> ## Documentation Index
> Fetch the complete documentation index at: https://whisper-bot.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Privacy & Security

> How Whisper Bot uses zero-knowledge proofs to make transfers private and unlinkable.

## How privacy works

Solana transactions are fully public. Anyone can trace the flow of SOL from one address to another. Whisper Bot breaks this link using a **zero-knowledge privacy pool** — a smart contract that accepts deposits and issues withdrawals without revealing the connection between them.

```mermaid theme={null}
graph TD
    A[Your wallet] -->|deposit| B[Temp address]
    B -->|deposit| C[ZK Privacy Pool]
    C -->|withdrawal| D[Recipient wallet]
    style C fill:#9945FF,color:#fff
```

**What's visible on-chain:**

* Your wallet sent SOL to a temporary address
* That temporary address deposited into the privacy pool
* The recipient's wallet received SOL from the privacy pool

**What's NOT visible on-chain:**

* Any link between your deposit and the recipient's withdrawal
* Which deposit funded which withdrawal
* That you and the recipient are connected in any way

***

## Zero-knowledge proofs

The privacy pool uses **zero-knowledge proofs** — a cryptographic technique that lets someone prove a statement is true without revealing any underlying data.

When Whisper Bot withdraws funds from the pool, it generates a ZK proof that says:

> *"I know a valid deposit in this pool that has not been withdrawn yet, and I'm authorized to withdraw it."*

The Solana program verifies this proof on-chain. It confirms the withdrawal is legitimate without learning which deposit it corresponds to. The proof reveals nothing about the sender, the deposit transaction, or the timing.

***

## The anonymity set

Privacy in a pool-based system depends on the **anonymity set** — the number of deposits that a withdrawal could plausibly be linked to.

* Every deposit into the privacy pool grows the anonymity set
* When you withdraw, an observer knows the funds came from *one of* the deposits in the pool, but not *which one*
* The more deposits in the pool, the stronger the privacy guarantee

<Info>
  Whisper Bot uses the same PrivacyCash privacy pool as the public PrivacyCash protocol. Your transfers share an anonymity set with all other users of the pool — not just Whisper Bot users.
</Info>

***

## Ephemeral keypairs

Every transfer uses a **fresh, one-time keypair** for the temporary deposit address. This keypair:

* Is generated randomly for each transfer
* Is encrypted with **AES-256-GCM** and stored only until the transfer completes
* Is never reused across transfers
* Cannot be linked to your Telegram account or wallet

After the transfer completes (or is cancelled), the keypair is no longer needed. The temporary address becomes an empty, abandoned Solana account with no connection to you.

***

## Threat model

No privacy system is perfect. Here's an honest assessment of what Whisper Bot protects against and what it doesn't.

### What Whisper Bot protects against

<AccordionGroup>
  <Accordion title="On-chain analysis">
    A blockchain observer cannot link your deposit to the recipient's withdrawal. The ZK proof reveals no information about which deposit was used.
  </Accordion>

  <Accordion title="Recipient learning your wallet">
    When you send to a Telegram user, the recipient never sees your wallet address or the temporary deposit address. They only see a claim notification.
  </Accordion>

  <Accordion title="Sender learning recipient's wallet">
    When a peer claims funds, they provide their wallet address directly to the bot. The sender never sees it.
  </Accordion>
</AccordionGroup>

### Known limitations

<AccordionGroup>
  <Accordion title="Timing correlation">
    If you deposit and the recipient withdraws seconds later with no other pool activity in between, a sophisticated observer could guess they're related. The larger the pool's activity, the less useful timing analysis becomes.
  </Accordion>

  <Accordion title="Amount correlation">
    If you deposit exactly 1.23456789 SOL and a withdrawal of \~1.22 SOL appears shortly after, the unusual amount could narrow the match. Standard amounts provide better privacy.
  </Accordion>

  <Accordion title="Telegram metadata">
    Whisper Bot knows both the sender's and recipient's Telegram IDs. This is necessary to deliver notifications. Whisper Bot does not log or store the association between transfers and wallet addresses after completion.
  </Accordion>

  <Accordion title="Relayer visibility">
    The PrivacyCash relayer processes ZK proofs and submits transactions. It sees the withdrawal address and proof, but cannot determine which deposit funded the withdrawal.
  </Accordion>
</AccordionGroup>

***

## What Whisper Bot stores

Whisper Bot maintains a secure local database to track transfer states. Here's what's stored and what isn't:

| Data                              | Stored?              | Purpose                                      |
| --------------------------------- | -------------------- | -------------------------------------------- |
| Telegram user ID                  | Yes                  | Identify users, send notifications           |
| Transfer status                   | Yes                  | Track deposit/withdrawal progress            |
| Deposit amount                    | Yes                  | Calculate fees and delivery amounts          |
| Temporary address (encrypted)     | Yes, until complete  | Execute the transfer                         |
| Recipient's wallet address        | Only during transfer | Needed for ZK withdrawal, not retained after |
| Sender's wallet address           | No                   | Never collected                              |
| Link between sender and recipient | No                   | Not recorded                                 |
| Transaction signatures            | Yes                  | Verify completion on-chain                   |

<Warning>
  Whisper Bot is a privacy tool, not an anonymity tool. It breaks the on-chain link between sender and recipient, but the bot operator knows both Telegram accounts are involved in a transfer. If you need anonymity from the bot operator, this is not the right tool.
</Warning>

***

## Privacy tips

<CardGroup cols={2}>
  <Card title="Use round amounts" icon="coins">
    Deposits of 1, 2, or 5 SOL blend in better than 1.73829 SOL.
  </Card>

  <Card title="Wait before claiming" icon="clock">
    If you're the recipient, waiting a few minutes before claiming reduces timing correlation.
  </Card>

  <Card title="Don't reuse wallets" icon="rotate">
    For maximum privacy, use a fresh wallet address when claiming funds.
  </Card>

  <Card title="Avoid tiny transfers" icon="minimize">
    Very small transfers (under 0.05 SOL) have fewer pool participants at similar amounts, reducing the anonymity set.
  </Card>
</CardGroup>