Continuing a trend of new posts that make me dredge up pieces from my archives, I recently read about the OFF System, a new theoretical P2P network that purports to get around copyright issues with a brightnet.

Why don’t I just let the guys at Ars Technica explain it?

The ideas behind the OFF System were originally expressed in a more formal paper (PDF) that outlined how copyright does not extend to random numbers. Thus, to get around copyright restrictions, the OFF System cuts up files into tiny chunks (128 kilobytes each) and then encrypts these chunks by using an XOR (exclusive OR) boolean operation with two sets of random numbers. The encoding system is similar to a One-Time Pad cipher, and makes decrypting the contents by someone who does not have the appropriate key extremely difficult. The use of two sets of random numbers instead of just one is a kind of cryptographic sleight-of-hand which is used to argue that the bits are no longer copyrighted.

The argument goes something like this: a copyrighted file is converted into small chunks, which are labeled “A.” These chunks are still copyrighted by the original owner. It is then encrypted by performing an XOR operation with a block of random numbers, called “B.” The resulting block “C,” is still copyrighted by the original owner, but things get really interesting when C is encrypted again, this time using not a series of random numbers, but a block “E” that is pulled out of the user’s cache. Block E is itself the result of an encryption of someone else’s copyrighted file (D), which would make the final result (F) copyrighted by two content owners at the same time. As it is not possible for both parties to hold a copyright on the same content, the result is that neither party does, and thus the block can be transmitted without fear of lawsuits from the RIAA or MPAA.

This sounds awfully familiar to me. In fact, it’s more or less the exact same concept as Monolith, which I blogged about just this past March. Essentially, both authors/developers claim that enough encryption and/or tying files to other files make these arbitrary digital representations indistinguishable from one another and therefore uncopyrightable.

As Ars says, though, it’s an interesting proof-of-concept (it really is: read the linked PDF file, and possibly the developer’s explanation and if you haven’t read my write-up of Monolith, read that too), but when it comes down to it as a legal defense, I’m not sure any judge is going to be tech-savvy to rule in favor of the filesharer.

Just a thought: maybe XOR isn’t the cure-all for filesharing woes.

On a semi-related note, a truly useful little tool for filesharers is a darknet (basically, a method of surfing completely anonymously), and the infamous Piratpartiet (the “Pirate Party,” a Swedish political party formed around the venerable PirateBay bittorrent site) has formed a super-fast darknet that users can buy into for 5 Euro a month.

§1303 · August 15, 2006 · Tags: , , ·

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