Encrypting-decrypting method based on AES algorithm and encrypting-decrypting device

Abstract

The invention relates to a method for coding and decoding, based on AES algorism. Wherein, it comprises that a, based on the key length, fixing the literate time Nr; b, initializing the data, before first literating the input data, treating it with key operation on it with sub key; c, loading coding or decoding control signal; d, under the control of coding control signal, the decoding / coding literate complex module processes Nr literate operation for Nr times, and under the control of decoding control signal, said module processes decoding literate for Nr times. The invention also provides a relative decoder or coder, which comprises a decoding / coding literate complex module. The invention has a circuit which can simplify the AES algorism, with low power consumption and cost.

Description

technical field [0001] The invention relates to the technical field of data communication security, in particular to an encryption and decryption technology. Background technique [0002] The AES algorithm is the abbreviation of Advanced Encrypt Standard, which is a new symmetric key encryption algorithm standard announced by the American National Standards Committee NIST. The AES algorithm has the advantages of wide application range, short waiting time, easy concealment, and high throughput. Therefore, the AES algorithm is applied in more and more security fields. [0003] As a new symmetric key encryption algorithm standard that replaces the Data Encryption Standard (DES), the AES algorithm is an iterative block cipher algorithm with a block length of 128 bits and a key length that can be specified as 128 bits, 192 bits or 256 bits. The key iteration of the AES algorithm consists of three reversible transformations called layers, which are linear mixing layer, nonlinear ...

AI Technical Summary

Problems solved by technology

Taking the input as a 128-bit key as an example, if the parallel algorithm is executed, 20 S-box permutations and 16 S-box inverse permutations are required, that is, a total of 36 16×16 lookup tables are required, which requires a lot of effort in design large area overhead

[0014] Second, the existing AES algorithm mixed column transformation (MixColumn) and mixed column inverse transformation (InvMixColumn) use a separate unit for operation, so that encryption and decryption need to use different modules, which is not conducive to the realization of AES modularization, More direct increase in area overhead

This method will also cause a large area overhead when the circuit design is implemented. For example, for a 256-bit key, a 14×128-bit key storage unit is required

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