There's more than one "government," that's what I mean by decentralization. There are thousands of courts throughout the country. I don't want some federal agency to be responsible for verifying the legitimacy of every warrant sent from every court.
What if the head of the agency responsible for verifying these courts institutes a policy that courts will lose their verification for rulings against abortion?
What if two courts in neighboring jurisdictions claim to be the same court? They each submit a different public key, but both can verify they hold the private key that pairs with the public key they submitted. How does the federal agency even verify the identity of a courthouse? Do they need to physically visit them and meet with the judge to tap a Yubikey?
What if somebody steals the YubiKey from the judge? What if a referendum dissolves a jurisdiction?
What is the process for revocation of verification?