I got the idea that a SHA256 hash could be rendered into something
difficult to forget. The rendering would involve using each of the 256
bits to specify something important about the rendering - important in an
instinctive human-memory way.
Let's assume such a rendering is possible, and that at any time, any person
can execute the rendering against the SHA256 hash of a consistent
representation of the UTXO Set. Sometimes, someone will execute the
rendering and discover that it is remarkable in some way (making it even
more memorable), and therefore will publish it.
The published, memorable rendering now becomes a kind of protection against
any possible re-writing of the blockchain from any point prior to that UTXO
Set. When everyone involved in Bitcoin recognizes this protection, it
relieves us of the need to retain the full blockchain in order to validate
the UTXO Set at that point, because enough people will recognize it, and it
can be validated without reference to any kind of prior computer record.
This does leave open the possibility that an attacker could create a more
favorable UTXO Set that happens to have a rendering similar enough to fool
people, or one that has exactly the same SHA256-hash, but that possibility
is remote enough to ignore (just as we all ignore the possibility that
whatever creates the master seed for our HD wallet will create a unique
I've been working on how such a rendering could happen. It could describe
music, characters, colors, plot points, memorable elements of characters,
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