1. A method of authenticating an object, the method including: sensing coded data provided on a surface associated with the object by an optical sensing device, the coded data being indicative of: a position on the surface; an identity of the object; and, a part of a signature, the signature being a digital signature of at least part of the identity; determining, by a processor and using the sensed coded data, a sensed identity and a sensed signature part; determining, by the processor and using the position, a sensed signature part identity; determining, by the processor and using the sensed identity, at least a determined signature; determining, by the processor and using the determined signature and the sensed signature part identity, a determined signature part; comparing by the processor the determined signature part to the sensed signature part; and, authenticating by the processor the object using the result of the comparison.