Abstract
<title>Abstract</title> <p>The rapid growth of digital information exchange across cloud platforms, industrial infrastructures, academic environments, and governmental systems has increased the demand for cryptographic techniques capable of providing secure and efficient protection for binary data. This paper presents a scalable hybrid encryption framework that integrates the Unimodular Hill Cipher (UHC) with a chaotic Logistic Map-based XOR stream cipher to achieve format-independent binary file encryption. The proposed framework combines the strong diffusion characteristics of unimodular matrix transformations with the nonlinear confusion introduced by a chaotic keystream generated from the logistic map. Unlike many existing approaches that are primarily designed for image encryption, the proposed method directly encrypts arbitrary binary files as raw byte streams without requiring any format-specific preprocessing. The proposed scheme was evaluated using twelve binary files in DOCX, PDF, and JPEG formats with file sizes ranging from 1 MB to 100 MB. Security performance was analyzed through Shannon entropy, correlation coefficient, histogram distribution, chi-square test, avalanche effect, differential analysis, key sensitivity, and MD5-based integrity verification. Experimental results show that the encrypted files achieve an average entropy of 7.9999 and an average correlation coefficient of − 0.0043, indicating near-ideal randomness and negligible statistical dependence. For PDF datasets, the proposed method achieved an avalanche effect of 50.0020%, key sensitivity of 99.6139%, and a chi-square p-value of 0.967092, demonstrating strong diffusion and high resistance to statistical attacks. Performance evaluation further indicates average encryption and decryption throughputs of 24.48 MB/s and 23.83 MB/s, respectively, while maintaining linear scalability as file size increases. Moreover, all decrypted files produced identical MD5 hashes to their original counterparts, confirming complete lossless recovery. These findings demonstrate that the proposed hybrid UHC–Logistic XOR framework effectively balances security, computational efficiency, scalability, and compatibility across diverse binary file formats.</p>