Miden Bundles Private Stablecoin Finance Into a "PriFi" Stack as Researchers Bring Zcash Payment Proofs to Base

Miden, the zero-knowledge network that spun out of Polygon Labs, has announced what it calls the PriFi stack. Secondary coverage describes the stack as private stablecoins combined with privacy-preserving infrastructure for identity, banking, tokenized real-world assets and vaults. Its base is USDCx, a private stablecoin backed by USDC through Circle's xReserve. Users reach it through Bread, Miden's self-custodial wallet, which handles sending, receiving and swapping, with earning and cross-chain actions listed as coming. Bankless reports that Miden opened an invite-only partner mainnet on October 26 and that wallets came pre-funded with USDCx to cover fees. Because Miden keeps account state on users' devices, it needs a way to recover lost state. "Guardians" run by LambdaClass, Gateway, Para and KODA back it up.

Aztec, the privacy layer-2 (L2) network on Ethereum, released RollingChat, a message board that keeps the author private while applying automated moderation and an integrated artificial intelligence (AI) bot. The demo addresses a practical question for privacy chains: how to enforce content rules without learning who posted.

On Ethereum Research, the Seam proposal follows a different approach. In Seam, a contract on Base checks every Zcash block header against Zcash's consensus rules. It verifies the Equihash proof-of-work solution through the BLAKE2b precompile defined in Ethereum Improvement Proposal (EIP) 152, along with difficulty adjustment, time rules and cumulative work. The post includes the 25-second block time that Zcash's planned NU7 upgrade would introduce. Contracts on Base can then read Zcash state and accept proofs of shielded payments without a trusted bridge and without linking the payer's Zcash activity to their Base address.