Grayscale-based Block Scrambling Image Encryption for Social Networking Services

TL;DR

This paper introduces a grayscale-based block scrambling encryption method that improves security for JPEG images in social media transmission by reducing color information and increasing block complexity.

Contribution

It presents a novel encryption scheme that allows smaller blocks, more blocks, and less color information, enhancing security against common attacks in social networking contexts.

Findings

Encrypted images successfully uploaded and downloaded from social media platforms.

The scheme effectively reduces color information, increasing security.

Experimental results demonstrate improved security features.

Abstract

This paper proposes a new block scrambling encryption scheme that enhances the security of encryption-then-compression (EtC) systems for JPEG images, which are used, for example, to securely transmit images through an untrusted channel provider. The proposed method allows the use of a smaller block size and a larger number of blocks than the conventional ones. Moreover, images encrypted using proposed scheme include less color information due to the use of grayscale even when the original image has three color channels. These features enhance security against various attacks such as jigsaw puzzle solver and brute-force attacks. The results of an experiment in which encrypted images were uploaded to and then downloaded from Twitter and Facebook demonstrated the effectiveness of the proposed scheme for EtC systems.