Consider using a random value for cross-seeding rather than a hash of the announce URL

[ghost]

Using the hash of the announce URL as entropy for cross-seeding can lead to a potential privacy violation. Consider an anonymous uploader on a private tracker. If they use torrenttools's cross-seed feature, it becomes possible to tell if two anonymous uploads came from the same person, unless the uploader regularly rotates their passkey (which is usually a painful process). Please consider just using a random value for this like pyrocore does.