Abstract: The present disclosure relates to a guard system including a guard interface, a data guard, and a decider. The guard interface receives an access request relating to a data token, the access request including first information data representing a first information content. The data guard extracts an attribute relating to the information element from the information data and applies an access rule governing access to the data token to the extracted attribute to obtain a current verification result. The decider determines whether the current verification result matches a pre-stored verification result obtained from applying the access rule to a previously extracted attribute from a previous access request. If the current verification results does not match the pre-stored verification result, the decider outputs a warning message.