I came across tweet of Daniel Roberts about, 1996 paper titled:
HOW TO MAKE A MINT: THE CRYPTOGRAPHY OF ANONYMOUS ELECTRONIC CASH
Sources include "Tatsuaki Okamoto" π³ Who else would be able to sit anonymously on 1 million coins? Oh, and they invented SHA-256...? tweet: https://twitter.com/danroberts0101/status/1702440110002729356
It would be big if true.
Here's the link: https://groups.csail.mit.edu/mac/classes/6.805/articles/money/nsamint/nsamint.htm