Abstract: This disclosure relates to a method for securely transmitting secret information to a user, including receiving by the user terminal, from a secure processor, a software component protected against tampering and reverse-engineering and configured to generate sets of adjacent pixels having a probability lower than 100% to be in a visible or invisible state, executing the software component by the user terminal, at a frame display refresh rate, to generate the pixel sets at the display refresh rate, inserting the pixel sets generated by each execution of the software component into one respective image frame, and activating display of the image frames at the frame display refresh rate, the image frames including information which is machine unintelligible as being formed of the pixel sets, the information becoming intelligible to a user at the display refresh rate based on a human visual system.

Abstract: In a general aspect, a method for authenticating a user including: receiving, from a secure processor, a software component configured to generate an image frame including encrypted information; executing the software component, the execution of the software component generating the image frame; displaying the image frame; superimposing on the image frame a semi-transparent image including transparent and opaque pixels configured to make the encrypted information intelligible to the user; acquiring from the user a response depending on the information; and transmitting the acquired response to the secure processor, the user being authenticated by the secure processor as a function of the acquired response.

Abstract: In a general aspect, a method for securely performing an operation using a non-secure user terminal can include: receiving and storing, by the user terminal, software component data defining a set of a plurality of software components performing the operation, the software component data including, for each software component, structure data and content data; receiving by the user terminal, from a secure processor, an execution request to perform the operation; selecting a valid software component among the set of software components; executing the selected software component; and setting the selected software component to invalid.

Abstract: In a general aspect, a method for authenticating a user can include: receiving, from a secure processor, a software component configured to generate an image frame including information intelligible to the user, and input data of the software component, the software component can include a first input for receiving a first input data having two randomly-selected valid values, and invalid values. The transmitted input data can include the valid values of the first input data. The method can also include, performing a plurality of times: selecting one of the valid values of the first input data in the transmitted input data, executing the software component by applying the transmitted input data to inputs of the software component and the selected valid value to the first input of the software component.

Abstract: A method for encoding can include generating a data structure defining a Boolean circuit including a memory storing original data, inputs and outputs, logic gates, and wires interconnecting the inputs, the logic gates and the outputs, the memory including, for each bit of the original data, a memory cell including a logic gate performing a logic operation depending on a value of the bit, the Boolean circuit configured to receive input data for selecting and reading a memory cell, and to provide a binary data of a bit read in the selected memory cell and address data of the bit in the original data. Generating the data structure including: generating a valid data for each binary state of each wires of the Boolean circuit, and computing truth table values of the logic gates as a function of the valid input and output data, and a logical operation of the logic gate.

Abstract: This disclosure relates to a method for securely transmitting a secret data to a user, including: receiving by a user terminal, from a secure processor, a software component protected against tampering and reverse-engineering and configured to receive input data and to provide output data, each of the input and output data having invalid values and two randomly-selected valid values corresponding to two respective randomly-selected binary states; executing the software component by the user terminal to generate the output data; receiving a decryption mask by the user terminal; and determining, by the user terminal, the binary states of the output data by combining a bit of each output data with a respective bit of the decryption mask, by an Exclusive OR operation, the secret data including the binary states of the output data.

Abstract: This disclosure relates to a method for authenticating a user from a user terminal, including: receiving by the user terminal, from a secure processor, a software component protected against tampering and reverse-engineering and configured to generate an image frame comprising random pixels having a probability lower than 100% to be visible in the image frame; executing the software component by the user terminal a plurality of times to generate a plurality of image frames; displaying the plurality of image frames at a frame display rate, the image frames including information which is machine unintelligible as being formed of the random pixels, the frame display rate being such that the information becomes intelligible to a user; acquiring a response from the user in relation with the information; and transmitting by the user terminal the response to the secure processor, the user being authenticated when the response corresponds to the information.

Abstract: This disclosure relates generally to a method for securely performing a sensitive operation from a user terminal, including transmitting from a secure processor to the user terminal, a software component protected against tampering and reverse-engineering and performing the sensitive operation, and inputs data of the software component the software component may include a first input configured to receive a first input data having two randomly-selected valid values, and invalid values, and the received input data may include the valid values of the first input data. The method may further include randomly selecting one of the valid values of the first input data in the received input data, and executing the software component by applying the received input data to inputs of the software component and the selected valid value to the first input of the software component, the execution of the software component providing an output data depending on the selected valid value.

Abstract: This disclosure relates to a method for securely performing a sensitive operation using a non-secure user terminal including: receiving and storing by the user terminal, software component data related to a set of a plurality of software components, each of the software components performing the sensitive operation and being protected against tampering and reverse-engineering; receiving by the user terminal, from a secure processor, an execution request to perform the sensitive operation; selecting, by the user terminal, one valid software component; executing, by the user terminal, the selected software component, which provides an output data; transmitting by the terminal to the secure processor, an identifier of the selected software component data a response of the sensitive operation, depending on the output, the sensitive operation being invalidated by the secure processor, when the received software component identifier corresponds to a software component set to invalid; and setting, by the user termin

Abstract: The disclosure relates to a method for authenticating a user from a user terminal, including receiving by the user terminal, from a secure processor, a software component protected against tampering and reverse-engineering and configured to generate random pixels having a probability lower than 100% to be visible in image frames, executing the software component by the user terminal, at a rate corresponding to a display refresh rate, to generate an image frame at the display refresh rate, displaying the generated image frames, which include machine unintelligible information formed of the random pixels, and becoming intelligible to a user at the display refresh rate, acquiring a response from the user in relation with the information, and transmitting by the user terminal the response to the secure processor, the user being authenticated when the response corresponds to the information and to a secret data shared by the user and the secure processor.

Abstract: This disclosure relates to a method for securely transmitting secret information to a user, including receiving by the user terminal, from a secure processor, a software component protected against tampering and reverse-engineering and configured to generate sets of adjacent pixels having a probability lower than 100% to be in a visible or invisible state, executing the software component by the user terminal, at a frame display refresh rate, to generate the pixel sets at the display refresh rate, inserting the pixel sets generated by each execution of the software component into one respective image frame, and activating display of the image frames at the frame display refresh rate, the image frames including information which is machine unintelligible as being formed of the pixel sets, the information becoming intelligible to a user at the display refresh rate based on a human visual system.

Abstract: This disclosure relates to a method for authenticating a user, including: receiving from a secure processor, a software component configured to generate an image frame including random pixels having a probability lower than 100% to be visible in the image frame; executing the software component a plurality of times to generate a plurality of image frames; displaying the plurality of image frames at a frame display rate, the image frames including information which is machine unintelligible as being formed of the random pixels, the frame display rate being such that the information becomes intelligible to the user, the information specifying a biometric challenge to enter by the user; acquiring biometric data from the user; and transmitting the biometric data to the secure processor.