Securing a transaction performed from a non-secure terminal

A user terminal configured to:

• receive from a secure processor, a software component configured to generate an image frame including information intelligible to the user, and a plurality of input data of the software component, the input data including a plurality of first input data each having two randomly-selected valid values and invalid values, the software component including a plurality of first inputs configured to receive respectively the first input data, the received input data including the valid values of the first input data;
• perform a plurality of times:
• selecting one of the valid values of each of the first input data in the received input data,
• 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 generating the image frame which has pixels in a visible or invisible state, depending on the selected valid values of the first input data and forming an image of the user intelligible information,
• displaying the image frame,
• acquiring, from the user, a response depending on the user intelligible information in the displayed image frame;
• and
• transmit the acquired response to the secure processor.

A computer program product loadable into a computer memory and comprising code portions which, when carried out by a computer, configure the computer to:

• receive from a secure processor, a software component configured to generate an image frame including information intelligible to a user, and a plurality of input data of the software component, the input data including a plurality of first input data each having two randomly-selected valid values and invalid values, the software component including a plurality of first inputs configured to receive respectively the first input data, the received input data including the valid values of the first input data;
• perform a plurality of times:
• selecting one of the valid values of each of the first input data in the received input data,
• 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 generating the image frame which has pixels in a visible or invisible state, depending on the selected valid values of the first input data and forming an image of the user intelligible information,
• displaying the image frame,
• acquiring from the user a response depending on the user intelligible information in the displayed image frame;
• and
• transmit the acquired response to the secure processor.