# Aztec vs Zama

> Zama lets Solidity contracts compute on encrypted values, with decryption held by a threshold of selected key-management operators. Aztec uses client-side private execution without a shared network decryption key.

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

## Side by side

| | Zama | Aztec |
| --- | --- | --- |
| Is the network unstoppable? | **Operators can pause it.** The litepaper describes 18 initial operators, 13 key-management nodes and five coprocessors, selected by reputation, alongside the host chain. Any one of them can pause the protocol in an emergency. | **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? | **Threshold decryption.** Values are encrypted under a network key. A two-thirds threshold of the key-management operators can decrypt, which is what contract-level access rules rely on. | **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? | **Encrypted types in Solidity.** Solidity contracts compute on encrypted values and define who may decrypt them, with off-chain coprocessors doing the work. | **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.** Builders can deploy confidential Solidity apps on a supported chain, free and without permission. Users can hold, send, and decrypt the values an app grants them. Running a key-management node or coprocessor is limited to selected operators. | **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 | Contract-defined access control. An application lists who may decrypt each value, and the key-management service decrypts only for them. Any operator can also blacklist sanctioned addresses. | 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 Zama does well

Programmable confidentiality in Solidity on supported public chains, with application-defined access to encrypted values.

**The difference.** Both let applications define disclosure. Compare the underlying trust assumptions: threshold key management for Zama, client-side private execution for Aztec.

## Sources

- [Zama Protocol litepaper](https://docs.zama.org/protocol/zama-protocol-litepaper)
- [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/zama. Published by Aztec Foundation.