Rotation-based cipher
AssigneeQUALCOMM Incorporated
InventorsBilly Brumley, Roberto Avanzi
Life of this patent
Estimating the term…
Abstract
A cipher employs rotation of a substitution box (S-Box) value to provide both confusion and diffusion. In some aspects, for each iteration of an iterative cipher, a subset of a state value is expanded to calculate a rotation distance for rotating an S-Box value, whereby the rotated S-Box value is combined with the state value and the new state value is rotated for the next iteration. Advantageously, the cipher may be implemented in software (or other code) using conventional instructions, and without the need for large S-Box lookup tables.
Claims30
A method for generating a ciphered signal, comprising:
- receiving a first signal;
- determining a state value based on the first signal;
- determining a rotation distance based on the state value;
- rotating a first value based on the rotation distance;
- combining the rotated first value and the state value;
- and
- generating a second signal based on the combination of the rotated first value and the state value.
An apparatus for generating a ciphered signal, comprising:
- a memory circuit;
- and
- a processing circuit coupled to the memory circuit and configured to:
- receive a first signal from the memory circuit;
- determine a state value based on the first signal;
- determine a rotation distance based on the state value;
- rotate a first value based on the rotation distance;
- combine the rotated first value and the state value;
- and
- generate a second signal based on the combination of the rotated first value and the state value.
An apparatus for generating a ciphered signal, comprising:
- means for receiving a first signal;
- means for determining a state value based on the first signal;
- means for determining a rotation distance based on the state value;
- means for rotating a first value based on the rotation distance;
- means for combining the rotated first value and the state value;
- and
- means for generating a second signal based on the combination of the rotated first value and the state value.
A non-transitory computer-readable medium storing computer executable code, including code to:
- receive a first signal;
- determine a state value based on the first signal;
- determine a rotation distance based on the state value;
- rotate a first value based on the rotation distance;
- combine the rotated first value and the state value;
- and
- generate a second signal based on the combination of the rotated first value and the state value.
Dependencies are inferred from the claim text.