密码学报（中英文）2025，Vol.12Issue(4)：766-779,14.DOI:10.13868/j.cnki.jcr.000793
调整因子加密的可变轮保留格式加密方案TEVR-FPE
TEVR-FPE:Tweak-Encrypted Variable-Rounds Format-Preserving Encryption
摘要
Abstract
Format-preserving encryption(FPE)ensures that the plaintext and the ciphertext have the same format;ciphertexts share the same domain as plaintexts.FPE has important applications in the field of de-identification of personal information.It is widely used to construct FPE based on the generalized Feistel structure combined with a tweakable block cipher.For this kind of mecha-nism,Bellare et al.proposed a general attack exploring the freedom of choosing tweaks used by the tweakable block cipher.In addition,for FPE mechanisms such as FF3 and FF3-1,the mechanisms' security can be significantly weakened when attacks choose tweaks with special formats.In order to achieve the required security level,ANSI X9.124-1 requires to encrypt small messages with multiple FPE encryptions cyclicly.Tweak-encrypted variable-rounds FPE(TEVR-FPE)enhances FF3-1 with five security improvements,including adaptively selecting the number of rounds based on the length of the plaintext message,encrypting the padded tweak and incorporating the resulting ciphertext into the round function for messages up to 112 bits,and ensuring that the right segment is at least as long as the left during message segmentation,thus increasing the complexity of full message recovery at-tacks.Analysis shows that TEVR-FPE effectively resists known attacks.Furthermore,under specified security requirements,TEVR-FPE outperforms multiple encryptions of FF1 or FF3-1(as required by X9.124-1)across several commonly used message domains.关键词
FPE/FF1/FF3/FF3-1/Feistel结构/保留格式加密Key words
FPE/FF1/FF3/FF3-1/Feistel structure/format-preserving encryption分类
信息技术与安全科学引用本文复制引用
程朝辉,任飞..调整因子加密的可变轮保留格式加密方案TEVR-FPE[J].密码学报（中英文）,2025,12(4):766-779,14.基金项目
深圳市科技计划资助(KJZD20230923114405011)Shenzhen Science and Technology Program(KJZD20230923114405011) （KJZD20230923114405011）
