In a method of authorizing a supply for use with a printing system, a supply is provided having a memory containing a first and second codes and supply-specific data, which uniquely identifies the supply. The first code, the second code and the supply-specific data are retrieved from the memory of the supply. The first and second codes are translated using the supply-specific data. The translated first code is compared to a third code and the translated second code is compared to a fourth code. Use of the supply with the printing system is authorized when the translated first code corresponds to the third code and the translated second code corresponds to the fourth code. Use of the supply with the printing system is prevented when either the translated first code does not correspond to the third code, or the translated second code does not correspond to the fourth code.