Abstract: An encryption/decryption apparatus and a power analysis protecting method thereof are provided. The encryption/decryption apparatus adapted to perform encryption/decryption operation on digital data includes a data encryption/decryption unit, a random number generator, and a power analysis protecting circuit. The data encryption/decryption unit receives the digital data and performs an encryption/decryption operation on the digital data. The random number generator is used to generate random number data, the random number data has N bits, and N is a positive integer. The power analysis protecting circuit generates M kinds of power signals having different levels according to each bit data of the random number data when the random number data is received by the power analysis protecting circuit, and M is equal to the Nth power of 2.

Abstract: A cracking method for cracking a secret key of an encrypting device includes: building up a leakage model for the encrypting device; performing a mathematical calculation on the leakage model, according to a plurality of sets of input data, to generate a mathematical model; generating a plurality of sets of hypothesized keys; generating a plurality of sets of simulation data corresponding to the hypothesized keys using the mathematical model; providing the input data for the encrypting device and detecting a plurality of sets of leakage data generated by the encrypting device; performing the mathematical calculation on the leakage data to generate calculated data; determining a correlation between each of the simulation data and the calculated data; and determining one of the hypothesized keys to be consistent with the secret key according to the correlation.

Abstract: A cracking method for cracking a secret key of an encrypting device includes: building up a leakage model for the encrypting device; performing a mathematical calculation on the leakage model, according to a plurality of sets of input data, to generate a mathematical model; generating a plurality of sets of hypothesized keys; generating a plurality of sets of simulation data corresponding to the hypothesized keys using the mathematical model; providing the input data for the encrypting device and detecting a plurality of sets of leakage data generated by the encrypting device; performing the mathematical calculation on the leakage data to generate calculated data; determining a correlation between each of the simulation data and the calculated data; and determining one of the hypothesized keys to be consistent with the secret key according to the correlation.

Abstract: An encryption/decryption apparatus and a power analysis protecting method thereof are provided. The encryption/decryption apparatus adapted to perform encryption/decryption operation on digital data includes a data encryption/decryption unit, a random number generator, and a power analysis protecting circuit. The data encryption/decryption unit receives the digital data and performs an encryption/decryption operation on the digital data. The random number generator is used to generate random number data, the random number data has N bits, and N is a positive integer. The power analysis protecting circuit generates M kinds of power signals having different levels according to each bit data of the random number data when the random number data is received by the power analysis protecting circuit, and M is equal to the Nth power of 2.