Fyi this is called a merkle tree. Also the data structure that blockchain uses and a couple other protocols. They’re wonderful and surprisingly easy to implement.
Most ideas in CS are old as dirt. There was a flurry of theory advancements mid-century and a lot of work since then has been putting those ideas into practice.
Even back in renaissance days with the most advanced mathematics there were unknown prior art
I have a theory this is a consequence of Euclid not being taught anymore.
..so right about the time computers were invented, people figured out how to use them and did some basic research.