# Signing & approvals overview

Wallet-as-a-Service (Palisade) provides multiple layers of security controls to protect your digital assets. These controls work together to ensure that only authorized transactions are executed and that your wallet keys remain secure.

In this section
- [MPC quorums](/products/wallet/user-interface/security-controls/mpc-quorums) – Configure multi-party signing with distributed key shards
- [Approvals](/products/wallet/user-interface/security-controls/approvals) – Set up approval workflows for transactions and operations


## MPC quorums

Multi-Party Computation (MPC) quorums split wallet private keys across multiple devices, ensuring that no single device holds the complete key. When a transaction requires signing, multiple devices must participate to create a valid signature.

MPC quorums support:

- **Mobile devices**: Manual review and approval via the Palisade Mobile app
- **CloudSign devices**: Programmatic signing for high-volume operations
- **Mixed quorums**: Combination of mobile and CloudSign for flexibility


See [MPC quorums](/products/wallet/user-interface/security-controls/mpc-quorums) for configuration details.

## Approvals

Approval groups add a human authorization layer to transactions. Before a transaction is submitted to the blockchain, designated approvers must review and approve it through the web console or mobile app.

Key features:

- Configure approval groups for transactions, addresses, policies, and more
- Set minimum required approvers (e.g., 2 of 3 must approve)
- Configurable timeout periods for approval windows


See [Approvals](/products/wallet/user-interface/security-controls/approvals) for setup instructions.

## How these controls work together


```mermaid
flowchart TD
    TX[Transaction Created] --> PC[Policy Check]
    PC --> AP{Approvals Required?}
    AP -->|Yes| AG[Approval Group Review]
    AP -->|No| SIG
    AG -->|Approved| SIG[MPC Signature]
    AG -->|Rejected| REJ[Transaction Rejected]
    SIG --> BC[Blockchain Submission]
    BC --> CONF[Confirmed]
```

1. **Policies** define what transactions are allowed (amounts, destinations, frequency)
2. **Approvals** ensure human oversight before execution
3. **MPC quorums** cryptographically sign approved transactions