This text is featured in Bitcoin Journal’s “The Withdrawal Problem”. Click on right here to subscribe now.
A PDF pamphlet of this text is out there for obtain.
Chaumian ecash, a privacy-preserving fee system, was conceptualized within the early ’80s and identified to be the primary cryptocurrency ever invented. Though this know-how skilled a interval of dormancy, the appearance of Bitcoin has revived curiosity on this know-how. As we stride into an period more and more involved with digital privateness, ecash is experiencing a renaissance, primarily attributable to our discovery of Bitcoin because the foundational cash layer for the web.
Cashu permits the usage of ecash on Bitcoin, empowering extraordinary customers to function a mint that’s linked to the Lightning Community. This allows everybody to supply completely personal, untraceable Bitcoin fee companies to their friends, social circles, or bigger communities.
Chaumian mints use a method often known as blind signatures, which obscure consumer actions from the custodian managing the service. Customers, upon making a fee over the Lightning Community, obtain ecash that’s saved as information items on their units, similar to bodily money. These ecash tokens, denominated in satoshis, will be exchanged between customers or be transformed again right into a fee on the Lightning Community with the assistance of the mint.
An necessary benefit of ecash is that transactions between customers can happen by way of any communication medium, equivalent to a chat shopper or a QR code, with the mint not concerned within the precise token change. This ensures the mint is oblivious to transaction specifics, together with who transacted with whom. Even throughout fund withdrawal from the mint, consumer id stays nameless.
The mixing of Cashu guarantees a realm of near-perfect privateness on the earth of Bitcoin custody. This tutorial explains how one can arrange and run a Cashu mint right this moment and change into a blinded Uncle Jim your self.

Cashu on LNbits
The simplest solution to run a Cashu mint is thru the LNbits Cashu extension. For that, you already want a Lightning node with LNbits put in. In case you are utilizing standard node distributions like Umbrel, search for the LNbits app and set up it. As soon as LNbits is about up, it takes solely a few clicks: Go to the extension overview and search for the Cashu extension and set up and allow it. You need to now see the extension obtainable for all customers of your LNbits occasion.
As a consumer, click on on the extension and create a brand new Cashu mint. Enter the main points in your mint and choose the backend pockets that will likely be used for funding the mint. That’s it! You possibly can copy the mint URL and use it with any Cashu pockets, equivalent to Nutstash.app or Cashu.me.
Beware, you’re answerable for retaining your mint operational and the deposited funds on this pockets secure. You additionally must handle your node properly such that your customers can simply make and obtain funds on the Lightning Community. Moreover, you additionally haven’t any method of figuring out the exercise of your customers. This implies you’re unable to censor anybody particularly from utilizing your mint. Chaumian mints are so privacy-preserving that censorship is virtually unimaginable.
Cashu Nutshell
Probably the most superior method of operating a Cashu mint right this moment is to make use of the reference implementation known as Nutshell. For this, you first must clone the GitHub repository and observe the directions of organising your Python atmosphere within the Readme.
As soon as your atmosphere is prepared, you must arrange your mint configuration which incorporates connecting it to a Lightning backend. At present, you should utilize any LNbits occasion as a Lightning backend (which in flip lets you use all standard Lightning node implementations). Within the close to future, additionally, you will have the ability to use your Lightning node straight with out an LNbits middleware. Nevertheless, for now, that is the really helpful method since LNbits lets you separate entry to your node’s funds to devoted wallets and thus serves as an additional layer of safety in case one thing goes flawed.
To arrange your mint’s preferences, copy the instance configuration file .env.instance to .env and edit the next entries within the file:

# Community settings
MINT_LISTEN_HOST=127.0.0.1 # Use 0.0.0.0 for public entry
MINT_LISTEN_PORT=3338
# Lightning funding supply
MINT_LIGHTNING_BACKEND=LNbitsWallet
MINT_LNBITS_ENDPOINT=https://legend.lnbits.com
MINT_LNBITS_KEY=YourLNbitsAPIKey
Notice that for those who simply need to experiment (or develop) and never join your mint to the Lightning Community, you should utilize the backend kind “MINT_LIGHTNING_BACKEND=FakeWallet” which can deal with all invoices as routinely paid. It’s nice for making an attempt issues out!
Lastly, we set some contact particulars in order that our customers can attain us in case one thing goes flawed, and we additionally set some security limits such that solely small invoices will be created on our mint.

MINT_INFO_NAME=”Bitcoin Journal’s Cashu mint”
MINT_INFO_DESCRIPTION=”Disguise your nuts with Bitcoin Journal”
MINT_INFO_DESCRIPTION_LONG=”This mint is used for a particular occasion hosted by Bitcoin Journal. Please withdraw your funds on the finish of the occasion.”
MINT_INFO_CONTACT=[[“email”,”contact@me.com”], [“twitter”,”@me”], [“nostr”, “npub…”]]
MINT_MAX_PEG_IN=10000 # 10k sats most per bill
Bear in mind which you can’t establish particular person customers. Which means, if you wish to shut your mint once more, you must give each consumer the chance to withdraw by themselves. Add the setting “MINT_PEG_OUT_ONLY=TRUE” to your configuration file in order that solely peg-outs are allowed if you wish to shut down your mint.
This text is featured in Bitcoin Journal’s “The Withdrawal Problem”. Click on right here to subscribe now.
A PDF pamphlet of this text is out there for obtain.