5 ms·

This seems pretty easily defeatable: an adversary just needs to track the timestamps of various blocks, and the last one that gets created is the "real" one. Th

This seems pretty easily defeatable: an adversary just needs to track the timestamps of various blocks, and the last one that gets created is the "real" one. The stuff about copyright seems pretty dumb, obviously the most recent block is the interesting one, that you've just "encrypted" with the previous blocks. Also, even without doing any tracking, you can narrow down the uploader to a set of at most N people, where N is the number of blocks (which presumably can't be too big for performance reasons).

ComputerGuru 6y ago
The copyright stuff is bunk, but their defense isn’t (just) what you’ve said but rather that a single block is used to decrypt multiple files so their defense is that no one copyright owner owns the block in question. Which of course is BS since any part of a component derived from illegally sourced copyrighted materials renders the entire derived work in violation (eg a mixtape with one improperly sourced song or twenty is just as “fair game” for a lawsuit).
- musingsole 6y ago
  As mentioned elsewhere, it is difficult to prove where any block in OFF was derived. So while a block is used to rebuild a copyrighted work, the block itself can't be subject to copyright, or more so, could have been generated by a freely available work and so has no ties to the copyrighted work. It seems like building a dictionary and then a system to rebuild books by combining fragments (words) from the dictionary. The book can be copyrighted, but the words couldn't be. Even if the word was coined in the book and submitted to the dictionary.
contravariant 6y ago
The problem with that tactic is that all blocks are essentially random noise (in isolation). You could strengthen this a bit by always writing 2 blocks, one of which is random noise, and the other a xor of that block and t-2 others. This way each block is provably completely random (the blocks just aren't independent from one another).
- dooglius 6y ago
  If you write 2 (or N) blocks, the new blocks still comes from you as there's a data dependency on the external blocks you use, so the most-recent tactic still de-anonymizes the uploader.
dane-pgp 6y ago
> an adversary just needs to track the timestamps of various blocks Does an adversary necessarily have knowledge of every time a block is added to the system? > you can narrow down the uploader to a set of at most N people, where N is the number of blocks I would expect N to be greater than 1000, and I don't think a 1 in 1000 chance of someone being the uploader is reasonable suspicion.

ComputerGuru 6y ago

The copyright stuff is bunk, but their defense isn’t (just) what you’ve said but rather that a single block is used to decrypt multiple files so their defense is that no one copyright owner owns the block in question. Which of course is BS since any part of a component derived from illegally sourced copyrighted materials renders the entire derived work in violation (eg a mixtape with one improperly sourced song or twenty is just as “fair game” for a lawsuit).

musingsole 6y ago
As mentioned elsewhere, it is difficult to prove where any block in OFF was derived. So while a block is used to rebuild a copyrighted work, the block itself can't be subject to copyright, or more so, could have been generated by a freely available work and so has no ties to the copyrighted work. It seems like building a dictionary and then a system to rebuild books by combining fragments (words) from the dictionary. The book can be copyrighted, but the words couldn't be. Even if the word was coined in the book and submitted to the dictionary.

contravariant 6y ago

The problem with that tactic is that all blocks are essentially random noise (in isolation). You could strengthen this a bit by always writing 2 blocks, one of which is random noise, and the other a xor of that block and t-2 others. This way each block is provably completely random (the blocks just aren't independent from one another).

dooglius 6y ago
If you write 2 (or N) blocks, the new blocks still comes from you as there's a data dependency on the external blocks you use, so the most-recent tactic still de-anonymizes the uploader.

dane-pgp 6y ago

> an adversary just needs to track the timestamps of various blocks Does an adversary necessarily have knowledge of every time a block is added to the system? > you can narrow down the uploader to a set of at most N people, where N is the number of blocks I would expect N to be greater than 1000, and I don't think a 1 in 1000 chance of someone being the uploader is reasonable suspicion.