Abstract: A method of printing digital data on a photograph includes loading an image processing program, transforming image data with the image processing program to produce transformed image data; redundantly encoding the transformed image data and the image processing program into a distributed form; and printing the redundantly encoded data using an invisible ink on a surface of a print media while simultaneously printing out the transformed image data as a photographic image in a visual, human readable form on the same surface of said print media. The redundantly encoded data is distributed across the print media such that the encoded data may be read and decoded despite a partial obliteration of the encoded data.

Abstract: A card for causing the device to operate in a predetermined operation mode. The card comprises, on a first surface, a visual representation of the operation mode, and on a second surface, a visually encoded representation of the operation mode. The encoded representation is readable and decodable by the device so as to cause the device to operate in the operation mode. Methods of determining an output data of sensed data are also disclosed.

Abstract: A card for causing the device to operate in a predetermined operation mode. The card comprises, on a first surface, a visual representation of the operation mode, and on a second surface, a visually encoded representation of the operation mode. The encoded representation is readable and decodable by the device so as to cause the device to operate in the operation mode. Methods of determining an output data of sensed data are also disclosed.

Abstract: This invention is a validation method for determining whether an untrusted chip is valid, or not. In another aspect it concerns a validation system for the method. The method may be used to determine the physical presence of a valid chip. A trusted chip generates a random number and a digital signature for it, encrypts them with a first key and then calls a prove function in the untrusted chip. The prove function decrypts the random number and signature, and calculates another signature from the decrypted random number, for comparison with the decrypted one. If the comparison is successful the random number is encrypted with another key and sent back as a second number. Finally, a test function is called in the trusted chip to generate its own encrypted version of the random number using the second key and then compare it with the received version to validate the untrusted chip. The untrusted chip may be associated with a consumable so that validation of the untrusted chip authenticates the consumable.

Abstract: A card for causing the device to operate in a predetermined operation mode. The card comprises, on a first surface, a visual representation of the operation mode, and on a second surface, a visually encoded representation of the operation mode. The encoded representation is readable and decodable by the device so as to cause the device to operate in the operation mode. Methods of determining an output data of sensed data are also disclosed.