Invited users can now move real funds on the Polygon spin-off's privacy chain, though validators can still see private inputs for now.
Miden, the a16z-backed privacy chain that spun out of Polygon last year, opened its partner mainnet on Monday (Oct. 26th). Launch partners and invited users can now transact on it with real funds for the first time.
This is a limited, temporary phase meant to stress-test the network. Co-founder Bobbin Threadbare says the public mainnet is a few months out.
What’s the Scoop?
How it works: On Miden, your own device runs each transaction and proves it with STARKs, a type of zero-knowledge proof that relies only on hash functions. The chain stores just commitments (hashes) of private account data. Threadbare says most transactions can be proven in under three seconds on a phone. Guardians run by LambdaClass, Gateway, Para, and KODA back up private account state so users can recover it.
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How to get in: Access runs through Bread, Miden’s self-custodial wallet for iOS, Android, and Chrome. Early-access codes go out in waves starting today. Wallets come pre-funded with USDCx, which Miden issues through Circle’s xReserve, to cover fees. Balances are capped below $1,232.462, a nod to the “Goldilocks” prime Miden uses under the hood. From there you can send, swap, bridge through routes like Agglayer and NEAR Intents, and deposit into Aave on Ethereum. Miden’s advice is to only use funds you can afford to lose.
The guardrails: Privacy isn’t absolute yet. In his launch article, Threadbare explained that validators currently collect users’ private transaction inputs to double-check proofs, so activity is hidden from the public but not from validators. Validators also store threshold-encrypted transaction details that a group of them could decrypt “during extraordinary events (e.g., hacks).” Swaps are public for now, too. Miden says it’s prioritizing safety for this phase. It plans to drop the guardrails once the protocol is battle-tested and formally verified, a step Threadbare places after public mainnet.
What’s next: Partner mainnet is temporary, and users will have to withdraw before a reset whose deadline hasn’t been announced. Public mainnet will migrate from the Poseidon2 hash function to a Blake3-based one, since confidence in Poseidon2 has been shaken. It will also bring a more robust fee model and full ZK block proofs. Today’s network still runs on flat fees, partial block proofs, and a centralized block producer.
William M. Peaster
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William M. Peaster, Senior Writer, has been with Bankless since January 2021. Immersed in Ethereum since 2017, he covers the onchain frontier with a particular interest in art, games, and other culture apps. He has a background in creative writing and writes fiction in his free time.