基于截断表的保留格式加密算法TT-FPEOA北大核心

Format-preserving encryption(FPE)algorithms can encrypt data while ensuring that the plaintext and ciphertext have the same format.This addresses the problem of privacy leakage caused by storing sensitive data in plaintext,such as credit card numbers,phone numbers,and ID numbers.Current FPE algorithms are mostly extended and improved based on prefix,cycle-walk-ing,and generalized-Feistel algorithms,and face issues with the uncertainty of multiple calls to the cycle-walking structure.Additionally,existing format-preserving encryption algorithms have certain limitations in terms of the problem domain they address.This paper proposes a novel format-preser-ving encryption algorithm based on a truncated table,which requires only a single call to the cycle-walking structure,ensuring that the encryption result falls within the problem domain.Furthermore,based on the truncated table algorithm,a segment-based processing scheme is proposed,which fur-ther expands the problem domain that the format-preserving encryption algorithm can address.Secu-rity analysis shows that our proposed protocol is secure against malicious adversaries.Experimental results demonstrate that the proposed algorithm is highly efficient,reducing the number of repeated calls to the cycle-walking structure in the format-preserving encryption process to zero.In compari-son with previous format-preserving encryption algorithms,the average encryption overhead per byte is comparable.