This section of the Beemocracy proposal for CIP-1694 shows how the Cardano blockchain itself can serve as reputation system for governance. This is accomplished by hard-linking a politician’s explanation of spending actions with the actual signatures for on-chain government spending.
The proposal linked above shows how a textual solicitation for a governance proposal is hard-linked to a DRep’s vote transaction. But the very same method could be used for any transaction including spending.
Basically we are making use of the fact that on the Interplanetary File System, the hash of a document is it’s URL. This makes it possible to securely link a document with a spending signature.
While Mithril for aggregation and zero knowledge proofs on Midnight are imagined for voter privacy, this could be accomplished on the L1 if you are going for transparency.
While privacy is desired for voting, transparency is desired for government actions. So in this case, the L1 is the best place to host the reputation system described by Beemocracy for CIP-1694.