3 ms·
It sounds stupid... Storing the hashes? How many permutations of that photo will be protected? Surely the attacker can tweak the brightness or crop the edges.
by jondubois 9y ago
It sounds stupid... Storing the hashes? How many permutations of that photo will be protected? Surely the attacker can tweak the brightness or crop the edges.
- eridius 9y agoI would assume they're using the same sort of techniques that image search (e.g. TinEye) use, rather than literally just taking the SHA1 of the image file.
- qilo 9y agoMicrosoft has somewhat similar technology called PhotoDNA. How does PhotoDNA work? PhotoDNA technology converts images into a common black-and-white format and uniform size, then divides the image into squares and assigns a numerical value that represents the unique shading found within each square. Together, those numerical values represent the "PhotoDNA signature" or "hash" of an image, which can then be compared against signatures of other images. While the technology cannot be used to identify a person or object in an image, nor can it be used to recreate an image, it can be used to find copies of a given image with incredible accuracy and at scale across the 1.8 billion images shared online every day, even when the images themselves have been altered. https://www.microsoft.com/en-us/PhotoDNA/FAQ?3158ae95-fce7-480c-98aa-d3e75c620697=True https://www.microsoft.com/en-us/PhotoDNA/FAQ?3158ae95-fce7-4...