Research On Application Of Key Security Based On Wireless Channel Protocol

While bringing convenience to users,wireless network protocols have also shown their inherent security breaches,which can be exploited to gain unauthorized access to networks and encrypted communication data.In 2017,attackers discovered a security breach in the WPA2 protocol by resetting the keys and random numbers needed for the encryption algorithm through an attack called Key Reinstallation Attack(KRAK),resulting in the same keys and random numbers being used multiple times when the WPA2 protocol is encrypted using the AES algorithm,allowing attackers to decrypt the ciphertext.The KRAK attack demonstrates the neglect of key security behavior by designers when designing encryption algorithms and protocols,and therefore,the key security behavior in wireless channel protocols needs to be investigated.First,this thesis proposes an improvement method of AES algorithm,which reduces the correlation between round keys by designing a key arrangement algorithm.Without affecting the execution efficiency of the algorithm,the original algorithm is improved by introducing chaotic random sequences and a new table of round constants.In order to reduce the correlation of key words two key arrangement methods are designed separately,which reduce the problem of strong correlation of the original algorithm in the first and second rounds of round key words,respectively,and finally the new encryption method is obtained by combining the improved round functions.Secondly,this thesis proposes a method of impossible differential fault attack on AES algorithm.A 3-round impossible differential distinguisher is designed by studying the principle of impossible differential analysis,a 6-round impossible differential analysis path is designed based on this distinguisher,and finally a lowround impossible differential fault attack method on AES algorithm is proposed based on a single-byte random fault induction model.The method uses the false key candidates generated in the differential fault attack to screen out the false keys on the impossible differential path,and then achieves the low-round impossible differential analysis of the AES algorithm,which poses a greater threat to the original key scheduling algorithm.The experimental part consists of three parts: the first part is the key generation test of the round key generation of the key arrangement method to verify its security;the second part is the efficiency and security test of the encryption algorithm to test the execution efficiency and randomness of the improved algorithm for encryption and decryption in different ways and compare it with the original algorithm to determine its actual effectiveness;the third part is the experiment of differential fault attack in which the number of different erroneous ciphertext pairs and the number of attacks on the amount and probability of the generated erroneous key candidates are consistent with the theoretical analysis to verify the theoretical correctness of the attack method.The experimental results show that: in the best case,the round key generated by the key arrangement method proposed in this thesis already has the characteristic of weak correlation that the original algorithm can only have in the third round in the first round,the execution efficiency of the algorithm is basically the same as that of the original algorithm,and the randomness test results show that the ciphertext sequence generated by this algorithm has good random performance,which proves the high security performance and feasibility of this algorithm;meanwhile,the same results as the theoretical analysis are obtained through the fault attack experiment,which verifies the correctness of the attack scheme proposed in this thesis.