drew from dropbox here. i hope you guys can give us the benefit of the doubt: when something pops up that encourages people to turn dropbox into the next rapidshare or equivalent (the title on HN was suggesting it could be the successor to torrents), you can imagine how that could ruin the service for everyone -- illegal file sharing has never been permitted and we take great pains to keep it off of dropbox. the inte…
we've fixed the deduplication behavior serverside to prevent "injection" of files you don't actually have, for a variety of reasons I think this was a good call, and not just for the piracy issues but for the substantial information disclosure and possible misappropriation of sensitive documents that it could have facilitated. This is something that's been on my radar for some months, and frankly seemed like a signif…
They match duplicate files with an SHA256 sum and size in bytes. With those two factors, the probability of a collision is incredibly tiny and impossible to exploit usefully. If you tried a trillion combinations you might find a useless file, but by then you would be detected and banned from Dropbox.