Onboarding & PIN

Three Steps to Privacy

When you first connect a wallet, Dust walks you through a three-step onboarding wizard. Each step builds on the last to create a fully functional stealth identity:

1. Set your PIN — derives your cryptographic stealth keys from a wallet signature
2. Choose a username — registers a human-readable name (e.g. alice.dust) mapped to your meta-address
3. Activate — publishes your ERC-6538 meta-address on the stealth registry so others can compute stealth addresses for you

Step 1: Set Your PIN

Your 6-digit PIN is the cornerstone of your stealth identity. Together with a deterministic wallet signature, it derives all the private keys that control your shielded funds.

1. 01

   Wallet signs a deterministic message

   The app requests a signature over a fixed message. This signature is the same every time for the same wallet, providing a stable entropy source without storing any secret.

2. 02

   Signature + PIN enter PBKDF2

   The signature and your 6-digit PIN are combined and fed into PBKDF2 with 100,000 iterations and a versioned salt (v2). This produces two independent 32-byte seeds: a spending seed (salt: Dust Spend Authority v2) and a viewing seed (salt: Dust View Authority v2).

3. 03

   Seeds become BN254 scalar keys

   Each seed is hashed with Poseidon and reduced modulo the BN254 scalar field order. The spending seed becomes spendingKey = Poseidon(spendingSeed) mod p and the viewing seed becomes nullifierKey = Poseidon(viewingSeed) mod p. These keys operate within the BN254 curve used by the ZK circuits.

4. 04

   Keys held in memory only

   Derived keys are stored in a React ref — never in component state or localStorage. They exist only for the duration of the browser session and are cleared when the tab closes or the wallet disconnects.

Step 2: Choose a Username

Your username is a human-readable stealth name that maps to your meta-address on-chain. Instead of sharing a long hex address, you can tell someone to send funds to alice.dust.

• Names must be lowercase alphanumeric (plus - and _)
• The app checks availability in real time with a debounced lookup
• Once registered, the name is permanently associated with your meta-address via a relayer API

Step 3: Activate Stealth Keys

Activation publishes your ERC-6538 meta-address — a pair of public keys (spending + viewing) — on the stealth registry contract. This on-chain registration allows anyone to:

• Look up your public keys by wallet address or stealth name
• Compute a fresh stealth address using ECDH to send you funds privately
• Announce the payment so only you can detect and claim it

The wizard retries ERC-6538 registration up to 3 times with exponential backoff to handle transient RPC failures, especially for Privy embedded wallets.