> For clean Markdown of any page, append .md to the page URL.
> For a complete documentation index, see https://docs.adid.dev/llms.txt.
> For full documentation content, see https://docs.adid.dev/llms-full.txt.

# Wallet MPC Topology

**Used in:** §8.1 Wallet Architecture
**Audience:** Holder, Backend Developer
**IA ID:** D16

```mermaid
graph TB
  classDef device fill:#dbeafe,stroke:#1d4ed8
  classDef cloud fill:#dcfce7,stroke:#15803d
  classDef recovery fill:#fef9c3,stroke:#b45309

  subgraph Phone["User device (Expo wallet)"]
    Share1["Key share 1 (secure enclave)"]:::device
  end
  subgraph Server["IDA platform"]
    Share2["Key share 2 (HSM-backed)"]:::cloud
  end
  subgraph Recovery["Recovery custody"]
    Share3["Key share 3 (encrypted, social recovery)"]:::recovery
  end

  Phone -- "MPC sign request" --> Server
  Server -- "partial signature" --> Phone
  Phone -- "aggregate" --> Sig["Final Ed25519 / secp256k1 signature"]
  Recovery -.->|"used only on recovery"| Phone
```

**Reading guide:** A normal sign uses shares 1+2 (t-of-n = 2-of-3). Share 3 is dormant until recovery is invoked. No single party can reconstruct the key.

***