I have an idea about it via multi-tier AI-generated templatized math problems with AI-generated solution verifier functions. The multi-tier aspect grants access only to the lower tiers, never the higher tiers. Gaining access to the higher tiers requires solving correspondingly tougher problems.
Good cryptosystem design with ubiquitous PKI support oughta do the trick.
("Make a problem that is ridiculously expensive unless you have a hint... in which case, it's a total breeze" is a foundational task in crypto)
provide a millennium prize solution to proceed
this will work for a year at most. Let's go big: provide largest prime number to proceed.
you can benchmark the uploaded weights? Only the worthy can exfiltrate
If your benchmark score beats the current incumbent, you get to wipe and replace them. There can only be one!