Abstract: A method of storing a first bit-pattern in non-volatile memory of a device, the method comprising: (a) applying a one way function to a second bit-pattern associated with the device, thereby to generate a first result; (b) applying a second function to the first result and the first bit-pattern, thereby to generate a second result; and (c) storing the second result in the memory, thereby indirectly storing the first bit-pattern.

Abstract: A method of enabling or disabling a verification process of a first entity in response to a predetermined event, the first entity having at least one associated bit-pattern and at least one variant key, each of the variant keys having been generated by applying a one way function to: a base key; and one or more of the at least one bit-patterns, respectively; or one or more alternative bit patterns, each of the alternative bit-patterns being based on one or the at least one bit-patterns, the method including (a) determining that the predetermined event has happened; and (b) enabling or disabling at least one of the first variant keys in response the predetermined event.