Here is the report of the research internship that took place from Juny to July 2021 at INRIA Rennes under Emmanuelle Anceaume supervision, based on the generalization and application to the Bitcoin blockchain of the article Mining in Logarithmic Space.
It enables us to compress the 358 GB Bitcoin blockchain to 4.3 GB while ensuring strong security properties.
If you have a look to piX.svg due to 4 130 elements displayed (rectangles and texts showing the difficulty in logarithmic base 2) I recommend to use a rendering software like Firefox (because Inkscape and Gimp don't seem to support this vectorial representation).