Guide: Running an Ecash Mint

Guide: Running an Ecash Mint

The Renaissance of Ecash: Privacy and Security in the Blockchain Era

Bitcoin Magazine

In the early 1980s, David Chaum conceptualized Chaumian ecash, the first privacy-preserving payment system, which can be considered the precursor to modern cryptocurrencies. While the technology experienced a period of dormancy, the emergence of Bitcoin has reignited interest in the concept. As we venture into an era increasingly concerned with digital privacy, ecash is experiencing a renaissance, propelled by Bitcoin’s role as the foundational money layer for the internet.

One significant development in this space is the integration of Cashu, a system that enables the use of ecash on the Lightning Network. Cashu empowers ordinary users to operate a mint, connecting them to the Lightning Network and allowing them to offer perfectly private, untraceable Bitcoin payment services to their peers, social circles, or larger communities.

Chaumian mints, like Cashu, employ a technique called blind signatures to obscure user activities from the custodian managing the service. When a user makes a payment over the Lightning Network, they receive ecash stored as data pieces on their devices, resembling physical cash. These ecash tokens, denominated in satoshis, can be exchanged between users or converted back into a Lightning Network payment with the assistance of the mint.

One remarkable advantage of ecash is that transactions between users can occur through any communication VoAGI (Voice Over Access Gateway Interface), such as a chat client or a QR code. The mint is not involved in the actual token exchange, ensuring that it remains oblivious to transaction specifics and user identities, even during fund withdrawal from the mint.

The integration of Cashu in the Bitcoin ecosystem holds the promise of near-perfect privacy for custody. Operating a Cashu mint allows individuals to enjoy the benefits of increased privacy and security. This tutorial aims to guide users in setting up and running a Cashu mint, providing them with the tools to become a blinded Uncle Jim themselves.

Cashu on LNbits

The easiest way to run a Cashu mint is through the LNbits Cashu extension. To utilize this extension, users need a Lightning node with LNbits already installed. For those using popular node distributions like Umbrel, the LNbits app can be found and installed easily. Once LNbits is set up, running a Cashu mint requires only a few simple steps. Users can go to the extension overview, find the Cashu extension, and install and enable it. The extension becomes available for all users of the LNbits instance.

As a user, simply click on the extension and create a new Cashu mint. Enter the details for the mint and select the backend wallet that will be used to fund it. That’s it! Users can then copy the mint URL and use it with any Cashu wallet, such as or

It is important to note that as the operator of a mint, users are responsible for keeping it operational and ensuring the safety of the funds deposited in the mint’s wallet. It is also crucial to manage the Lightning node efficiently so that users can easily make and receive payments on the Lightning Network. Additionally, as a mint operator, there is no way to know the activity of the users, making it impossible to censor anyone specifically from using the mint. This level of privacy preservation makes the prospect of censorship highly unlikely in Chaumian mints.

Cashu Nutshell

For those seeking a more advanced method of running a Cashu mint, the reference implementation called Nutshell is the way to go. To get started with Nutshell, users need to clone the GitHub repository and follow the instructions provided in the README file to set up their Python environment.

Once the environment is ready, users should configure the mint by connecting it to a Lightning backend. Currently, LNbits instances serve as a Lightning backend, allowing users to utilize popular Lightning node implementations. In the near future, direct integration with individual Lightning nodes will be possible without an LNbits middleware. However, for now, using LNbits is recommended as it provides an extra layer of security by allowing users to separate access to their node’s funds into dedicated wallets.

To set up the mint’s preferences, users can copy the example configuration file env.example to .env and edit the relevant entries. These entries include network settings, such as the host and port to listen on, as well as Lightning funding source details, such as the type of backend wallet and its associated endpoint. Users can find these details in their LNbits instance configuration.

In addition, users can set contact details in the mint’s configuration file, allowing users of the mint to reach out for support if needed. Safety limits can also be set to restrict the creation of large invoices on the mint.

An important aspect to consider when operating a mint is the inability to identify individual users. This means that if users decide to close down the mint, they must ensure that each user has the opportunity to withdraw their funds. By including the setting “MINT_PEG_OUT_ONLY=TRUE” in the configuration file, only peg-outs will be allowed, enabling a smooth closure of the mint.

With the renaissance of ecash and the integration of Cashu, the blockchain industry is taking a significant leap towards preserving privacy and enhancing security. The combination of Chaumian mints and the Lightning Network offers a powerful tool for individuals to transact with near-perfect privacy and anonymity.

To learn more about the withdrawal issue and access a PDF pamphlet of this article, visit Bitcoin Magazine’s website and subscribe now. Embrace the possibilities unlocked by the revival of ecash and experience the improved privacy and security offered by Cashu. The era of digital privacy is upon us, and with blockchain technology at the forefront, we can ensure that our financial transactions remain private and secure.