> For the complete documentation index, see [llms.txt](https://docs.citrea.xyz/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.citrea.xyz/advanced/clementine-signers.md).

# Clementine Signers

[Clementine](/essentials/clementine-trust-minimized-bitcoin-bridge.md), Citrea's trust-minimized Bitcoin bridge, relies on a set of **Signers** (also called **Verifiers**) to secure the bridge. These entities pre-sign the allowed spend rules, emulating covenant-like restrictions on Bitcoin. As long as one signer remains honest, funds can only move along Clementine's approved paths.

{% hint style="info" %}
In Clementine, the terms "Signer" and "Verifier" are often used interchangeably. These entities participate in the MuSig2 signing protocol to secure deposits and enable withdrawals.
{% endhint %}

## Role of Signers

Signers are a committee of N participants that:

* **Pre-sign allowed spend rules** - Funds can only move along Clementine's approved paths if at least one signer is honest
* **Participate in MuSig2 aggregation** - Sign `MoveToVault` transactions that move deposits into the bridge vault
* **Enable optimistic payouts** - When all signers are online, they can directly sign withdrawals without operator involvement
* **Monitor the bridge** - Signers also function as [watchtowers and challengers](/essentials/clementine-trust-minimized-bitcoin-bridge.md#roles-and-responsibilities)

{% hint style="success" %}
The bridge uses an N-of-N signing scheme for deposits, functioning as a key deletion covenant. This means the bridge remains secure as long as **at least one** signer's key is secure.
{% endhint %}

## Mainnet Signers

The following entities operate as Clementine signers on Citrea mainnet:

### Chainway Labs

Chainway Labs is the core development team behind Citrea and operates as both a verifier and operator.

| Property   | Value                                                                |
| ---------- | -------------------------------------------------------------------- |
| Website    | [citrea.xyz](https://citrea.xyz)                                     |
| Public Key | `024ebf6626277c974726217b20bae9fc088e7f66a530b5ea21d0d1650513a99fb0` |

***

### Galaxy

Galaxy Digital is a leading digital asset and blockchain company providing institutional-grade financial services.

Galaxy operates as both a verifier and operator.

| Property   | Value                                                                |
| ---------- | -------------------------------------------------------------------- |
| Website    | [galaxy.com](https://www.galaxy.com)                                 |
| Public Key | `02b0895dc582479793abb442d77e0f71bc040a7400eedb52ad4d1ce1e200be0560` |

***

### Coinsummer

Coinsummer provides blockchain infrastructure and validation services.

| Property   | Value                                                                |
| ---------- | -------------------------------------------------------------------- |
| Website    | [coinsummer.io](https://coinsummer.io)                               |
| Public Key | `0338c5e8932ed6b084f163a6d7a2b9a0af95f57d07c4c69567c0544e7fbfd93b98` |

***

### Omakase

Omakase is a professional node operator providing infrastructure services for blockchain networks.

| Property   | Value                                                                |
| ---------- | -------------------------------------------------------------------- |
| Website    | [0xmakase.co.jp](https://0xmakase.co.jp)                             |
| Public Key | `034c027c18a980c76b55a99d015cb0c845eb8875f2a403ff957b7e266d0aa66e1d` |

***

### Nansen

Nansen is a blockchain analytics platform that also provides staking and infrastructure services.

| Property   | Value                                                                |
| ---------- | -------------------------------------------------------------------- |
| Website    | [nansen.ai](https://www.nansen.ai)                                   |
| Public Key | `02c585eb3acfff97b5d1caf73368cb9e0139fd6c42ebe4b13c68d24e9e77d9d7c7` |

***

### Nethermind

Nethermind is a blockchain research and software engineering company known for building Ethereum clients and infrastructure.

| Property   | Value                                                                |
| ---------- | -------------------------------------------------------------------- |
| Website    | [nethermind.io](https://www.nethermind.io)                           |
| Public Key | `02582cb654c6ccc6fb4cd11a6c88af83a961b918385e9f30411ca94b5395e75048` |

***

### Laminated Labs

Laminated Labs provides professional validator and infrastructure services for blockchain networks.

| Property   | Value                                                                |
| ---------- | -------------------------------------------------------------------- |
| Website    | [laminatedlabs.net](https://laminatedlabs.net)                       |
| Public Key | `0310cc0687c18427ade30226629c30b1de5c6e714b261c4909172a6e4797f5bd51` |

***

### Hashkey Cloud

Hashkey Cloud is the infrastructure arm of HashKey Group, providing institutional-grade staking and validation services.

| Property   | Value                                                                |
| ---------- | -------------------------------------------------------------------- |
| Website    | [hashkey.cloud](https://www.hashkey.cloud)                           |
| Public Key | `025668e399d27f0b799ed8e87c3cdb2c142c12afe97d252bcb338be6146378f526` |

***

### Finoa

Finoa is a regulated digital asset custodian providing secure storage and staking services for institutional clients.

| Property   | Value                                                                |
| ---------- | -------------------------------------------------------------------- |
| Website    | [finoa.io](https://www.finoa.io)                                     |
| Public Key | `03e4674d0c2091c7f408c93ea5e5d94ee231c563cecc714c24da9cd37b24b22104` |

***

### Luxor

Luxor is a Bitcoin mining company and hashrate provider that also operates validation infrastructure.

| Property   | Value                                                                |
| ---------- | -------------------------------------------------------------------- |
| Website    | [luxor.tech](https://luxor.tech)                                     |
| Public Key | `03296b46f3f622d4d7f004c7c5b10f77fe3e6384358f87606ebe41b14919f7211b` |

***

## Aggregated Public Key

All signer public keys are aggregated using MuSig2 to form a single N-of-N aggregated key that controls the bridge vault.

Mainnet signer set public keys:

```
024ebf6626277c974726217b20bae9fc088e7f66a530b5ea21d0d1650513a99fb0
02b0895dc582479793abb442d77e0f71bc040a7400eedb52ad4d1ce1e200be0560
0338c5e8932ed6b084f163a6d7a2b9a0af95f57d07c4c69567c0544e7fbfd93b98
034c027c18a980c76b55a99d015cb0c845eb8875f2a403ff957b7e266d0aa66e1d
02c585eb3acfff97b5d1caf73368cb9e0139fd6c42ebe4b13c68d24e9e77d9d7c7
02582cb654c6ccc6fb4cd11a6c88af83a961b918385e9f30411ca94b5395e75048
0310cc0687c18427ade30226629c30b1de5c6e714b261c4909172a6e4797f5bd51
025668e399d27f0b799ed8e87c3cdb2c142c12afe97d252bcb338be6146378f526
03e4674d0c2091c7f408c93ea5e5d94ee231c563cecc714c24da9cd37b24b22104
03296b46f3f622d4d7f004c7c5b10f77fe3e6384358f87606ebe41b14919f7211b
```

the N-of-N aggregated key:

```
70458db6f75b129ad93878e7781eeb9ba24bf4bbd498d6a9d3f27827b25c8f81
```

### Verify the musig2 aggregated key

You can verify the musig2 aggregated key using [Clementine CLI](/essentials/using-clementine/clementine-cli.md), with the following command:

```
clementine-cli musig2-key-aggregation 024ebf6626277c974726217b20bae9fc088e7f66a530b5ea21d0d1650513a99fb0,02b0895dc582479793abb442d77e0f71bc040a7400eedb52ad4d1ce1e200be0560,0338c5e8932ed6b084f163a6d7a2b9a0af95f57d07c4c69567c0544e7fbfd93b98,034c027c18a980c76b55a99d015cb0c845eb8875f2a403ff957b7e266d0aa66e1d,02c585eb3acfff97b5d1caf73368cb9e0139fd6c42ebe4b13c68d24e9e77d9d7c7,02582cb654c6ccc6fb4cd11a6c88af83a961b918385e9f30411ca94b5395e75048,0310cc0687c18427ade30226629c30b1de5c6e714b261c4909172a6e4797f5bd51,025668e399d27f0b799ed8e87c3cdb2c142c12afe97d252bcb338be6146378f526,03e4674d0c2091c7f408c93ea5e5d94ee231c563cecc714c24da9cd37b24b22104,03296b46f3f622d4d7f004c7c5b10f77fe3e6384358f87606ebe41b14919f7211b
```

## Security Model

The signer set provides the following security guarantees:

* **1-of-N Honesty**: The bridge is secure as long as at least one signer remains honest
* **Covenant Emulation**: Pre-signed transactions ensure funds can only move along approved paths
* **No Single Point of Failure**: Multiple independent entities from different jurisdictions operate the signer set
* **M-of-N Upgrade Path**: A separate M-of-N multisig can update the N-of-N set if needed.

{% hint style="info" %}
While the N-of-N scheme provides strong security, it requires all signers to be available for certain operations like optimistic payouts. If a signer is unavailable, the protocol falls back to operator-assisted withdrawals.
{% endhint %}

## Related Resources

* [Clementine: Trust-Minimized Bitcoin Bridge](/essentials/clementine-trust-minimized-bitcoin-bridge.md)
* [Clementine CLI](/essentials/using-clementine/clementine-cli.md) - Command-line tool for deposits and withdrawals
* [Clementine Whitepaper](https://citrea.xyz/clementine_whitepaper.pdf)
* [Clementine Source Code](https://github.com/chainwayxyz/clementine)