Data shows that the EU's CSAM scanning will not have the intended effect

Re:Data shows that the EU's CSAM scanning will not have the ... by readams on Tuesday May 24, 2022 @11:51AM (#31493659)

That would be interesting since that would be likely the shortest known MD5 collisions. The shortest ones known are 512 bits differing by 2 bits.

If I had to guess, you might have been hitting collisions in a truncated MD5 hash. It's not uncommon to do something like take only the first 64 bits of the hash. Doing this you are quite vulnerable to birthday problem issues.

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Re:Data shows that the EU's CSAM scanning will not have the ... by withinboredom on Tuesday May 24, 2022 @12:07PM (#31493867)

It was in php using the built-in md5 function. I’m actually reaching out to a friend that still has the code to see what the exact string is that got hashed.

I have no idea if the database is still somewhere, if so, we can look at the git commit and figure out what the possible UPCs are and narrow it down to a couple of hours worth of time stamps. I have a feeling it would probably be more than 512 bits though. UPCs are can be longish, plus a time stamp with each digit being a byte…

I highly doubt the database exists in any meaningful way though, since the product was shut down years ago.

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