Decryption method and system based on aes algorithm

Abstract

The present invention provides a decryption method and system based on the Aes algorithm. The method includes: receiving ciphertext, obtaining the corresponding original authentication label and key index; According to the Aes protocol rules, it is updated and stored in the standby initial vector memory to form a corresponding standby initial vector; according to the same Aes protocol operation logic, the first plaintext and corresponding to the current ciphertext are respectively obtained according to the parameters obtained above. The second plaintext, and obtain the corresponding first authentication label and second authentication label; according to the corresponding relationship between the first authentication label, the second authentication label and the original authentication label, confirm the output decryption result. The invention can correctly decrypt the back-to-back messages to be decrypted with the same key index, reduces the discarding probability in the decryption process of such messages, and does not affect the chip bandwidth while ensuring the security of the network messages.

Description

technical field [0001] The invention relates to the field of network communication, in particular to a decryption method and system based on an Aes algorithm. Background technique [0002] AES (Advanced Encryption Standard) is a symmetric block cipher algorithm released by the National Institute of Standards and Technology in FIPS PUB 197 in 2001. The Ethernet switching chip needs to perform encryption and decryption calculations on the input packets according to the Aes algorithm in the 802.1AE protocol to ensure information security. text) to decrypt the Aes algorithm, it is necessary to obtain the corresponding data from ivInfo (initial vector memory) and calculate iv (Initial Vector, initial vector) at the time of sop (Start of packet, start of packet), that is, when the message starts to be sent, The correct icv (Integrity Check Value, authentication label) is calculated at eop (End of packet), that is, at the end of the packet, and compared with the authentication lab...

AI Technical Summary

Problems solved by technology

Usually, in order to ensure high bandwidth, a pipeline method is used to implement; when using pipeline operations, there will be some special situations. When two back-to-back messages with the same key index need to be decrypted, the first message will be decrypted according to the key index. Get the corresponding initial vector and calculate the corresponding authentication label at eop. If the eop of the first packet has not arrived yet, the second packet has already entered the pipeline for decryption. At this time, the second packet needs to Get your own initial vector, but the authentication label calculation of the first package is not yet completed, so the initial vector obtained by the second package is the old value, at this time the decryption of the second package will be wrong, resulting in back-to-back The second packet is dropped

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