Abstract: A method of administering a network comprises the steps of: detecting the occurrence of a triggering event alerting an administrator to the presence of a user entity on the network, the triggering event being selected from the group consisting of: (i) allocation of a network address to the user entity; (ii) alteration of the user entity's network address; (iii) an action by the user entity causing resolution between a network address and an identifier; (iv) association of the user entity's network address and an identifier. Upon detecting such an event, the user entity having the network address is scanned for vulnerabilities by sending at least one outward packet to it, for example seeking to establish a connection on a particular port, and the response, if any, is then used to determine whether is vulnerable to known malicious code.

Abstract: Access to a data processor is controlled by determining if a requested function command conforms to a set of parameters, the set of parameters being derived from previously executed function commands. If the requested function command does not conform to the set of parameters the data processor is controlled to temporarily hold the execution of the requested function commands.

Abstract: Control of access to data within a first data processing device is provided. The data processing device contains at least one data item which has a use policy associated with it. In response to a request from or a requirement of a second data processing device to perform an operation on the data item, the first data processing device seeks information about the ability of the second data processing device to respect conditions specified in the policy and on the basis of a comparison between the policy and the ability of the device to satisfy the policy, the first data processing device decides whether to allow the operation to be performed.