CryptoDB
Do Not Trust Anybody: ZK Proofs for Image Transformations Tile by Tile on Your Laptop
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| Presentation: | Slides |
| Abstract: | The Internet has plenty of public images that are transformations (e.g., resize, crop, grayscale) of original unpublished ones. Various reasons recommend to keep private an original image, such as its economic value and its sensitive content. Several concrete scenarios, including selling images over the Internet, fighting misinformation and detecting deep fakes, would highly benefit from a system allowing to efficiently prove and verify the authenticity of a transformed image (i.e., the public image is a result of a faithful transformation over a private and authentic original image). This work presents the design of a system allowing the possessor of a signed private image to compute a faithful transformation, guaranteeing 1) confidentiality (no leak), 2) efficient proof generation (the proof can be computed with a cheap laptop), 3) integrity (only the advertised transformations have been applied) and 4) efficient fraud detection (fast detection of bogus proofs). Our system is based on a divide-et-impera approach through sub-transformations applied to tiles of the original image that are then reconnected together along with their sub-proofs. We discuss how to realize a few transformations. In particular, we have performed an experimental evaluation on the popular resize operation and the results confirm the viability of our approach. A faithful transformation of a high-resolution image of 30MP with a tile size of slightly less than 750KP can be generated on a common PC with 16GB of RAM and 8 cores, leaving free some resources for other light computations. The total amount of time to compute the proof for the entire image is slightly more than 45 minutes. Prior results require either an excessive amount of memory during the computation of a proof (resulting in huge proof generation time due to page faults) or the upload of the original image to some external cloud services negatively affecting confidentiality/decentralization. |
| Video: | https://www.youtube.com/watch?v=X8ebjijCTMA |
BibTeX
@misc{rwc-2024-35369,
title={Do Not Trust Anybody: ZK Proofs for Image Transformations Tile by Tile on Your Laptop},
note={Video at \url{https://www.youtube.com/watch?v=X8ebjijCTMA}},
howpublished={Talk given at RWC 2024},
author={Pierpaolo Della Monica and Ivan Visconti and Andrea Vitaletti and Marco Zecchini},
year=2024
}