Abstract: A manifolded fail-safe hydraulic control system provides fail-safe operation of a pipeline valve using no more than a total of 45 proprietary parts in the system. The system controls the operation of a spring return actuator, which in turn strokes the pipeline valve from the normal operating position to the fail-safe position, or from the fail-safe position to the normal operating position. The system enables the valve to automatically stroke to its fail-safe position without external power.

Abstract: A certificate validation mechanism is provided for a network interface. The certificate validation mechanism maintains a certificate cache containing local copies of certificates with associated validity indications. The certificate validation mechanism is operable to compare a certificate associated with a received message to the certificate cache and, where the certificate associated with the received message is held in the certificate cache, to associate with the message an indication of validity retrieved from the certificate cache. By providing a cache for certificates local to the network interface, the need always to verify a certificate by reference to a public repository is removed. If a certificate is not held in the local cache, then it can still be necessary to query the public repository. Nevertheless, the verification mechanism provides more immediate verification of certificate validity as this can be made locally without the cost and time of the remote verification at the public repository.

Abstract: A method and system for routing messages comprising: converting a message received from a sender into an internal format comprising at least an attribute part and a data part, writing into said attribute part data extracted from said received message; and routing said converted message in dependence on the data in said attribute part.

Abstract: A certificate validation mechanism is provided for a network interface. The certificate validation mechanism maintains a certificate cache containing local copies of certificates with associated validity indications. The certificate validation mechanism is operable to compare a certificate associated with a received message to the certificate cache and, where the certificate associated with the received message is held in the certificate cache, to associate with the message an indication of validity retrieved from the certificate cache. By providing a cache for certificates local to the network interface, the need always to verify a certificate by reference to a public repository is removed. If a certificate is not held in the local cache, then it can still be necessary to query the public repository. Nevertheless, the verification mechanism provides more immediate verification of certificate validity as this can be made locally without the cost and time of the remote verification at the public repository.