Research And Application Of Express Information Encryption Based On Improved AES And QR Code

With the rapid rise of e-commerce,the express industry is showing unprecedented prosperity.In the transit transportation Express stage or the stage when users discard the express box after taking the express,the express orders with plaintext divulges a large amount of private information of express users,threatening their information security.On the other hand,the overly simple method of"receiving express delivery verbally"leads to the existence of the phenomenon of pretending to receive express delivery,and this type of stealing express delivery has caused property losses of express delivery users.Quick Response Code(QR Code is the most widely used two-dimensional code at present.Advanced Encryption Standard(AES is a standard encryption algorithm selected on a large scale in the technical field,so it is also an ideal algorithm for encrypting the plaintext information of express users.this thesis is committed to further improving the security and efficiency of AES,and applies encryption technology combined with QR Code technology to the express industry to protect the information security and property security of express users.The main research work is as follows:(1)AES has Padding Oracle vulnerability in CBC mode.This thesis improves the padding rule of plaintext packets in AES to prevent the generation of padding error from the root,The vulnerability is repaired.Experiments show that the ciphertext of the improved AES is modified bit by bit,and the modified results meet the requirements of the new padding rule.Therefore,the server can not get Oracle information to conduct side channel attack.The improved AES is more secure.(2)AES original key expansion algorithm has the disadvantage of too strong correlation between key words.In order to weaken the correlation between round keys,while retaining the immediacy of the key expansion algorithm,this thesis divides the generation of the ten rounds of keys K₁ K₁₀ into two parts.The first-round key K₁ is obtained based on the initial key K₀.The last nine rounds of keys K_i mainly obtained through the first two rounds of keys(K_i-1 and K_i-2.Theoretical analysis shows that the number of guesses needed to crack K₀ or K₁ is 2⁹⁶,and the difficulty of cracking K _i(2?i?1 0)is the same as the exhaustive strength,which further improves the security of the AES.Experimental results show that the improved algorithm generates ten rounds of keys 2.4 times faster than the original algorithm.(3)The improved AES from the above two aspects is implemented by Python.The avalanche-effect experiments show that the improved AES has higher security.The time efficiency comparison experiments show that the improved AES increases the encryption time by 4.26%and the decryption time by 4.75%.Based on the improved AES and QR Code technology,"AES Encryption System"and"AES Decryption System"are developed,and this thesis puts forward a new way of sending and receiving express.The encryption system encrypts the plaintext information of express users to obtain the ciphertext QR Code,which protects their information security.The decryption system verifies the identity of the recipient to prevent pretending to receive the express and reduce the property loss of users.Encryption and decryption systems have high practical value.