Friday, February 15, 2019

Week 10 - Cryptography now being used in the fight against deepfake videos



Video is now ubiquitous in our daily lives. Law enforcement, in particular, relies on it for investigations in addition to footage from witnesses and other sources. Reliance on video has opened up an unforeseen threat, “deepfakes.” The integrity of video footage has now come into question as the proliferation of software allowing video manipulation increases. Fortunately there is a project on the horizon that takes aim in curbing “deepfakes” via cryptographic authentication.
            
Amber Authenticate, a tool developed to run silently in the background during video capture, can generate hashes at user defined intervals. Hashes are then recorded on a public blockchain which can be used to authenticate the same footage snippet through the algorithm at a later date. Dissimilar hashes tip the user off to the possibility of tampering.
Best practices should be used when setting hashing intervals of course. Too long of an interval could result in quick, undetectable tampering, while too short of an interval may be cause system constraints and can be overkill. Situations that would benefit from short intervals would law enforcement body camera footage while storefront CCTV camera recordings would best be suited for long intervals.

Shamir Allibhai, Amber CEO, expresses that systemic risk with police body cameras inherent to many manufacturers and models and the threat of deepfakes can make it almost impossible to detect a fake once entered as evidence. Currently, detection is always a step behind, which Amber Authenticate aims to bring in-step with efforts to manipulate video.
Human rights activists, free speech advocates, and law enforcement oversight committees see great potential in a tool like Amber Authenticate in exposing cover-ups of abuse. The governments can also benefit from a video integrity tool as well. Allibhai presented his video cryptography solution to Department of Defense and Department of Homeland Security representatives. Also in attendance were vendors like Factom who are also working on a similar video authentication tool.
Built on popular open-source blockchain platform Ethereum, Amber Authenticate includes a web-based Graphical User Interface. The interface provides feedback, in the form of a green frame, when the video is authentic, and a red frame when a mismatched hash has been identified. Amber Authenticate also displays an “audit trail” listing original file creation, uploaded, hashed, and submitted to the blockchain.

Amber Authenticate creator Shamir Allibhai is confident manufacturers will want to license his software for use in CCTV and body camera applications. This comes after his research consultant Josh Mitchell was able to find vulnerabilities in five different models of popular body cameras. Mitchell was able to prove compatibility of Amber Authenticate with some of those popular brands.
Video authentication tools for body cameras in particular is a long time coming for this platform. Civil liberty union policy analyst Jay Stanley says that Amber Authenticate will have to be evaluated against industry standards for tools of this caliber. Stanley is hopeful that other products like Amber become the available standard and perhaps provide confidence in evidence back to communities.

References


Newman, L. H. (2019, February 11). A New Tool Protect Videos From Deepfakes and Tampering. Retrieved from Wired.com: https://www.wired.com/story/amber-authenticate-video-validation-blockchain-tampering-deepfakes/

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