Method, system, medium, terminal and an application for realizing format preserving encryption

Abstract

The invention belongs to the technical field of passwords, and discloses a method, a system, a medium, a terminal and an application for realizing format preserving encryption, an FPE algorithm is combined with a national cryptographic SM4 algorithm, and the randomness and irreversibility of an original permutation table are ensured by using the security of SM4; a new replacement table is derived through ciphertext control, so that each character in a database field corresponds to one new replacement table, and differential attack prevention is realized; the characters are encrypted and decrypted by looking up the table; the system for realizing format keeping encryption comprises an algorithm combination module, a differential attack prevention module and a character encryption and decryption module. According to the method and the system for realizing format preserving encryption provided by the invention, a new FPE algorithm is constructed based on a national cryptographic SM4 algorithm, and the fundamental requirement that the algorithm is completely autonomous is met. Meanwhile, according to the method and system for achieving format keeping encryption, the replacement table is constructed based on the ciphertext, and differential attacks based on the replacement table are effectively destroyed.

Description

technical field [0001] The invention belongs to the technical field of encryption, and in particular relates to a method, system, medium, terminal and application for realizing format-preserving encryption. Background technique [0002] In recent years, relevant state agencies and departments have proposed to promote national secret algorithms and strengthen network security construction from the long-term perspective of national security strategy. Cryptographic algorithm is the core technology to ensure information security. Especially in the era of big data, a large amount of sensitive data of users is stored in the databases of financial, e-commerce, medical and other industries. Once the information is stolen, it will cause fatal damage. So how to ensure The information security of the database is an important subject. The Format Preserving Encryption (FPE) method is currently the best way to encrypt database fields, because in actual application scenarios, using existi...

AI Technical Summary

Problems solved by technology

[0005] (1) The State Cryptography Administration does not have a unified format-preserving encryption technology standard specification. The format-preserving encryption method proposed by NIST is not used in many domestic information systems, and the FPE algorithm confirmed by the State Cryptography Administration is very limited.

[0006] (2) The security of the prior art should be equivalent to that of block ciphers, and the security of short plaintext data cannot be reduced; at the same time, the encryption speed of FPE is significantly slower than that of block ciphers

[0009] Solving the Limited Diffusion of Ciphertext Errors in Cryptographic Algorithms

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