1. In a domain comprising a plurality of devices, the devices in the domain sharing a common domain key, a method of enabling an entity that is not a member of the domain to create an object that can be authenticated and/or decrypted using the common domain key, the method comprising providing to the entity that is not a member of the domain a diversified key that is derived using a one-way function from at least the common domain key for creating authentication data related to said object and/or for encrypting at least part of said object, and authenticating and/or decrypting said object using the diversified key.