Vesper

As private as cash, as global as the internet.

Code: https://github.com/vesperorg/vesper - Site: https://vesperorg.github.io/vesper/

Vesper is a privacy cryptocurrency on its own new blockchain (not a token on someone else's), built to outdo both Monero and Zcash. It is money you can use without anyone watching what you earn, what you spend or who you pay, and without having to explain where every coin came from as if you were under investigation. Cash once gave people that freedom, but cash cannot reach someone on the other side of the world. Vesper is built to be its modern, legitimate successor: privacy that is never optional, for everyone, on every payment.

How it works

Like Bitcoin, Vesper is money kept on a shared record by a network of ordinary computers instead of a bank. Unlike Bitcoin, that record proves every payment is genuine without showing who paid, who was paid, or how much:

1. A fresh lock for every payment. Your address is never written on the record. Each payment to you goes into a brand-new one-time lock that only your wallet recognises, so two payments to you look completely unrelated.
2. Sealed amounts. Every amount is sealed like an envelope that the network can add up but never open. It can still check that nobody spent more than they had, and a short proof stops anyone from printing money with a "negative" amount.
3. A crowd of 48. When you spend, your payment points at a ring of 48 coins, yours and 47 others, and proves you own one of them without saying which. A one-way "spent" stamp stops anyone from spending the same coin twice.
4. A quiet hand-off. Your computer does not announce your payment to everyone. It passes it quietly through a few other computers first, so the one that announces it is not yours. For more, Vesper can send all its traffic through Tor.

Your balance and your payments stay yours. A read-only view key lets you show them to whoever you choose, such as an accountant, without giving anyone the power to spend.

Where it stands today, honestly: it is Monero's design with three times Monero's ring, so a payment hides among 48 coins, not yet among everyone. It is not audited. It runs as a public test network, testnet-2, whose coins, tVESP (addresses start tvsp), are test coins with no value, ever: anyone can try it, try to break it, and help make it solid before it ever carries real money.

Why Vesper

• Nothing to see on the chain, and nothing to opt into. No addresses, no payment amounts, no balances on the public record. Zcash made privacy a choice, most people never chose it, and the few who did stand out. On Vesper there is no public payment at all, so everyone shares the same crowd.
• Three times Monero's crowd, measured in public. Every payment hides among 48 coins, three times Monero's 16. We test how often an attacker who knows how people really spend can pick the real coin: 2.1%, the same as a pure guess (1 in 48). The crowd holds up.
• Private, not unaccountable. Hand your accountant a read-only view key, or prove one payment to one shop with a receipt, and reveal nothing else. Both are built in, one command each.
• Measured, not promised. 47 public checks run on every change, a public page lists every weakness we know of, and the network leak comes with a number instead of a slogan.
• A fair launch. No coins made in advance and nothing for sale: every coin is mined, from block one, by whoever shows up with an ordinary computer. The first block names a Bitcoin block that did not exist until launch day, so nobody could have mined in secret beforehand.

Why we are doing this

There is nothing to buy and nothing for sale, not yet even a coin worth anything, because Vesper first has to be as secure and as private as it can possibly be. This is not a joke or a game to us. We want real privacy in our money and our payments, without being asked to account for every coin we receive or send. Your pay, your rent, your doctor and your donations are your business: with a public coin like Bitcoin, one payment to a shop is enough for that shop to follow your wallet forever. And privacy only works when everyone has it. On coins where it is optional, the few who use it stand out; on Vesper every payment is private, so everyone hides in the same crowd.

What the shared record shows

	Bitcoin	Vesper
Who was paid	visible to everyone	hidden
How much	visible to everyone	hidden
Who paid	visible to everyone	hidden among 48 possible payers
Your balance	anyone can look it up	only you, and anyone you give your view key

Made for everyday use

• One address per person. Give each person or shop their own address. They all land in one wallet, and nobody can tell they belong together.
• A recovery code on paper. Your wallet is 55 characters you can write down. Lose your computer, keep your money.
• Receipts when you need them. Prove one payment to one person, such as a shop that says it never arrived, without revealing anything else.
• A read-only key for your accountant. It shows your incoming payments and amounts, and can never spend.
• Mining on an ordinary computer. Vesper's mining is built so a normal PC can take part, not just warehouses of special machines.
• A mining pool with no company in it. Your node mines together with everyone else's and small rewards land straight in your wallet, steadily. Nobody holds your coins, nobody learns your address, and nobody chooses which payments get in.
• A reward that never runs out. No halving days: the reward slides down smoothly, then settles on a small amount forever, so miners are always paid to protect the chain.

Try it in five minutes

New to all this? START_HERE.md walks you through it step by step.

You need Python 3.10 or newer.

1. Download the code: the green Code button above, then Download ZIP, and unzip it.
2. Install the two helpers it needs: pip install -r requirements.txt
3. Double-click testdrive.bat (or run python testdrive.py).

It starts two throwaway nodes on your computer, sends private payments between them, searches the raw record for the names and amounts (and finds nothing), tries to cheat five different ways, and shows each attempt being refused. Nothing of yours is touched, and it cleans up after itself. python testdrive.py --more also shows extra addresses, the recovery code and a payment receipt.

Join the test network

Step	Double-click	What happens
1	selftest.bat	47 checks that try to break the rules: double spending, forged signatures, counterfeit coins, rewritten history.
2	wallet.bat	Makes your wallet and shows your address (tvsp...) and your recovery code. Write the code on paper: it is your wallet.
3	start_node.bat	Starts your node. It joins the network and mines test coins for you, in the pool.
4	explorer.bat	Watch new blocks arrive, and see that no payment shows a name or an amount.
5	wallet.bat	Your balance. To pay someone: python coin.py send THEIR-ADDRESS AMOUNT

New coins can be spent 10 blocks after they arrive, about 5 minutes. A new node finds the network by itself through the public seed node listed in config.json (http://207.148.85.83:8880).

Check the fair start yourself. The network is called testnet-2. Its first block names Bitcoin block 973,926 (00000000000000000001abe5bb923ff5f8a03586035bf86d8cc99bc1afb0863d), which did not exist until minutes before launch. The first block's own ID is 279154894011bf19ef475da897b9d90777fec2e5216e4786987f55ad86ff1699, and every node checks it.

Honest status

• This is a test network. tVESP coins have no value and never will. A real network, if there is one, will start fresh with its own first block and its own addresses.
• Nobody independent has checked the cryptography yet. Do not trust Vesper with real money. Before that: a stronger way to hide the payer among everyone instead of 48, a review by an independent cryptographer, and legal advice.
• The network can still give hints. Someone who runs many of the network's computers can sometimes guess where a payment started, and we measure how often (see TECHNICAL.md). If your internet address matters, run your node through Tor (--proxy).
• Still visible to everyone: the fee (the same for everyone), mining rewards, how many coins a payment uses, which block it is in, and the 48 coins it points at.

How fast is it

• Making a payment takes about a quarter of a second on an ordinary PC.
• A node checks a payment in under a tenth of a second.
• A new block comes about every 30 seconds.

Learn more

• TECHNICAL.md: how each part works, the leaks measured, the speed table, and every command.
• DECISIONS.md: every design choice and why it was made.
• deploy/: running an always-on seed node on a rented server.
• Found a weakness? See SECURITY.md. Want to help? See CONTRIBUTING.md. License: MIT.

The code is plain Python, written so that each trick can be read and followed line by line.