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Acyclic network of checker should favour input dependent functions as checkees #39

Closed mr-ma closed 6 years ago

mr-ma commented 6 years ago

In theory, an acyclic directed graph with n nodes can maximum have (N-1)(N)/2 edges. The root of the graph is not checked by other nodes. Conversely, the last node does not check any other nodes. To expand the protection coverage, modify the function mapping on networks such that input dependent functions are assigned to nodes other than the root node. Create a sorted list of functions, in which the input independents appear first, whereas input dependents appear at the end of the list. The mapping shall start from the beginning of the function list and assign them to the graph (starting from the root node).

mr-ma commented 6 years ago

To maximise OH protection, we need to control the number of input independent functions that are used as checkee in SC. For this purpose, we introduce a parameter as maximum-percentage-of-input-independents say M in SC. In the SC pass we honour this parameter by randomly selecting M percent of input independent functions to be used in the root of the protection network.

mr-ma commented 6 years ago

Sorting by input independent functions (as detailed in comment 1) results in significant overhead! We should keep the randomness there (as in the second comment) and limit the number of input independent functions protected by SC with the M parameter.