> ## Documentation Index
> Fetch the complete documentation index at: https://docs.cloak.ag/llms.txt
> Use this file to discover all available pages before exploring further.

# Viewing Keys and Compliance

> Client-side key model, registration lifecycle, and chain-native history behavior

## v1 model

* Users derive viewing material client-side (`nk`) and keep private keys local.
* Transactions include compact encrypted chain notes.
* History scanning decrypts chain data with `nk` and verifies integrity from public inputs.
* Apps can cache encrypted history snapshots and trigger explicit rescan when needed.

## Registration lifecycle

1. Wallet signs a fixed Cloak sign-in challenge.
2. SDK submits the signed viewing-key registration.
3. Signature ownership is verified and the viewing key is bound to the wallet identity.

## Enforcement and UX behavior

* SDK transaction flows enforce viewing-key registration by default.
* Apps can reuse wallet sign-in sessions to avoid repeated prompts.
* If registration is missing, history/compliance views should prompt users to register and retry.

## Chain-native scanner behavior

* `scanTransactions` reads Cloak program transactions from RPC.
* Scanner extracts compact chain-note envelopes from transaction data.
* Decrypts using `nk` and verifies `chainNoteHash` integrity.
* Produces per-transaction `gross`, `fee`, `net`, and running balance.

## Trust model

* Compliance services can only process history for keys users have registered.
* Scanner-based discovery remains chain-native — history is reconstructed directly from on-chain data using the viewing key.
* Clients should never log raw viewing keys or full decrypted note payloads.