However now comes the crucial difference. Assume I have 2^256 participants, numbered 0, 1, 2, 3, ... How long will they need for the first block? In the current (parallelizable) PoW used in Bitcoin they need a few microseconds. Every participant uses his own number as nonce in the first round...and most likely one of them will produce a hash which is smaller than the current target value. In the non-parallelizable PoW I am thinking of, they will still need more or less 10 minutes as they should, since this corresponds more or less to the number of operations they have to do before they get a realistic chance for reaching the goal. However, since there is some variability, also a slower CPU with better random choices gets a chance.
I think I now understand what you're talking about. This is basically making the computation more granular, significantly increasing the time it takes to test one value (from a microsecond to 10 minutes).
I think you'll find that still, an entity with enough resources wins, and more easily than with the current system.
Thanx again for challenging my thoughts in the discussion. This is very fruitful.
You're welcome, glad to help.