> People already added it into bitcoin if you stretch the definition a bit.

Which is a fancy way of saying that they haven't. The only images in the bitcoin blockchain are ascii art.

There are plenty of hashes of different types of data in the bitcoin blockchain, but hashes are not the hash function's input data.

Schneier himself repeated this bogus "there's illegal content in the bitcoin blockchain already!" claim, which shows the legs this false meme has on it.

Please stop repeating this falsehood.

I agree that a hash of data != the source data, but these links seem to indicate that it is at least possible, if not already evident, that illegal images and content can be encoded into the bitcoin blockchain (and presumably other blockchains that permit similar writing to the ledger)

JPG of Nelson Mandela encoded into bitcoin blockchain: http://www.righto.com/2014/02/ascii-bernanke-wikileaks-photo...

Illegal porn and classified documents embedded in the blockchain (page 3): https://www.accenture.com/_acnmedia/pdf-33/accenture-editing...

Original research source: https://fc18.ifca.ai/preproceedings/6.pdf

The data may may have been encrypted with a key that only some people know, and to others it's just random noise.

By that definition, however, every file could be transformed into an illegal one through a suitable cipher and key.

Then there's the concept of steganography.

Digital data is interesting for sure.

Really? That’s very sad, but I’m not too surprised.

(Unless you’re saying that the bits 0 and 1 already exist in the blockchain, which is reaaaaallllyyy stretching the definition.)

There’s the concept of “illegal numbers”, which means that there are technically numeric representations of images or copyrighted material that you can’t know/possess without breaking a law. But the law is subjective which is why we have judges and juries to apply judgement to whether having a large number written on a piece of paper is equivalent to possessing illegal material.