In order to further study the application of deep learning in cryptographic security analysis,neural networks are used for differential analysis of lightweight block cryptography.The following four research results are obtained.First,a neural network differential distinguisher is constructed by using a deep residual network with an attention mechanism,and applied to three types of lightweight block ciphers:SIMON,SIMECK and SPECK.The results show that the effective distinguisher of SIMON32/64 and SIMECK32/64 can reach up to 11 rounds,and the accuracy is 0.5172 and 0.5164,respectively.The SPECK32/64 has an effective distinguisher of up to 8 rounds with an accuracy of 0.5868.Second,the influence of different input differences on the accuracy of the neural network differential distinguisher is explored.For SIMON,SIMECK and SPECK ciphers,the accuracy of the neural network differential distinguisher corresponding to different input differences is obtained by using the fast training of neural networks.The results show that the input difference with a low Hamming weight and high probability can improve the accuracy of the neural network differential distinguisher.At the same time,the suitable input difference for the SIMON32/64,SIMECK32/64 and SPECK32/64 neural network differential distinguisher is found to be 0x0000/0040,0x0000/0001 and 0x0040/0000,respectively.Third,the influence of the input data format containing different information on the accuracy of the neural network differential distinguisher is explored.Changing the amount of information contained in the input data according to the characteristics of the cryptographic algorithm and retraining the corresponding neural network differential distinguisher.The results show that,compared to a neural network differential distinguisher that only includes ciphertext pair information,those that incorporate both ciphertext pair information and differential information from the penultimate round achieve a higher accuracy.Fourth,on the basis of the above research,the last wheel key recovery attack is carried out on 11 rounds of SIMON32/64.When 29 plaintext-ciphertext pairs are selected,the attack success rate in 100 attacks can reach 100%.