Thales Dis France Sa

Thales Dis France Sas

Gemalto Sa

Sylvain Leveque

Aline Gouget

Karine Villegas

Jan Vacek

Fabrice Perion

Stéphane Grellier

Michael Adjedj

Protection of a data file to be used by a white-box cryptography software application installed in memory of a device to prevent the malevolent use of a digital copy of the data file by a white-box cryptography (WBC) software application installed in memory of another device. The mechanism includes extracting an unique identifier for the device from the environment of the device and modifying data in the data file according to the unique identifier, the available white-box cryptography software application includes a software security layer to retrieve the unique identifier from the environment of the device in which the software application is installed and to use this unique identifier in combination with the stored data file when executing, the result of the execution being correct only in case where the correct unique identifier has been extracted by the executed WBC software application.

Anti cloning for white box protected data

The present invention relates to a method to intrinsically protect a computer program having a driving value dedicated to handle sensitive data, said driving value comprising a plurality of N computation units to perform computations using sensitive data and susceptible to let sensitive data leak, each unit having V possible values, said method comprising a step of unrolling k parts of P units, with P&#x3e;1 and P&#x3c;N and N&#x2265;P*k, by rewriting them in an equivalent sequence of computations protecting the sensitive data, said unrolling step resulting in a plurality of V{circumflex over (&#x2003;)}P possible parts of P units, said method further comprising the step of introducing, in the finally executed computer program, instructions to dynamically execute the driving value by selecting, at end of each executed part, the next part to be executed among the possible parts.

Partial unrolling for software security

A processing unit executes a sensitive computation using multiple different and independent branches that each necessitate a given number of processing unit time units to be executed. Each execution of a sensitive computation includes: generating at least as many identifiers as the number of branches; associating each identifier to a unique branch; generating a random permutation of identifiers, wherein the number of occurrences of each identifier in the permutation is at least equal to the number of processing unit time units in the shortest of the branches; successively determining, wherein the determining includes processing each identifier in the random permutation, which branch to execute by each successive processing unit time units according to the identifier in the random permutation; and for each identifier of the random permutation, executing a processing unit time unit for the branch determined according to the identifier in the random permutation.

Random execution of multiple different and independent branches of a sensitive computation against various attacks

Growing community of inventors

Gemenos, France

Sylvain Leveque