Differential hashing functions: application to reachability graph generation

The paper presents the differential hashing functions. A differential computation process enables hashing function processing time to be optimized. After a formal definition of the differential property for hashing functions, we show that not all hashing functions have this property, then we propose a characterization of the differential hashing function set. Next, we show the performance acceleration produced by the differential algorithms applied to five hashing functions found in common applications. The observed accelerations can be significant because they are proportional to key length. Last we study the performances of a differential hashing function for the reachability graph exploration of distributed systems specified by a Petri net. This application demonstrates the advantages and the limits of the differential technique