Attacking Models Of Hashing Function Based On Grover’s Search Algorithm

Hashing function is one of the important algorithms which can be used in digitalsignature, using quantum computation theory to analyze the safety of hashing algorithmis a hot issue in the field of quantum cryptography and information security. The thesishas done some research on key issues of attack models of hashing function based onGrover’s search algorithm, and made some achievements.By analyzing the general attacking model of hashing function based on Groversearch algorithm, the thesis focuses on the attack model of MD5algorithm, andanalyzes the effect of the number of solutions to target iterative times and the searchprobability of success.For the only ciphertext attack, giving a crack model, according tothe known plaintext attack, giving an improved collision model, so that the main idea ofthe crack model and the improved collision model becomes similarly. Then for eachmodel, the quantum circuit is clearly designed.Finally, by using the multithread programming of CUDA to simulate the crackmodel of MD5, the experiment result shows that the crack model and collision model inthis thesis is effective. The research achievement has played an important theoreticalsignificance and practical value on analyzing the resistance of hashing function toquantum computing, and in the research and application of the digital signature.