Implementation mode of extensible format preserving encryption method

Abstract

The invention provides an implementation mode of an extensible format-preserving encryption method, which comprises the following steps: firstly, judging the type of a field to be encrypted in a usersensitive information database, determining whether the field belongs to a common message space or not, and if so, according to a character set identifier of data, acquiring a specific character set in a common message space defined in the program in advance; and if not, expanding a new message space, and obtaining a newly-added character set; mapping plaintext character strings needing to be encrypted through the character sets obtained respectively, and encoding the plaintext character strings into plaintext numeric strings; encrypting to obtain a ciphertext numeric string; and finally, selecting a character set of the message space according to the character set identifier, and performing inverse mapping on the encrypted ciphertext numeric string to obtain ciphertext character strings with the same format, thereby finishing encryption. By defining and configuring the message space, the configurable and extensible FPE message space is realized, the new message space does not need tobe adapted by modifying a bottom layer code, and the practicability of the FPE encryption method is improved.

Description

technical field [0001] The invention belongs to the field of data encryption, and in particular relates to an implementation of an extensible format-preserving encryption method. Background technique [0002] With the rapid development of computer technology and network technology, the security problem of sensitive information leakage is becoming more and more serious. The most fundamental way to protect sensitive information is to encrypt it through cryptography. However, in structured encryption and decryption application scenarios such as databases, encryption using traditional block ciphers usually expands data, changes the length and type of data, and leads to modification of the database structure and application programs. [0003] In response to the above problems, Spies proposed a format-preserving encryption technology. Format-Preserving Encryption (FPE) is an emerging branch in the field of information security and privacy protection. It is a new type of encrypti...

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Problems solved by technology

[0005] According to the principle of FPE encryption, the implementation of the FPE method depends on a message space. Since the message space is uncertain, different encrypted objects have different message spaces. Therefore, if you want to perform FPE encryption on a new encrypted object, you need Modify the underlying code to adapt to the new message space, which brings great inconvenience to the practicability of FPE

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