5 ms·

> It feels like this isn't a large enough leap forward. The hash it relies on is broken, so their hand has been forced.

• throwaway2048 6y ago
  sha1 is not meaningfully broken for BitTorrent, It would require a second pre-image attack to meaningfully hurt it, you can not take an existing hash you don't control and synthesize a matching set of incorrect/malicious data. Second preimage attacks are MUCH harder to pull off, even md5 is still safe from them, many years after they were found to be broken in other contexts. The only thing that sha1's weakness would let you do in a bittorrent context is create a torrent, then let you send fake data for a chunk, which really does not seem very useful, because you could just make the data malicious when you created the torrent.
  • __s 6y ago
    The writing is on the wall, no need to wait for these attacks to actually exist before beginning migration
    • upofadown 6y ago
      Everyone thought that for MD5...
  • admax88q 6y ago
    It's not super easy, but you could create a legitimate torrent of some popular content, as well as a malicious version. Use the legit version to gain popularity and then distribute malicious chunks to select peers. Certainly not a trivial attack, but not benign either.