Abstract: A circuit for converting Boolean and arithmetic masks includes “m” converting units, wherein m is an integer greater than 1.

Abstract: A method of countering side-channel attacks on an elliptic curve cryptosystem (ECC) is provided. The method comprises extending a definition field of an elliptic curve of the ECC to an extension ring in a first field; generating a temporary ciphertext in the extension ring and countering attacks on the ECC; and generating a final ciphertext for the first field if a fault injection attack on the ECC is not detected. The countering of attacks on the ECC may comprise countering a power attack on the ECC. Checking if there is a fault injection attack on the ECC may be performed by determining if the temporary ciphertext satisfies a second elliptic curve equation. The fault detection algorithms takes place in a small subring of the extension ring, not in the original field, to minimize the computational overhead. The method can improve the stability of the ECC and reduce computational overhead of the ECC.

Abstract: Provided are a modular multiplication method with an improved arithmetic operation, a modular multiplier and a cryptograph calculating system having the modular multiplier. The modular multiplication method comprises performing a first arithmetic operation including a first multiplication on a first bit string of a multiplicand and a first bit string of a multiplier and a first reduction for eliminating partial bits of the first multiplication result, performing a second arithmetic operation including a second multiplication on a second bit string of the multiplicand and a second bit string of the multiplier and a second reduction for eliminating partial bits of the second multiplication result, and calculating a modular multiplication result using the result of the first arithmetic operation and the result of the second arithmetic result. The first arithmetic operation and the second arithmetic operation are independently performed.

Abstract: A method and system for encrypting input data may include receiving an input point and a randomness rate and generating a random selection value and a random position value from the randomness rate. At least one of the input point and points encrypted by performing elliptic curve (EC) operation over a plurality of rounds may be randomly selected based on the randomness rate and the random position value. The selected point may be converted to a point representation directed by the random selection value. A finally encrypted output point may be generated by performing the EC operation over a plurality of rounds based on the input point and a secret key.

Abstract: A circuit for converting Boolean and arithmetic masks includes “m” converting units, wherein m is an integer greater than 1.

Abstract: Provided are a modular multiplication method with an improved arithmetic operation, a modular multiplier and a cryptograph calculating system having the modular multiplier. The modular multiplication method comprises performing a first arithmetic operation including a first multiplication on a first bit string of a multiplicand and a first bit string of a multiplier and a first reduction for eliminating partial bits of the first multiplication result, performing a second arithmetic operation including a second multiplication on a second bit string of the multiplicand and a second bit string of the multiplier and a second reduction for eliminating partial bits of the second multiplication result, and calculating a modular multiplication result using the result of the first arithmetic operation and the result of the second arithmetic result. The first arithmetic operation and the second arithmetic operation are independently performed.

Abstract: A method of countering side-channel attacks on an elliptic curve cryptosystem (ECC) is provided. The method comprises extending a definition field of an elliptic curve of the ECC to an extension ring in a first field; generating a temporary ciphertext in the extension ring and countering attacks on the ECC; and generating a final ciphertext for the first field if a fault injection attack on the ECC is not detected. The countering of attacks on the ECC may comprise countering a power attack on the ECC. Checking if there is a fault injection attack on the ECC may be performed by determining if the temporary ciphertext satisfies a second elliptic curve equation. The fault detection algorithms takes place in a small subring of the extension ring, not in the original field, to minimize the computational overhead. The method can improve the stability of the ECC and reduce computational overhead of the ECC.

Abstract: Example embodiments of the present invention disclose a cryptographic logic circuit, which may include a first logic unit configured to execute at least one logic operation for a plurality of data pairs, the data pairs including random data and random masking data, and a second logic unit configured to execute a logic operation for the results of the first logic unit. Also, the example embodiments of the present invention, which may a method of performing a logic operation in a cryptographic logic circuit including converting a plurality of input data and random data into a plurality of random masking data, executing a first logic operation on the random data and random masking data, executing a second logic operation on the output of the first logic operation, and outputting the result of the second logic operation random masking data.

Abstract: A method and system for encrypting input data may include receiving an input point and a randomness rate and generating a random selection value and a random position value from the randomness rate. At least one of the input point and points encrypted by performing elliptic curve (EC) operation over a plurality of rounds may be randomly selected based on the randomness rate and the random position value. The selected point may be converted to a point representation directed by the random selection value. A finally encrypted output point may be generated by performing the EC operation over a plurality of rounds based on the input point and a secret key.

Abstract: Provided are example embodiments of a cryptographic method and apparatus thereof. The cryptographic method and apparatus may be implemented in Weierstrass and Hessian forms, and for the point representations, Affine, Ordinary Projective, Jacobian Projective, and Lopez-Dahab Projective. The cryptographic method and apparatus may prevent confidential information from leakage by checking faults in a basic point due to certain attacks, faults in definition fields, and faults in elliptic curve (EC parameters before outputting final cryptographic results.

Abstract: An Advanced Encryption System (AES) compliant circuit can include a multiplier circuit configured to multiply masked data with masking data to provide multiplied outputs therefrom and a combinatorial circuit coupled to the multiplier circuit and configured to combine the multiplied outputs with at least one of the masked data or at least one of the masking data.

Abstract: A system and recording medium for securing data and methods thereof including a modular exponentiation. One embodiment includes first masking a message, second masking an exponent, and executing a modular exponentiation based at least one of the first and second maskings. Another embodiment includes first masking a message, second masking at least one exponent, executing a modular exponentiation based at least one of the first and second maskings, detecting an error, executing a modular multiplication operation based on the detection and diffusing the detected error to generate an electronic signature. Yet another embodiment includes first masking a message, second masking at least one exponent, executing a modular exponentiation based at least one of the first and second maskings, detecting an error, and generating an electronic signature based on the detected error.

Abstract: A cryptographic apparatus, a cryptographic method, and a computer readable storage medium provide for conversion between Boolean-masked data and arithmetic-masked data in a manner that allows for a reduction in computational overhead and hardware overhead. The cryptographic apparatus comprises: a first masking circuit which receives a first random number and data and outputs first-masked data; and a second masking circuit which receives a second random number and the first-masked data output from the first masking circuit, and outputs second-masked data.