How privacy works

• The chain shows that a shielded transaction happened. Not who paid, who was paid, or how much.
• zhour sees what reaches its own address and how you use the GPU. It never learns your name or email, and not your wallet unless you sign in with one.
• RunPod runs the machine, so it can see what runs on it.
• Your codes are kept in your browser. Anyone who has a code can use it.

Anyone reading the Zcash chain

Sees: A shielded transaction, its fee, when it was mined, and roughly how many inputs and outputs it has.

Does not see: The sender, the receiver, the amount and the memo.

Your wallet's server

Sees: Zashi and Zingo sync through a light wallet server. It sees your IP address, and that your IP sent a transaction.

Does not see: What is in the transaction, or which payments are yours. A wallet that connects through Tor hides your IP from it.

zhour

Sees: The payment reaching zhour's address: amount, memo and time. The order it matches, the voucher, each session's start and stop times, and your IP address in the hosting logs. zhour made your machine's Jupyter password and holds it while the machine runs. If you sign in, your wallet address and the codes linked to it.

Does not see: Your Zcash address or balance. Your name or email. What you do on the machine: zhour holds its password but does not use it.

RunPod

Sees: The machine and everything on it, and the IP address you open Jupyter from. The card is rented to zhour's account, not to you.

Does not see: Who paid, or that anyone paid in ZEC.

Reown and jsDelivr, only if you sign in

Sees: The sign-in window loads from jsDelivr and connects through Reown's WalletConnect relay. Both see your IP address; Reown sees the wallet address you connect.

Does not see: Your orders, vouchers or sessions.

When you order, zhour quotes an exact amount. Its last digits are unique to your order, and a memo is attached for wallets that send one. The payment is encrypted to zhour's address, so only zhour's viewing key can read the amount and memo.

zhour's server holds a viewing key, not a spending key. It can see payments arrive and cannot move them. The key that can spend the ZEC is not on the server.

A payment that matches no order is kept on record and credited by hand. Nothing is dropped.

Order

Shows the payment status for one order.

Voucher (zv_…)

Worth your hours. Whoever has it can start them.

Session (gs_…)

Controls a machine, including stopping it. It is in the session page's address, so sharing that link shares control.

They are saved in this browser's storage. Clearing site data or using a private window loses them, unless you signed in or wrote them down.

Optional. You sign a one-time message with an Ethereum or Solana wallet. It is not a transaction and costs nothing. zhour then links your order and session codes to that address, so signing in on another device shows them.

What it costs you: zhour can now tie your GPU use to a public address, and that address may have a history anyone can read. If that matters, sign in with a fresh wallet, or do not sign in.

Sign out forgets the sign-in in this browser. Forget this wallet, in the app, also deletes the link from zhour's server. Your codes keep working either way.

• Pay from a shielded balance, which Zashi and Zingo use by default. Paying from a transparent address (one that starts with t1) puts that address and the amount on chain.
• Exchanges usually cannot pay a shielded address. Withdraw to Zashi first, then pay from Zashi.
• Swapping SOL into ZEC inside Zashi is public on Solana: the swap shows your Solana address and the amount. The ZEC payment after it is shielded.
• A VPN or Tor hides your IP address from zhour and from RunPod.

Orders, payments, vouchers, sessions and sign-in links sit in one file on the payment service's disk. They are kept because they are records of money paid. Request logs are kept by the host, Render, for its retention period.

zhour runs no analytics and sets no cookies.

Last updated 30 September 2026