Complexity Evaluation of Knapsack Crypto System using Fuzzy Set

It is well known that the knapsack cryptosystem is a type of public key cryptosystems. It is based on the well known mathematical concept, i.e., the choosing of one way function. Many Knapsack cryptosystems were invented in the last 20 years, and many attacking methods were invented as a counterattack against the developed knapsack cryptosystems. All the attacking methods aim towards breaking the security of the considered system. But, sometimes, the designer needs to know the level of security ( complexity ) of the new designed knapsack cryptosystem, or she / he needs to know what the advantage given by any development performed on any known knapsack cryptosystem. Hence she / he must look for an evaluation criteria that can be used as an evaluation method or ( procedure) . Till now the field of security evaluation is considered as new field. Most of interesting experts consider it as apart of cryptanalysis. Four years ago Fuzzy logic evaluator was used for the first time as a complexity evaluator for stream cipher system. This paper considers the Fuzzy logic evaluation method against another type of cryptosystem , that is knapsack cryptosystems. Two input variables are taken into consideration, and according to them the complexity evaluator based on Fuzzy logic was designed and simulated. Many knapsack cryptosystems were tested by this evaluator like (Luli system, Chor Rivest, Traditional and Advance Adina Diparto Systems). The results were promising