Everything, stated plainly

There is nothing to install and nothing to sign up for. Open the app, generate a pair of keys, and you have a meta-address you can hand out for the rest of the project’s life.

1. 01Open the app. Go to the Ghost Receive tab and press Generate keys. Two private keys are created in your browser.
2. 02Back them up. Download the JSON backup, or set a passphrase so the keys are encrypted at rest on this device.
3. 03Share the meta-address. Copy the text or show the QR. It is safe to publish; it cannot spend anything.
4. 04Get paid. Every payer derives a fresh one-time address from it. Claim their receipt QR, then sweep.

RhMask implements ERC-5564 stealth addresses on secp256k1. You hold two private keys. The spending key moves funds. The viewing key only recognises which payments are yours, so it can be handed to an accountant without giving up control.

Your meta-address is the two matching public keys joined together:

st:eth:0x <33-byte spending pubkey> <33-byte viewing pubkey>
              └─ 132 hex characters in total

A sender turns that into a one-time address nobody can link back to you:

ephemeral r,  R = r·G
S        = r · K_view              (sender)   ==  k_view · R   (you)
h        = keccak256(compress(S)),  view tag = h[0]
P_stealth = K_spend + h·G
address   = keccak256(uncompress(P_stealth)[1:])[12:]

The view tag is one byte. Scanning checks it first and only does the full elliptic-curve work on a match, which is what keeps a scan fast once the announcer contract exists.

A private payment is three scans and no server. Every step happens in a browser, and the receipt QR carries the announcement until the on-chain announcer contract ships.

Both formats are plain URLs, so a phone camera opens the right screen with no app install:

Payment request
https://rhmask.org/pay?to=st:eth:0x…&token=NVDA&amount=1.5&memo=invoice%2042

Receipt / announcement
https://rhmask.org/app?claim=1&addr=0x…&eph=0x…&tag=87&tx=0x…#receive

addr is the one-time address, eph the compressed ephemeral public key, and tag the view tag. Those three fields map one-to-one onto the ERC-5564 announcement event, so the scanner will replace the QR without a format change.

Swaps are filled through an intent router rather than a public order book, so the order never sits in a mempool as a visible trade. Pick an asset from 189 across 35 chains, enter a human amount, and the quote prints the venue and the flat fee before anything is sent.

The receiving address can be a fresh stealth address derived from your own meta-address in one click, so a swap and a private receive become a single action.

Five properties hold for every release, and each one is checked rather than asserted.

• Keys never leave the device. Generation, derivation and recognition are pure client-side code. No fetch sits in the key path.
• The server holds nothing. No custody, no private keys, no session. Secrets are server-only env vars used to reach third-party routers.
• Encrypted at rest. Optional passphrase wraps the keys with AES-256-GCM, key derived by PBKDF2-SHA256 over 310,000 rounds via WebCrypto.
• Fail closed. A missing key produces a named 503, never a silent fallback that might leak or mislead.
• Verified against mainnet. A read-only script simulates real transfers from real holders before each release. It signs nothing.

What is not hidden matters just as much: on-chain settlement is public, the venue filling a swap sees the deposit and the receiving address, and your IP reaches whichever RPC you use unless you run your own node.

Found a problem? Report it privately by email rather than in a public issue. Details are in SECURITY.md.

Every route is a Next.js handler in the same deployment. Reads are cached where it is safe, and nothing that touches a key is exposed.

The pass-through exists because some networks hijack the chain’s RPC domain at the DNS level. Routing through the app’s own origin keeps balance reads and sweeps working where the direct endpoint is filtered. Batches are capped and log ranges bounded so the public RPC is not abused through us.

curl -X POST https://rhmask.org/api/rpc \
  -H 'content-type: application/json' \
  -d '{"jsonrpc":"2.0","id":1,"method":"eth_blockNumber","params":[]}'

A stealth address only protects you if you use it at the moment someone asks for an address. The extension moves that choice to exactly that moment: a chip appears beside any address field, one click pastes a fresh one-time address, and the receipt is kept locally.

It shares the key format with the app, so one backup and one passphrase work in both. It has no backend and requests no host permissions: the content script runs only on the tab where you clicked the toolbar icon.

git clone https://github.com/rh-mask/rhmask.git
cd rhmask && npm install
npm run build:extension       # bundles into extension/dist
# chrome://extensions → Developer mode → Load unpacked → extension/dist

The repository is public and the app builds with no secrets at all.

git clone https://github.com/rh-mask/rhmask.git
cd rhmask
npm install
npm run hooks:install     # pre-push gate, once per clone
npm run dev               # http://localhost:3000

Four checks back the claims on this page, and the same set runs in CI: