A digital camera includes an image capturing assembly for capturing an image and generating image data. Processing circuitry is connected to the image capturing assembly for receiving the image data, processing the image data and generating print data. A printer is connected to the processing circuitry to receive the print data, the printer being connectable to a consumable print roll to be validated, such that the processing circuitry is capable of communicating with the print roll. An authentication chip is connected to the processing circuitry and is configured to incorporate a random function that generates a random number when called by the processing circuitry and to apply a one-way function to the random number to generate a first value that is passed to the processing circuitry. The processing circuitry is configured to call a one-way function from the print roll that is configured to apply that function to the random number and to return a second value to the processing circuitry. The processing circuitry is further configured to compare the first and second values, thereby verifying the authenticity of the print roll.