Method and apparatus for a symmetric block cipher using multiple stages with type-1 and type-3 feistel networks

A system for carrying out a symmetric key block cipher using multiple stages on a computer, comprising:

• means for performing a first simple arithmetic operation in a first stage;
• means for performing a Type-3 Feistel unkeyed mixing operation in a second stage;
• means for performing a Type-1 Feistel keyed data-dependent rotation transform in a third stage, wherein a fixed location is used to specify an amount of the data-dependent rotation for each of a plurality of rounds of the third stage,
• means for performing a Type-3 Feistel unkeyed inverse mixing operation in a fourth stage;
• and
• means for performing a second simple arithmetic operation in a fifth stage, wherein the first simple arithmetic operation and the second simple arithmetic operation may be identical.

A computer program product for carrying out a symmetric key block cipher using multiple stages on a computer, the computer program product embodied in a computer-readable medium and comprising:

• computer-readable program code means for performing a first simple arithmetic operation in a first stage;
• computer-readable program code means for performing a Type-3 Feistel unkeyed mixing operation in a second stage;
• computer-readable program code means for performing a Type-1 Feistel keyed data-dependent rotation transform in a third stage, wherein a fixed location is used to specify an amount of the data-dependent rotation for each of a plurality of rounds of the third stage;
• computer-readable program code means for performing a Type-3 Feistel unkeyed inverse mixing operation in a fourth stage;
• and
• computer-readable program code means for performing a second simple arithmetic operation in a fifth stage, wherein the first simple arithmetic operation and the second simple arithmetic operation may be identical.