Abstract: This disclosure relates to a method for securing the execution of a program by a processor, including a comparison instruction for comparing two data items, followed by a program operation which is selected as a function of a comparison result provided by the comparison instruction. The method may include, before the execution of the comparison instruction, calculating in various ways comparison data representative of the equality of the data to be compared, after the execution of the comparison instruction, verifying whether the comparison data calculated are consistent with the fact that the program operation is selected or not selected, and activating an error signal if the comparison data are mutually inconsistent or inconsistent with the result of the comparison.

Abstract: A method of processing programming instructions may include identifying an instruction to be fetched; determining if the identified instruction is protected; if the identified instruction is protected, selecting an alternate instruction from a plurality of alternate instructions corresponding to the identified protected instruction, and fetching the selected alternate instruction; and if the identified instruction is not protected, fetching the identified instruction. Identifying the instruction to be fetched may include identifying an address stored in a program address pointer. Determining if the identified instruction is protected may include comparing the address stored in the program address pointer to one or more addresses stored in a first memory portion, and determining if there is a correspondence.

Abstract: Software can be downloaded securely using a multi-encryption method, where the decryption is completed when the software is executed. In one aspect, a multi-encrypted data item is received. One or more of the encryptions on the multi-encrypted data item is decrypted, yielding a partially decrypted data item. The partially decrypted data item is stored in a reserved portion of a storage medium. The partially decrypted data item is fetched from the storage medium and decrypted to yield the data item. The decryption can be performed using one or more circuits that implement multiple decryption processes, including multiple algorithm-key combinations.

Abstract: Systems, methods and program products for a first central processing unit (CPU) configured to perform tasks that do not require manipulation of sensitive information and a second CPU that is configured to perform tasks that manipulate the sensitive information on behalf of the first CPU. The first CPU and the second CPU can communicate through a secure interface. The first CPU cannot access the sensitive information within the second CPU.

Abstract: A secure communication interface for a secure multi-processor system is disclosed. The secure communication interface can include a secure controller that is operable to transfer data between a first memory that is directly accessible by a first (master) processor and a second memory that is directly accessible by a secure second (slave) processor in the multi-processor system. One or more control and status registers accessible by the processors facilitate secure data transfer between the first memory and a memory window defined in the second memory. One or more status and violation registers shared by the processors can be included in the secure communication interface for facilitating secure data transfer and for reporting security violations based on a rule set.

Abstract: A method and system for controlling timing in a processor is disclosed. In one aspect of the present invention, the method comprises fetching a plurality of instructions, wherein each instruction has a first default execution time during a first condition, and wherein each instruction has a second default execution time during a second condition; during a first mode, executing the plurality of instructions within a same execution time regardless of whether a condition is the first condition or the second condition; and during a second mode, executing the plurality of instructions within random execution time regardless of whether a condition is the first condition or the second condition. According to the system and method disclosed herein, the method effectively modifies the timing of a processor by controlling and/or minimizing variations in the execution times of instructions.

Abstract: Methods and apparatus for identifying a first flow control instruction in an executing program, the first instruction being associated with a first program address at which program execution will continue after execution of the first instruction. A determination is made as to whether the first program address is protected. If the first program address is protected, a first alternate program address is substituted for the first program address such that program execution will continue at the first alternate program address after execution of the first instruction.

Abstract: Software can be downloaded securely using a multi-encryption method, where the decryption is completed when the software is executed. In one aspect, a multi-encrypted data item is received. One or more of the encryptions on the multi-encrypted data item is decrypted, yielding a partially decrypted data item. The partially decrypted data item is stored in a reserved portion of a storage medium. The partially decrypted data item is fetched from the storage medium and decrypted to yield the data item. The decryption can be performed using one or more circuits that implement multiple decryption processes, including multiple algorithm-key combinations.

Abstract: Systems, methods and program products for a first central processing unit (CPU) configured to perform tasks that do not require manipulation of sensitive information and a second CPU that is configured to perform tasks that manipulate the sensitive information on behalf of the first CPU. The first CPU and the second CPU can communicate through a secure interface. The first CPU cannot access the sensitive information within the second CPU.

Abstract: Methods and apparatus for identifying a first flow control instruction in an executing program, the first instruction being associated with a first program address at which program execution will continue after execution of the first instruction. A determination is made as to whether the first program address is protected. If the first program address is protected, a first alternate program address is substituted for the first program address such that program execution will continue at the first alternate program address after execution of the first instruction.

Abstract: A method of processing programming instructions may include identifying an instruction to be fetched; determining if the identified instruction is protected; if the identified instruction is protected, selecting an alternate instruction from a plurality of alternate instructions corresponding to the identified protected instruction, and fetching the selected alternate instruction; and if the identified instruction is not protected, fetching the identified instruction. Identifying the instruction to be fetched may include identifying an address stored in a program address pointer. Determining if the identified instruction is protected may include comparing the address stored in the program address pointer to one or more addresses stored in a first memory portion, and determining if there is a correspondence.