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Practical Privacy Goes Live: Miden Partner Mainnet Opens

Miden partner mainnet is live, starting with our launch partners. You can jump in today using Bread, the private wallet powered by Miden, if you have an invitation.

Paying someone on blockchain can reveal more than the payment. It can expose the sending account’s balance and transaction history, giving customers, counterparties, and competitors a view into financial activity they would otherwise have no reason to see.

We believe financial privacy should be part of how blockchain works. People should be able to move funds without making their balance or full transaction history public. Businesses should be able to manage a treasury privately while retaining the approvals, recovery options, and asset controls their operations require.

Partner mainnet begins putting that approach into use with real assets. Invited users can access Miden through Bread, while launch partners bring infrastructure and apps onto the network.

What’s live, and who can participate

Partner mainnet is an invite-only phase for partners and invited Bread users. It gives participants access to live infrastructure while we test the network ahead of broader availability.

Before moving funds, understand the conditions of this phase:

  • Pre-registration and invitation code are required for Bread mainnet access. (Check Get Bread and Step Into Miden Partner Mainnet for more information)
  • The network is temporary. You will need to withdraw your funds before we reset for public mainnet.
  • Additional privacy safeguards apply during this phase. Encrypted transaction data is shared with network validators. Threshold encryption prevents a single validator, or Miden acting alone, from decrypting that activity.
  • Some actions expose information outside your private account. Swaps are public today. Bridges and outside providers receive information needed to process transactions.

The approach behind this launch

In Practical Privacy Is Key to Blockchain’s Next Era, Miden founder Bobbin Threadbare describes the philosophy guiding the network:

Instead, we aim to build a protocol that is conceptually closer to how physical cash operates: full privacy for the vast majority of users, and conditional privacy for a small subset of high-risk activities. We call this approach ‘practical privacy.’
— Bobbin Threadbare, Founder.

Partner mainnet is an early step toward that goal. This phase has specific privacy limitations, including encrypted transaction data shared with validators, as described below.

Your way in is Bread

Bread is your front door to Miden, a private, self-custodial wallet available on Chrome, iOS, and Android that keeps your balances and activity hidden by default. Consider it the best thing since sliced bread for your privacy.

Behind the scenes, Guardian backs up and synchronizes private account state so you can recover your account on a new device. Bread uses a three-key setup (everyday key, recovery key derived from your recovery phrase, and Guardian key) to maintain account access without relying on a single key. Note that spending limits on Bread are configurable directly within the wallet interface.

On partner mainnet, you can:

  • Hold, send, and receive supported assets on Miden.
  • Move supported assets between Miden and supported networks.
  • Swap supported assets where pairs and liquidity are available. 

Check the Support page for supported networks and tokens. For more on Bread’s security, recovery and privacy, read How Bread Works.

Enter your invitation code in Bread to get started. If you don’t have one, join Bread early access or try the public testnet without an invitation.

Privacy for financial work

A public ledger can reveal a business’s treasury balance, payment activity, and approval structure. Keeping that information private creates a coordination problem: teams and services still need ways to approve transactions, recover account data, and apply rules.

Miden addresses those needs through private multisig, Guardians, and issuer-defined asset controls.

Private multisig for teams

Miden’s private multisig is designed to keep account balances, signers, and signing rules out of public view. Teams can set spending limits that require additional signers for larger amounts.

The multisig supports ECDSA and Falcon signing schemes and is backed by Guardians. Falcon is designed to resist quantum attacks; the protection of a particular account also depends on its signing configuration.

Explore the multisig application at multisig.miden.xyz.

Guardians for account recovery and synchronization

When private account data stays offchain, protecting a private key is only part of account recovery. Users also need their latest account state: the data describing the account and its assets.

Guardians back up and synchronize that state, helping users continue using their accounts across devices and recover state after losing a device.

This role is separate from protecting the user’s private keys. A Guardian processes account-state updates to provide its service, so privacy from public observers does not imply that the Guardian has no access to account information.

Asset controls for issuers

Miden supports asset callbacks: issuer-defined code that runs when an asset moves into or out of an account.

Issuers can use callbacks to enforce freezes, holding rules, or transfer limits. These controls allow an issuer to apply rules to its asset without requiring the holder’s full account state to be published onchain.

This is what we mean by practical privacy: keeping financial information out of public view while giving applications and issuers ways to implement the controls their products require.

The partners and applications building on Miden

Partner mainnet brings together the infrastructure supporting the network and the teams developing financial applications on it.

Guardian infrastructure at launch

LambdaClass, Gateway, Para, and KODA run Guardians at launch, supporting backup and synchronization of private account state. This infrastructure helps users recover their account state and use private accounts across devices.

Applications building on Miden

Qash is building a B2B neobank focused on payroll and treasury management, while Sempo is developing borderless payments and digital dollar accounts. Both address financial workflows where businesses and individuals have reasons to keep their account activity private.

Darwin is working on tokenized stocks and structured investing, and port0.sh is building a token exchange.

Other teams are developing tools for using and managing Miden accounts. Forkchoice Innovations is building multisig, Miden Name is developing a name service, and Walnut is creating a playground for trying Miden.

Partners across the financial stack

The ecosystem also includes KODA in custody; Fuze and CBI in banking and markets; Libeara in real-world assets; Epoch Protocol in execution and intents; Billions in identity and verification; Predicate in compliance; and Circle in stablecoins – USDCx, issued by Miden via Circle xReserve, is used to pay network fees on Miden.

Protocol and infrastructure contributors

Nethermind, OpenZeppelin, Massa, Reilabs, Pragma, Epoch, and Para work with us on protocol and infrastructure development. OpenZeppelin has also audited Miden’s transaction kernel and core smart contract libraries.

How Miden handles private transactions

Miden moves transaction execution and proof generation to the user’s device. The device executes a transaction and generates a zero-knowledge proof that it followed the rules, which the network verifies before recording the update.

For private accounts and notes, the chain stores cryptographic commitments rather than publishing the underlying private state. Guardians provide backup and synchronization for account state.

During partner mainnet, encrypted transaction data is also shared with validators as an additional safeguard. This arrangement operates alongside proof verification and introduces a trust assumption: although a single validator cannot decrypt the data, threshold encryption depends on a group of validators.

Privacy also depends on the action you take. A transfer between private accounts, a public swap, and a bridge transaction expose different information to the services involved.

The work behind this launch

Miden began in 2020 with Distaff, Bobbin Threadbare’s research virtual machine for generating zero-knowledge proofs of program execution. That work continued through Winterfell at Meta and Polygon Miden, launched in 2021.

Our first testnet shipped in May 2024. In 2025, Miden became an independent company with a $25 million seed round led by a16z crypto, 1kx, and Hack VC.

Trail of Bits audited the Miden VM before launch, and OpenZeppelin audited the transaction kernel and the core smart contract libraries.

Partner mainnet builds on that research, development, and testing by bringing partners and invited users onto live infrastructure.

What comes next

During this phase, we’ll send more Bread invitations, add partners, and share what we learn from operating the network with real assets, including issues we find and how we address them.

Public mainnet follows this phase. Before that transition, participants will need to withdraw their funds ahead of the network reset.

To participate:

Regional restrictions apply. Check the relevant product’s availability and terms before participating.