Key transportation

1. A system for enabling authenticated communication between a first entity and at least one other entity, the system including a second entity and a processor, wherein:

the first entity and the second entity share transport keys; and

the second entity includes at least one variant authentication key configured to be transported from the second entity to the first entity using the transport keys under control of the processor, the variant authentication key being a variant key of a base authentication key included in the at least one other entity generated by applying a one way function to the base authentication key and a first bit-pattern stored in the at least one other entity and being usable to enable the authenticated communication by the first entity with the at least one other entity, the first entity being configured to use common signature generation using the transport keys to receive the variant authentication key from the second entity,

wherein the first entity and the second entity have the same identifier which is used to generate the variant authentication key.

2. A system according to claim 1 , wherein each of the transport keys is a second bit-pattern stored in the first and second entities during manufacture of the system or its components.

3. A system according to claim 2 , wherein the second bit-pattern was determined randomly or pseudo-randomly.

4. A system according to claim 1 , wherein the variant authentication key enables authenticated communication between the first and second entities.

5. A system according to claim 4 , wherein the variant authentication key provides the first entity with permission to request performance of at least one operation on at least one value in the second entity.

6. A system according to claim 1 , wherein the variant authentication key is a third bit-pattern that was determined randomly or pseudo-randomly.