Abstract: A payload assurance system and method for a payload having a header which is to be transferred across a network boundary via at least one predetermined boundary control device. The system comprises at least one computer processor and at least one data storage device, arranged to provide an electronic authorisation token for authorising properties of the payload to be transferred, which electronic authorisation token comprsises at least one entropy element for ensuring that multiple electronic authorisation tokens authorising the same payload properties are unique. A boundary transfer assessment step may be provided at the network boundary, for indirectly determining whether the payload possesses the Authorisation token, using the payload header.

Abstract: A method and apparatus of payload assurance for a payload which is to be transferred across a network boundary via any of multiple predetermined boundary control devices, which may be grouped together, each having dedi¬cated permanent identity information. A first electronic entity provides an elec¬tronic authorisation token for defining properties of the payload, and an ephemeral ID array is determined in dependence upon the permanent identity information of each of the boundary control devices in the boundary control group and the authorisation token. An electronic release token is generated in dependence upon the ephemeral ID array and the authorisation token, to be forwarded to a second electronic entity, the release token being valid for use with the boundary control devices provided in the defined boundary control group.

Abstract: A data filter and a method of creating a network data pathway via a network filter is disclosed the method comprising a i. selection phase and ii. operation phase. The selection phase comprises transferring over a network at least one enquiry data packet between a first network user and at least one other network participant via the filter and receiving at least one enquiry data packet response from the at least one network participant via the filter. A network participant is selected so as to switch from the selection phase to the operation phase. The operation phase comprises creating a network data pathway between the first network user and the selected network participant and prohibiting further creation of a further network data pathway between the network user and any unselected network participant.

Abstract: The present invention provides a liquid hydrocarbon fuel composition comprising a major amount of a liquid hydrocarbon fuel and, as identifiable marker, a detectable amount of at least one C.sub.7-20 hydrocarbon containing at least one non-aromatic carbocyclic ring of at least 7 ring carbon atoms; and a method of modifying a liquid hydrocarbon fuel which comprises adding to the fuel, as identifiable marker, a detectable amount of at least one C.sub.7-20 hydrocarbon containing at least one non-aromatic carbocyclic ring of at least 7 ring carbon atoms.