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Re:Google Drive flags file only containing “1” for copyright... by avisser on Monday January 24, 2022 @05:41PM (#30065091)
I wonder if this is an incredible hash collision. hash("1") == hash(disney_movie.mp4)
Re:Google Drive flags file only containing “1” for copyright... by xigoi on Monday January 24, 2022 @06:14PM (#30065475)
Not the case, since it also happens with other numbers.
Re:Google Drive flags file only containing “1” for copyright... by rezonant on Monday January 24, 2022 @07:05PM (#30065992)
well as it turns out hash("0") == hash(pirates of the carribean) as well.

Not sure how Disney is finding these.

Re:Google Drive flags file only containing “1” for copyright... by dwaite on Monday January 24, 2022 @07:48PM (#30066378)
Trying to hash to specific values explains how some direct-to-video stuff was created. The motivation certainly wasn't quality.
Re:Google Drive flags file only containing “1” for copyright... by rezonant on Monday January 24, 2022 @09:17PM (#30067049)
Well they were certainly before their time. Nowadays a seeded random JPG goes for a mint on the blockchain
Re:Google Drive flags file only containing “1” for copyright... by p1mrx on Monday January 24, 2022 @06:02PM (#30065347)
Assuming is's a cryptographic hash function, that sort of collision just never happens.
Re:Google Drive flags file only containing “1” for copyright... by askvictor on Monday January 24, 2022 @07:05PM (#30065995)
Well, it has to happen at some point. Exceedingly unlikely, but never say never.
Re:Google Drive flags file only containing “1” for copyright... by p1mrx on Tuesday January 25, 2022 @11:53AM (#30074174)
When the number of hash values (at least 2^128) exceeds the number of atoms in the observable universe (10^80), it's never going to happen.

... unless the hash function is broken, in which case it's not cryptographic anymore. Note that the birthday paradox doesn't apply when one of the inputs is trivial.

Re:Google Drive flags file only containing “1” for copyright... by askvictor on Wednesday January 26, 2022 @12:13AM (#30082013)
Just because there are a lot of possible values doesn't matter. There are also a lot of possible pieces of data that could be fed into the hash function. In fact, an infinite number. Which is larger than 2^128. Unimaginably larger. Collisions will happen. Sure, intentional collisions might be next to impossible, but collisions will happen.

Consider a piece of data that is 128 bits long. There are 2^128 possible values. A 128 bit hash function will either yield a unique value for each possible data value (which will exhaust the entire range of unique hash values), or you'll have a collision. Now, lets add in pieces of data that are 129 bits (or any other length) as well - you'll have a collision immediately.

Re:Google Drive flags file only containing “1” for copyright... by p1mrx on Wednesday January 26, 2022 @12:10PM (#30088222)
2^128 is a big number, and we live in a universe with physical constraints. The mathematical probability is nonzero, but it's never going to happen.
Re:Google Drive flags file only containing “1” for copyright... by Sharlin on Monday January 24, 2022 @07:20PM (#30066126)
h(1) == h(some_real_data) does not have to happen at some point. Collisions are unavoidable, but the point of a cryptographically secure hash algorithm is to ensure that for all h(x) == h(some_real_data), there are no values of x that can be found by brute force, or by cleverness either for that matter.

Of course, it’s always possible that the particular hash function used could be hilariously broken…

Re:Google Drive flags file only containing “1” for copyright... by pertique on Wednesday January 26, 2022 @12:44PM (#30088812)
Perhaps I'm misunderstanding you, but doesn't the existence of collisions guarantee that h(1)== h(some_real_data) unless the hash function is hilariously broken?

Cryptographically secure hash functions state that it's unlikely to occur, but the fact that you can take data a greater size than the output will guarantee that you'll have collisions. If you have collisions and the hash function is generating output that is uniformly distributed across the possible output space, you will hit h(1)==h(some_real_data) at some point (edit: given that "some point" is a mathematical concept, not an actual point in time. Of course, there's no guarantee that we'll ever get collisions for hash functions with massive output spaces. But I'd argue that's a limit of computing, not of the math behind the functions themselves)

Re:Google Drive flags file only containing “1” for copyright... by account42 on Tuesday January 25, 2022 @04:38AM (#30070014)
What makes you think that this would use a cryptographic hash instead of a perceptual hash?
Re:Google Drive flags file only containing “1” for copyright... by hderms on Monday January 24, 2022 @09:40PM (#30067221)
Birthday paradox could play a role if there's enough content out there