Method and device for realizing Shield block cipher generated by novel secret key and readable storage medium

Abstract

The invention discloses a method and a device for realizing a Shield block cipher generated by a novel secret key, and a readable storage medium. According to the method, the Shield grouping length isdesigned to be 128 bits, a secret key is any length, an encryption round function is based on an SPN structure, and the encryption sequence is round secret key addition, S box replacement, row shifting and column hybrid transformation in sequence. The secret key expansion function divides an original secret key into three parts, generates three round secret keys by using a hash function MD5, anduses the round secret keys in different rounds of addition operation. According to the S box replacement transformation, 128-bit data replacement transformation is carried out by adopting two 4 * 4 Sboxes; the data are divided into 32 4-bit units; and along with the change of encryption / decryption rounds, the data units respectively carry out corresponding S box increasing / decreasing replacementoperation. According to the invention, the occupied area resource of the Shield cipher is small; the storage space for storing the original secret key is reduced; and the known attack can be well resisted by increasing the length of the secret key and expanding the secret key space.

Description

technical field [0001] The invention relates to a novel key generation Shield block cipher realization method, device and readable storage medium. Background technique [0002] In recent years, the development of supercomputers in the world has been advancing by leaps and bounds. Its computing power has been showing exponential growth in recent years. The security of cryptographic systems and cryptographic algorithms has received serious impact. Using powerful computing power to carry out the most basic brute force attack method to crack the key of the password. The key length determines the number of possible keys, so increasing the key length increases the difficulty of cracking. After DES is cracked, the 3DES scheme is adopted to improve the security of the cryptographic algorithm by increasing the key length, while AES As for the encryption algorithm, the AES algorithm with a key length of 256 bits is used for encrypted transmission of highly confidential information. ...

AI Technical Summary

Problems solved by technology

[0005] The present invention provides a Shield block cipher implementation method, device and readable storage medium related to a new type of key generation. Attacks and the 8×8 fixed S-box occupying a lot of resources and other issues

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