The invention relates to systems for secure interrupt handling, a method for verifying a priority of a winning service request node and a method and an apparatus for verifying integrity of service requests.In accordance with an aspect of the invention, there is provided a method for verifying a priority of a winning service request node (SRN) established in an arbitration between a plurality of service request nodes (SRNs) performed by an interrupt controller, the method comprising: storing the priority of the winning SRN in the interrupt controller; encoding the priority of the winning SRN, wherein the encoding allows for error detection; transmitting the encoded priority from the winning SRN to the interrupt controller; and verifying the priority of the winning SRN by comparing the encoded priority transmitted by the winning SRN with the priority of the winning SRN established in the arbitration and stored in the interrupt controller.