Are Social Networks Watermarking Us or Are We (Unawarely) Watermarking Ourself?

TL;DR

This paper investigates how social networks handle image watermarking, tests the robustness of various algorithms on these platforms, and proposes a PRNU-based method for authorship verification that remains effective despite image downgrades.

Contribution

It provides a comprehensive analysis of social networks' treatment of images, evaluates watermarking algorithm robustness, and introduces a PRNU-based approach for reliable authorship attribution.

Findings

PRNU-based method is robust against image downgrades on social networks.

Proposed watermarking technique outperforms existing methods in accuracy.

Analysis of 8,400 images demonstrates practical applicability for privacy and security.

Abstract

In the last decade, Social Networks (SNs) have deeply changed many aspects of society, and one of the most widespread behaviours is the sharing of pictures. However, malicious users often exploit shared pictures to create fake profiles leading to the growth of cybercrime. Thus, keeping in mind this scenario, authorship attribution and verification through image watermarking techniques are becoming more and more important. In this paper, firstly, we investigate how 13 most popular SNs treat the uploaded pictures, in order to identify a possible implementation of image watermarking techniques by respective SNs. Secondly, on these 13 SNs, we test the robustness of several image watermarking algorithms. Finally, we verify whether a method based on the Photo-Response Non-Uniformity (PRNU) technique can be successfully used as a watermarking approach for authorship attribution and verification of pictures on SNs. The proposed method is robust enough in spite of the fact that the pictures get downgraded during the uploading process by SNs. The results of our analysis on a real dataset of 8,400 pictures show that the proposed method is more effective than other watermarking techniques and can help to address serious questions about privacy and security on SNs.