Prove a payment

Private sends hide the sender by default. But sometimes you want to prove you paid someone — an invoice, a refund, a receipt. Murk lets you optionally attach a proof to a payment and share it later, without giving up any of your other privacy.

Send with a proof

1. In Send, tick "Attach a payment proof" (and add an optional memo) before sending.
2. That's it — the payment goes out privately as usual. Murk keeps a small private receipt so you can generate the proof whenever you need it.

If you don't tick the box, nothing is kept — you stay hidden and the payment can't be proven. It's fully opt‑in.

Generate & share a proof

1. Open Proofs → My payments. Each provable payment is listed.
2. Press Generate proof to produce a compact code (murkpay1_…) you can copy and send to anyone.
3. "Sign proofs with my wallet" is on by default, so the proof also names you (your wallet address) as the sender. Untick it to stay an anonymous sender.

The one-time key behind every proof is derived from your spend key, not stored — so a proof for any past payment can be regenerated on any device (see Your history).

Verify a proof

Anyone can check a proof — no wallet or account needed:

1. Open Proofs → Verify a proof and paste the code.
2. Murk shows a verified card: amount, token, recipient, and date — and whether it was signed by a named sender.

How it works (and what it reveals)

Every private note is locked with a one‑time key that only the sender holds. A payment proof reveals just that one key. The verifier uses it to open only that single note on‑chain, confirm it's real, and read exactly what was paid to whom and when.

• It proves one payment — nothing else about your wallet, balances, or history.
• Your spend key is never exposed — the one‑time key can't be used to spend or to open any other note.
• Verification is independent: it just reads public on‑chain data.

Good to know

• The proof is a shareable code — treat it like a receipt. Sharing it reveals that one payment to whoever you give it to.
• Signing with your wallet turns "someone sent this" into "you sent this," at the cost of revealing your public address on that receipt.

ℹ️ Note: This is Murk's take on Monero's transaction‑key proof, adapted to shielded notes — it needs no special on‑chain support.