Encryption/decryption apparatus
First Claim
1. An encryption/decryption apparatus comprising:
- a random number supply unit configured to supply a random number;
a first Exclusive OR circuit configured to perform an Exclusive OR between input data and the random number;
an operation circuit configured to perform an operation of one of encryption or decryption of output data from the first Exclusive OR circuit;
a selection signal generation unit configured to repeatedly generate a selection signal in synchronization with output timing of data from the operation circuit;
a data register circuit having a plurality of data hold units, the data register circuit configured to hold data from the operation circuit in one data hold unit in response to the selection signal, the selection signal selectively indicating the one data hold unit from among the plurality of data hold units, the data register circuit further configured to supply the data from the one data hold unit to the operation circuit; and
a second Exclusive OR circuit configured to perform an Exclusive OR between the data supplied from the data register circuit and the random number;
wherein the operation circuit is further configured to recursively perform the one operation on the data supplied from the data register circuit and to output operated data to the data register circuit.
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Accused Products
Abstract
A first Exclusive OR circuit operates an Exclusive OR between input data and a predetermined random number. An operation circuit performs one operation of encryption and decryption of output data from the first Exclusive OR circuit. A data register circuit, which has a plurality of data hold units, holds data from the operation circuit in one data hold unit of the plurality of data hold units in response to a selection signal, and supplies the data from the one data hold unit to the operation circuit. A second Exclusive OR circuit performs an Exclusive OR between output data from the data register circuit and the random number. The operation circuit recursively performs the one operation of the data from the data register circuit and outputs next data to the data register circuit.
8 Citations
19 Claims
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1. An encryption/decryption apparatus comprising:
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a random number supply unit configured to supply a random number; a first Exclusive OR circuit configured to perform an Exclusive OR between input data and the random number; an operation circuit configured to perform an operation of one of encryption or decryption of output data from the first Exclusive OR circuit; a selection signal generation unit configured to repeatedly generate a selection signal in synchronization with output timing of data from the operation circuit; a data register circuit having a plurality of data hold units, the data register circuit configured to hold data from the operation circuit in one data hold unit in response to the selection signal, the selection signal selectively indicating the one data hold unit from among the plurality of data hold units, the data register circuit further configured to supply the data from the one data hold unit to the operation circuit; and a second Exclusive OR circuit configured to perform an Exclusive OR between the data supplied from the data register circuit and the random number; wherein the operation circuit is further configured to recursively perform the one operation on the data supplied from the data register circuit and to output operated data to the data register circuit. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
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19. A method for performing encryption/decryption comprising the steps of:
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identifying a random number; performing an Exclusive OR operation between input data and the random number; performing, at an operation circuit, an operation of one of encryption or decryption of output data from the Exclusive OR operation; identifying a selection signal in synchronization with output timing of data from the operation circuit; in response to the selection signal, holding data from the operation circuit in one data hold unit of a plurality of data hold units of a data register circuit, the selection signal selectively indicating the one data hold unit from among the plurality of data hold units; supplying the data from the one data hold unit to the operation circuit; recursively performing, at the operation circuit, the operation on the data supplied from the one data hold unit; and output operated data from the operation circuit to the data register circuit.
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Specification