A grounded technical look at the devnet-proven, code-reviewed Halo2 circuit behind Post Fiat’s shielded NAVCoin swaps: every major constraint, the measured CPU prover bottleneck, the K=15/key-cache optimization sprint, and the remaining path to GPU-accelerated proving.
A design for using Post Fiat to support private primary NAV subscriptions that add source-labeled USDC to NAVCoin reserves without walking a thin AMM book, plus private secondary OTC swaps for existing holders. The core claim is that TVL formation improves when issuance, reserve receipts, NAV policy, and shielded settlement are co-located; the hard boundaries are USDC provenance, mint escrow enforcement, credential governance, replayability, privacy budgets, and secondary liquidity.