US 11,750,375 B2
Encryption and decryption method and device based on bit permutation and bit transformation
Yujuan Si, Guangdong (CN); Guanghui Feng, Guangdong (CN); Liuqi Lang, Guangdong (CN); Xiaoyang Fu, Guangdong (CN); and Hao Wu, Guangdong (CN)
Assigned to Zhuhai College of Science And Technology, Guangdong (CN); and Jilin University, Jilin (CN)
Appl. No. 17/428,405
Filed by Zhuhai College of Science And Technology, Guangdong (CN); and Jilin University, Jilin (CN)
PCT Filed Apr. 19, 2019, PCT No. PCT/CN2019/083409
§ 371(c)(1), (2) Date Jan. 5, 2022,
PCT Pub. No. WO2020/168629, PCT Pub. Date Aug. 27, 2020.
Claims priority of application No. 201910119852.5 (CN), filed on Feb. 18, 2019.
Prior Publication US 2022/0150054 A1, May 12, 2022
Int. Cl. G06F 21/00 (2013.01); H04L 29/06 (2006.01); H04L 9/08 (2006.01); H04L 9/00 (2022.01); H04L 9/06 (2006.01); H04L 9/14 (2006.01)
CPC H04L 9/0825 (2013.01) [H04L 9/001 (2013.01); H04L 9/0656 (2013.01); H04L 9/14 (2013.01)] 20 Claims
OG exemplary drawing
 
1. An encryption and decryption method based on bit permutation and bit transformation, comprising the following steps of:
S1: configuring a memory space, and preparing corresponding storage spaces for a plaintext file, a ciphertext file, and a key file, wherein an initial key file comes from a known coding sequence and serves as a shared file for encryption and decryption;
S2: changing a bit value of an initial key stream according to a bit operation rule, so as to obtain a bit-transformed key stream, and then changing a bit value of a plaintext according to the bit operation rule depending on the key stream; and
S3: on the basis of a bit-transformed plaintext stream, according to a bit permutation rule depending on the key stream, performing a bit permutation operation on the bit-transformed plaintext stream, and randomly distributing the plaintext stream in a ciphertext stream, so as to obtain a target ciphertext and store the target ciphertext as a file.