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Content hash based distribution has downsides too: E.g. updating content can result in people still stuck on old versions because the links weren't updated. C
by nullc 5y ago
Content hash based distribution has downsides too: E.g. updating content can result in people still stuck on old versions because the links weren't updated.
Content hash distribution can also easily have privacy problems. Say there is a site for rubber band fetishists that you don't want people to know you've visited. I can interrogate if you've visited this site by embedding some of its content-- if you load it instantly because you have it cached, then I can be fairly confident that you've visited that site before.
- api 5y agoThe first point is no different from regular dead links or outdated URLs. The second can be mitigated but is a legitimate issue.
- samatman 5y agoUnfortunately, stale hashes are a worse problem in content-centric networks than dead links. So Alice links to some content in Bob's site, but Bob made an embarrassing error and wants to update it. Very well, and Alice has to update the hash pointing to Bob's content: but now any hash pointing to Alice's content is stale, and so on, ad infinitum. There are ways to solve this problem, but none of them force a linear forward history. Basically, you can request all Merkle chains featuring a base hash, and verify that Bob signed all of the branches, but only discipline can keep this collection in a linear order. This is probably fine in practice, just follow the longest branch. And now you have Secure Scuttlebutt!
- remram 5y agoThis last attack is possible regardless of whether content is addressed by hash or not, it only needs caching.