Abstract:
A computing device is provide, configured to compute a function of one or more inputs, the device comprising a storage device storing one or more look-uptables used in the computation of said function, the look-up tables mapping input values to output values, the look-up table being constructed with respect to the first error correcting code, a second error correcting code, a first error threshold and a second error threshold, such that any two input values (112) that each differ at most a first error threshold number of bits from a same code word of the first error correcting code, are mapped to respective output values (131- 38) that each differ at most a second error threshold number of bits from a same code word of the second error correcting code, wherein the first error threshold is at least 1 and at most the error correcting capability (t1) of the first error correcting code, and the second error 10 threshold is at most the error correcting capability (t2) of the second error correcting code.
Abstract:
Embodiments of the invention provide a method and a device for manipulating data by converting masked data in a first representation of a finite field into converted data in a second representation of the finite field, and manipulating the converted data to obtain manipulated masked data.
Abstract:
Within a data processing systems supporting conditional write processing operations, a trash register is provided such that when non-write conditions are encountered a register write is made to the trash register rather than the data register specified by the conditional write operation. Thus the power signature associated with whether or not a register write does or does not occur is masked. The trash register activity may be programmable enabled and disabled by a configuration parameter stored within a system configuration register.
Abstract:
Within a data processing systems supporting conditional write processing operations, a trash register is provided such that when non-write conditions are encountered a register write is made to the trash register rather than the data register specified by the conditional write operation. Thus the power signature associated with whether or not a register write does or does not occur is masked. The trash register activity may be programmable enabled and disabled by a configuration parameter stored within a system configuration register.
Abstract:
The invention relates to a method for increasing the security of a CPU, which is characterized by using a pipeline that comprises a fetch stage (1), a decode stage (2), an execute stage (3) and a writeback stage (4), said writeback stage having at least one register (41) and at least one register (42). When the register (41) is used, the status of the CPU remains unchanged, while when the register (42) is used, the status of the CPU is changed. The inventive method is further characterized in that in the decode stage at least one randomly chosen code sequence is inserted as the dummy code sequence or filler, thereby making an attack by DPA more difficult.
Abstract:
The invention concerns a countermeasure method in an electronic component using a secret key algorithm K on an input message M characterised in that the execution of an operation OPN or of a sequence of operations comprising manipulating bit by bit an input information D, to supply an output information OPN(D), comprises the following steps: drawing a random value, of one first random information U, of identical size as the input information D; calculating s second random information V, by performing an exclusive OR between the input information and the firs random information U; executing the operation OPN or the sequence of operations successively to the first input information U and to the second random information V, supplying respectively a first random result OPN(U) and a second random result OPN(V).
Abstract:
New techniques for cracking sealed platforms have recently been discovered which observe power modulation during execution of a software encryption program on a computer processor. Particularly vulnerable to such simple power analysis and differential power analysis attacks are smart cards which employ Data Encryption Standard (DES) protection. The invention protects against such attacks by mapping data onto "Hamming-neutral" values, that is, bytes which have the same number of 1-values, so power signatures do not vary during execution. The Hamming-neutral values are assigned to each bit-string in a targeted data set, rather than in a bit-wise manner as known. This approach has a number of advantages: it is less demanding of system resources, it results in a larger number of encodings for an attacker to decipher, and it can be applied to various components including: addressing, indexing, stored data and input data. Many variations and improvements are also described.
Abstract:
The invention relates to a microprocessor system comprising a central control and processing unit (1), a bus (2) with a bus status line (21) and data/address lines (22), and comprising units (3, 4, 5) connected to the bus (2). When none of the units (3, 4, 5) are actuated by the control and processing unit (1), random data values (12) are transmitted to the data/address lines (22). This enables the profile of the current of the microprocessor system to be concealed with regard to the useful information to be transmitted via the bus (2).
Abstract:
The invention relates to a method, in which the data to be encrypted is linked by a random number using an exclusive-OR operation prior to encryption. According to the invention, the encryption program is modified in such a way that the standard encryption text can be ultimately retrieved. The inventive method provides protection against the DPA (Differential Power Analysis) attack.