Format-reserved encryption algorithm based on multi-segmented Feistel network

Abstract

A format-preserving encryption algorithm based on a multi-segmented Feistel network, the method includes the following steps: S According to its own format, it is divided into t part: S ₁ ,S ₂ ,…,S _t . where set S _i is of size n _i . Set the number of rounds for the Feistel network r and the key used by the round function k , where the number of rounds r for the number of divisions t associated even numbers; for a given plaintext m , format it as: m=x ₁ || x ₂ || … || x _t ,in: x ₁ ∈ S ₁ ,x ₂ ∈ S ₂ ,…,x _t ∈ S _t ;Will x ₁ ,x ₂ ,…,x _n as t Segmentation of the Feistel network t input, or input as ;Execute r rounds of round operations, and the final output ciphertext is c=y ₁ || y ₂ || … || y _t ,in: y ₁ ∈ S ₁ ，y ₂ ∈ S ₂ ，…，y _t ∈ S _t , the advantages of the present invention are: by segmenting the sensitive data and defining the value domains of different segments, using self-defined pseudo-random functions, modulus addition and modulus subtraction operations, and using Feistel network to perform even-numbered rounds of round operations to achieve Encryption that preserves the format can support numerical data encryption schemes that retain any given format. After encryption, the data and database will not be affected, which provides the possibility for the encryption protection of numerical personal identification information in existing database application systems.

Description

technical field [0001] The invention belongs to the field of data encryption, and in particular relates to a numerical encryption method that retains any given format. The method can be applied in environments (databases, networks, smart card virtual machines, etc.) that require encryption of sensitive information. Background technique [0002] The rapid development of the Internet makes sensitive data in storage media (databases, mobile devices, smart cards, etc.) more and more easy to be stolen. The most effective way to secure your sensitive data. Sensitive data often contains its own fixed format, such as ID number, bank card number, etc. However, traditional encryption algorithms, such as AES, 3DES, etc., will destroy the format of the data, so that the encrypted data cannot be stored in the original database or node, and will destroy the functions of the existing business system. How to encrypt this information without destroying its inherent format, so as to ensure ...

AI Technical Summary

Problems solved by technology

[0003] The purpose of the present invention is to solve the problem that the traditional encryption algorithm will destroy the format of the data, so that the encrypted data cannot be stored in the original database, mobile device or smart card and other storage media, and provide a format-preserving encryption method for sensitive data

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