IIRC BitTorrent still uses SHA-1, which is becoming more problematic.
BitTorrent v2 uses SHA-256, but in any case SHA-1 is still second-preimage resistant. And the BitTorrent piece hashes are included in the .torrent file, so you would need to find a double collision.
alt Hacker News
BitTorrent v2 uses SHA-256, but in any case SHA-1 is still second-preimage resistant. And the BitTorrent piece hashes are included in the .torrent file, so you would need to find a double collision.