
- Application number: 14/049,854
- Filed: 2013-10-09
- Published: 2014-07-10
- Earliest claimed: 2006-09-01
- Assignees: Sony Corporation
- Applicants: Sony Corporation
- Inventors: Taizo SHIRAI; Kyoji SHIBUTANI; Toru AKISHITA; Shiho MORIAI
- Web page: https://patentgrep.com/patent/US20140192973A1

## CPC

- H04L 9/0625: {with splitting of the data block into left and right halves, e.g. Feistel based algorithms, DES, FEAL, IDEA or KASUMI}
- G09C 1/00: Apparatus or methods whereby a given sequence of signs, e.g. an intelligible text, is transformed into an unintelligible sequence of signs by transposing the signs or groups of signs or by replacing them by others according to a predetermined system (cryptographic typewriters G09C3/00)
- H04L 9/002: {Countermeasures against attacks on cryptographic mechanisms (network architectures or network communication protocols for protection against malicious traffic H04L63/1441)}
- H04L 9/0631: {Substitution permutation network [SPN], i.e. cipher composed of a number of stages or rounds each involving linear and nonlinear transformations, e.g. AES algorithms}
- H04L 2209/122: Hardware reduction or efficient architectures
- H04L 2209/125: Parallelization or pipelining, e.g. for accelerating processing of cryptographic operations
- H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M)
- G09C: CIPHERING OR DECIPHERING APPARATUS FOR CRYPTOGRAPHIC OR OTHER PURPOSES INVOLVING THE NEED FOR SECRECY

## Abstract

A common-key blockcipher processing configuration with enhanced immunity against attacks such as saturation attacks and algebraic attacks (XSL attacks) is realized. In an encryption processing apparatus that performs common-key blockcipher processing, S-boxes serving as non-linear transformation processing parts set in round-function executing parts are configured using at least two different types of S-boxes. With this configuration, the immunity against saturation attacks can be enhanced. Also, types of S-boxes present a mixture of different types. With this configuration, the immunity against algebraic attacks (XSL attacks) can be enhanced, thereby realizing a highly secure encryption processing apparatus.

## Claims

### Claim 1

An encryption processing apparatus that performs encryption processing, characterized by comprising:
an encryption processing part that performs data transformation processing in which a round function is repeated for a plurality of rounds,
wherein the encryption processing part is configured to perform non-linear transformation processing applying S-boxes in processing of executing round functions in the respective rounds, and
wherein the encryption processing part is configured to perform processing using at least two different types of S-boxes as the S-boxes applied in the non-linear transformation processing.

### Claim at position 2

2-16. (canceled)