First off, that has not been proven about pi, but it is heavily theorized. Second, you need the substring index, which, for a large file is guaranteed to exceed the original's file size to begin with. Transmitting that substring index is likely equivalent to compressing the file.

Courts aren't robots and people are judged by other people. Nobody will go to jail for holding a file with all possible files in it. But using that file with a specific substring index to extract something illicit, with intent, will almost certainly not make the courts happy. IANAL.

>But using that file with a specific substring index to extract something illicit, [...] //

The question at hand though, is if you don't extract the illicit thing [from the Blockchain] is possession of the Blockchain enough.

FWIW I think possession has to be the measure used for child pornography and similar content, at present. But what is meant precisely by possession may need some interpretation (does one "possess" a file if one has the magnet link?) and may evolve in the future if such Blockchain attacks become of interest to the legislature.

>you would need something else other than just possession of a number to make that possession illegal.

Yes, the index, which would itself be the encoding of the file. It's just Huffman coding optimising for the ratio between a circle's circumference and its diameter.

It provides no pushback at all when a picture has been taken, jpeg encoded and then sliced into pieces and inserted onto the blockchain as extra data on a number of transactions, in a way easily recognised and easily re-extracts.

Sure, those numbers could have come about some other way, but they didn't.

Your hypothetical decoder is actually going to contain a very large amount of very specific data as well, so much so that the 'circle' part of it is more or less irrelevant. You've just defined a (very poor) data encoding scheme.

If that is the case, then the information will be contained in the "decoder", not in pi itself. So that particular "decoder" should be banned, not pi. Other "decoders" that point to other parts of pi would not be banned.

So, if you don't have the decoder ...?

How about if you have it but never used it, so you have the index but never expanded Pi that far, or doing the expansion would take longer than the age of the Universe, say?

So, how about if you never viewed the 'file' from the Blockchain, aren't we creeping gradually towards saying that would be fine too. Of course the law has elements necessary for practical enforcement too which we generally ignore when waxing philosophical.

Information theory, which the law uses informally and approximately correctly, provides a solution.

Yeah really it is pointing out that the law is stupidly written conceptually as pi technically contains all of the child pornography in the world once you go out enough digits. In the real world it requires a judge to put a stop to utterly stupid abuses like arresting someone for having enough sources of noise on them which through a series of operations could be transformed into child pornography while not dismissing a 1s complimented video file of the defendant presenting their driver's license to a camera before molesting a child as tampered evidence.

Personally I believe the law is long overdue for refactoring but that it would be a twofold nightmare to first actually do it and second getting it approved through the mechanisms of legislation.