Research And Application Of Format-preserving Encryption Algorithm Based On National Secret

The opening and sharing of data resources is the core measure to release the value of data,but the following data mining and data analysis aggravate the risk of privacy disclosure,how to protect the privacy of users in the process of data analysis application has become a key problem to be solved in the field of data security.The format-preserving encryption can ensure that ciphertext and plaintext have the same format.It can not only provide data confidentiality protection,but also provide support for the statistics and analysis of ciphertext data.Based on the SM3 and SM4 algorithms of commercial ciphers in China,this paper studies the format-preserving encryption of numerical privacy data.First,we design a format-preserving encryption algorithm based on SM4,Then,combining with the SM3 algorithm,we design the authentication and preserving format encryption algorithm,Finally,the designed encryption algorithm is applied to the government data publishing scene,and experimental simulation is carried out.The specific research work is as follows:(1)The format-preserving encryption algorithm based on SM4 is proposed for numeric data.Firstly,according to the construction rules of characteristic plaintext data,the cycle-walking iterations are reduced;Secondly,the F-function in Feistel structure is designed by using block cipher algorithm SM4 and modular operation to realize the validity and validity of the ciphertext of characteristic data,and expand the application of SM4 algorithm of national secret;Finally,efficiency analysis and security analysis are carried out.The results show that compared with the traditional encryption algorithm,the algorithm improves the encryption efficiency and the availability of ciphertext data is higher.(2)The authentication and format-preserving encryption algorithm based onSM3/4 is proposed for numeric data.Firstly,based on SM4 algorithm and FF1 algorithm,a sub segment of the plaintext to be encrypted is divided into adjustment factors to realize the format-preserving encryption module;Then,the authentication module is realized by combining the results of each round of operation in the encryption module with the SM3 algorithm;Finally,the efficiency analysis and security analysis are carried out.The experimental simulation results show that compared with the current format-preserving encryption algorithm,the algorithm has tamper resistance,and the data has confidentiality and integrity while retaining the format.