How is it that more complex keys are discovered but simpler one like 64 have not? i would have thought the ones after 64 would be significantly more difficult/nearly impossible. Is there any reason why this is the case?
Every five txs the public key is exposed. Maybe someone find it with other approach.
There is no "approach". The whole point of creating original transaction is to prove it, and it has been proven solid for 6 years since then.