# Aztec vs Miden

> Miden opened an invite-only partner mainnet in October 2026: Miden operates the validators, which hold threshold keys to encrypted transaction data, and Guardian co-signers see the state of the accounts they back. Aztec runs a permissionless network where no operator or co-signer can read a private transaction.

Canonical: https://aztec.network/compare/miden  
Type: Comparison  
Reviewed: 3 November 2026  
Publisher: Aztec Foundation

## Side by side

| | Miden | Aztec |
| --- | --- | --- |
| Is the network unstoppable? | **Invite-only, Miden-run.** The partner mainnet is invite-only. Miden operates the validator set, and the documented operator roles cover sequencing, proving, data availability, and L1 submission. | **No one can stop it.** Permissionless sequencers and provers run the network. Upgrades follow public governance rules with a timelock. L2BEAT assesses the rollup at Stage 2. |
| Is there a privacy backdoor? | **Validators hold the keys.** Encrypted transaction data is shared with the validators, and a threshold of them can decrypt it. The Guardian behind a Bread account can see that account's state. | **No backdoor.** Private functions execute on the user's device and the network verifies a proof. There is no network-wide decryption key, no validator that re-executes private inputs, and no co-signer. Public calls and their inputs are visible by design. |
| Do they have private smart contracts? | **Private accounts and notes.** Smart contracts in Rust with private accounts and notes, executed and proven on the user's device. A private note puts only its hash onchain and its contents stay off-chain; encrypted notes, which would put the contents onchain encrypted for the recipient, are listed as a planned feature. | **Private + public contracts.** Noir contracts combine private state and functions with public ones, and anyone can deploy them. Contracts compose on Aztec and reach Ethereum through L1/L2 messaging. |
| Who can build and participate? | **Permissionless to use.** The partner mainnet is open to partners and to Bread users with an invitation code, under regional restrictions. Operating a validator is not open. | **Permissionless to use, build, and operate.** Anyone can deploy contracts or participate as a sequencer or prover under the published protocol, staking, and hardware requirements. |
| Compliance approach | Compliance runs through Miden's operators. The Guardian, the "entry point to Miden", exists to "manage state, co-sign transactions, and enforce compliance": every send, receive, and swap from a Bread account takes its signature, its operator can see the account's state, it denies transfers to OFAC-sanctioned addresses, and it may charge a "review fee" on transactions over $10,000. Miden launched private between users "but not against the operators", and its essay on practical privacy proposes conditions on large transfers: delays, proof of funds, or viewing keys a subset of validators could use to decrypt them. A user can instead choose an account that shares nothing with an operator, and has no recovery. | Selective disclosure at the application and user level. An application decides which facts it proves or publishes, and a user can share their own viewing keys with whoever they choose. No protocol-wide audit key, screening gate, or operator sits in the path of a transaction. |

## What Miden does well

Client-side proofs, Rust tooling, and a polished wallet: Bread with passkeys, spending limits, Guardian recovery, and private multisig with mixed Falcon and ECDSA keys. Private accounts and notes put only a commitment onchain and their users keep the contents off-chain, so a future break of encryption exposes nothing from the chain itself.

**The difference.** Both designs prove privately on the user's device. The difference is who else is in the path: on Miden, encrypted transaction data goes to a validator group that can decrypt it together, a Guardian sees the state of every account it backs, and Miden runs the validators. On Aztec, no one sees that data, and no one can stop the network: permissionless sequencers and provers run it.

## Sources

- [Miden: Practical privacy goes live, partner mainnet opens](https://www.miden.xyz/blog/practical-privacy-goes-live-miden-partner-mainnet-opens)
- [Miden: Guardian](https://www.miden.xyz/guardian)
- [Miden: How Bread works](https://www.miden.xyz/blog/how-bread-works)
- [Miden: Testnet v0.16, last stop before mainnet](https://www.miden.xyz/blog/testnet-v0-16)
- [Miden documentation: FAQ](https://docs.miden.xyz/builder/faq/)
- [Miden documentation: Notes](https://docs.miden.xyz/reference/protocol/note/)
- [Miden: Privacy simply scales better](https://miden.xyz/resource/blog/privacy)
- [Miden: Practical privacy is key to blockchain's next era](https://www.miden.xyz/blog/practical-privacy)
- [Aztec: private and public state](https://docs.aztec.network/developers/docs/foundational-topics/state_management)
- [Aztec: privacy considerations](https://docs.aztec.network/developers/docs/resources/considerations/privacy_considerations)
- [Aztec: governance voting](https://docs.aztec.network/participate/token/voting)
- [L2BEAT: Aztec Network](https://l2beat.com/scaling/projects/aztecnetwork)

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Markdown representation of https://aztec.network/compare/miden. Published by Aztec Foundation.