Securing Digital Video

Advancements in internet technologies and compression methods have increased interest in digital video security over the past two decades. Techniques like watermarking, encryption, and scrambling have been explored, with encryption emerging as the most effective. Though total video encryption provides maximum security, its high space and time requirements limit widespread use. This study aimed to reduce space complexity in total video encryption using the Residue Number System (RNS). MPEG IV was used for compression, followed by encryption of pixel values with two RNS schemes. Reverse converters were applied for decryption. Sixteen videos in six formats were tested, alongside six existing cryptosystems, and results were compared using space complexity metrics. Findings showed a 47.03% reduction in file size after compression, successful encryption and decryption across formats, and significant space savings. The proposed schemes produced much smaller cipher sizes and reduced disk usage, although decrypted files increased in size. The study concludes RNS effectively reduces space complexity and recommends its use for secure video transmission and storage.