3 ms·

That is seriously the hash function they used? I assumed a competent hash function, hell, any common hash function is better even if they fail at resize/compres

• nullc 5y ago
  Apple 'neuralhash' usually survives resize (the first step it does is resize the image to 360x360) or minor compression lossy changes. But the price of that is that it's not secure against generating arbitrary preimages based on fairly arbitrarily targets, with results that look nothing like the original image you're matching (if one even exists). They could do some downsample, transform, quantize, sha256 approach that would still survive some tiny amount of differences. ... but apple favors easily constructed false positives over false negatives, even though its trivial for anyone trying to avoid their function to get a false negative. Their scheme only protects against accidental false negatives. It's just a symptom of systematically favoring factors other than the privacy and security of the actual owner and user of the computer.
  • raxxorrax 5y ago
    Wow, that is seriously a naive approach. Honestly, I would have expected much more here. That makes the libraries of hashes for content almost useless. Hope they extracted features that could be used in a more sophisticated approach.