Integrity checks used for security can also be used for error control .

Communication systems check integrity to protect information against alteration introduced by natural means such as noise and by malicious security attacks. This paper proposes that some integrity checks used for security should also be used for error control, since there are similarities between the functions used for both purposes, and repeated checking can have a high cost. The paper extensively examines where integrity functions should be implemented in a network, and the dependencies between functions implemented in a node, since these limit the extent to which such amalgamation of function is possible. The arguments presented in this paper mean that end-system-to-end-system (e.g. Transport layer) error checks will need to be cryptographically strengthened if they are to remain justifiable in the future.