They could tie or "back" respective CBDCs with e.g. some Bitcoin holdings. Easy to prove and︃ even way easier to audit by anyone who cares.
No guarantee in itself that such︄ a backing will be honored over time (history shows it will not) but at least︅ to kickstart something, it could be done.
No guarantee in itself that such︄ a backing will be honored over time (history shows it will not) but at least︅ to kickstart something, it could be done.