Abstract: A method of multi-domain authorization/authentication on a computer network comprises: a user making a request to a policy enforcement point of a computer for access to information on the computer; providing a location address for a user's authorization and/or authentication information, a policy decision point of the service on the computer network then verifying the authorization/authentication information; and the user being given access by the PEP to the information or the service requested, if the request is accepted, wherein the user's authorization/authentication and/or further information is located on a meta policy decision point (MPDP).

Abstract: A network gateway (1005) is described, wherein an object invocation (1020) containing an embedded object reference (1025), which points to a further object (1002), is modified on passing through the gateway. The gateway validates the object invocation and enacts a number of security tests thereon before forwarding it on. In preferred embodiments, the embedded object reference is replaced by an object reference (1035) to a gateway proxy specifically for the further object (1002). The replacement object reference (1035) also includes enough information that the original object reference (1025) can be recovered. The gateway proxy is generated on or after receipt of the invocation (1020). In the event the further object (1002), which was the subject of the object reference, is itself invoked, the invocation is directed to the gateway proxy, which in turn recovers the original object reference and forwards the invocation on to the further object (1002).

Abstract: A method of multi-domain authorisation/authentication on a computer network comprises: a user making a request to a policy enforcement point of a computer for access to information on the computer; providing a location address for a user's authorisation and/or authentication information, a policy decision point of the service on the computer network then verifying the authorisation/authentication information; and the user being given access by the PEP to the information or the service requested, if the request is accepted, wherein the user's authorisation/authentication and/or further information is located on a meta policy decision point (MPDP).