Abstract: A cryptographic system includes encryption logic that is configured to encrypt input data by performing a mask operation on the input data using an address associated with the input data.

Abstract: An active shield can be configured to receive a test signal, and configured to output a plurality of shield signals, derived from the test signal, via a plurality of signal paths. A compare logic can be configured to compare the test signal with each of the plurality of shield signals to provide at least two comparison signals indicating comparison results and can be configured to output the at least two comparison signals. A detection and decision logic can be configured to determine whether the active shield is subject to attack based on patterns of the at least two comparison signals.

Abstract: A semiconductor memory device according to some embodiments includes a random converter that receives data and address information including a start address value and an end address value of the address from a central processing unit (CPU), generates and stores at least one random number for each address value from the start address value to the end address value, performs a logical operation on the random number and the data corresponding to the address, and responsively generates randomized data to be stored in memory. Accordingly, the semiconductor memory device randomizes a power consumption signature that can occur when data is stored, thereby writing and reading data in a manner that is resistant to a power attack.

Abstract: An access control method is described for an encrypted program transmitted by an operator to a plurality of groups of subscribers, where each group of subscribers has a group key KG, and each subscriber is able to receive from the operator an operating key KT, enciphered by the group key KG for decryption of the transmitted program. The method further involves linking the enciphered operating key KT to a random value R to generate a secret code, transmitting the secret code to subscribers prior to transmission of the encrypted program, and transmitting the random value R to subscribers for calculation of the operating key KT.

Abstract: A semiconductor memory device according to some embodiments includes a random converter that receives data and address information including a start address value and an end address value of the address from a central processing unit (CPU), generates and stores at least one random number for each address value from the start address value to the end address value, performs a logical operation on the random number and the data corresponding to the address, and responsively generates randomized data to be stored in memory. Accordingly, the semiconductor memory device randomizes a power consumption signature that can occur when data is stored, thereby writing and reading data in a manner that is resistant to a power attack.

Abstract: An active shield can be configured to receive a test signal, and configured to output a plurality of shield signals, derived from the test signal, via a plurality of signal paths. A compare logic can be configured to compare the test signal with each of the plurality of shield signals to provide at least two comparison signals indicating comparison results and can be configured to output the at least two comparison signals. A detection and decision logic can be configured to determine whether the active shield is subject to attack based on patterns of the at least two comparison signals.

Abstract: A cryptographic system includes encryption logic that is configured to encrypt input data by performing a mask operation on the input data using an address associated with the input data.

Abstract: This invention relates to an access control method for an encrypted program transmitted by an operator to a plurality of groups of subscribers, each group of subscribers being issued with a group key KG, and each subscriber being able to receive from the operator an operating key KT, enciphered by to the group key KG, for decryption of the transmitted program.