Announcing Steel Magnet: The First Meson Mixnet Testnet

By hashcloak

It's been a long time (long time), we shouldn't have left you (left you) Without a dope mixnet to protect you, protect you, protect you, protect you *

After years of hard work, we are finally announcing the first Meson testnet release dubbed Steel Magnet🎉!

Why Steel Magnet? Well, steel magnets are a core component of cyclotrons which are particle accelerators in which meson particles are built. For more details, read this Wikipedia article.

Our first testnet will be simply a local testnet in which users and future node operators alike can experience what it feels like to use Meson. You can also use our wallet demo in order to experience what it's like to send cryptocurrency transactions through Meson!

This testnet will have support for Ethereum, Ethereum testnets and major L2s such as Optimism and Arbitrum. Further, with our wallet demo, you can send your transactions privately using one of Ethereum's most popular privacy tool,! Due to interest, we are currently in talks to support other blockchains such as Firo and Solana and will be adding support for ZK-Rollups on Ethereum in subsequent testnets!

Testnet Features

This first testnet is meant to test our PKI system , Katzenmint, on a larger scale. Katzenmint is a Tendermint-based PKI system for managing mix nodes building upon the Katzenpost directory authority. This will be the first of many testnets in which we push the limits of Katzenmint.

We will be writing more about our design of Katzenmint and how it differs from other directory authorities in other anonymity systems.

The road ahead

The road to Meson will be long and we want to bring everyone along with us.

Here is a short overview of the road ahead and what other features will be included in subsequent testnets

Internal Audit

At HashCloak, we've been heads down trying to make Katzenmint work and get rid of glaring bugs out of our prototype of Katzenmint. However, since we are building upon the Katzenpost mixnet project, we will be taking the time to take a critical look at the code and seeing where it fails with respect to privacy, anonymity, and code quality. We will be writing more about the process of auditing anonymity networking software, so stay tuned.

Dynamic tuning

Mixnets are really nice in that they scale vertically and horizontally better than most anonymity systems. However, there is no free lunch. When more nodes are added, there are diminishing returns with respect to how large the anonymity sets for messages can be and latency. Add too many mix nodes and you risk the chance of making it easier to de-anonymize messages if there isn't enough traffice. Add too little nodes when traffice increases and then you risk the chance of increasing the latency of messages passing through the mixnet. In both cases, since our use case is blockchain transactions, users risk not only potentially missing out on interesting on-chain opportunities but might also lose some anonymity in the process!

This problem is commonly referred to as dynamic tuning of mix network parameters. In other words, how do we ensure that at a given time, there are enough mix nodes on the network to maximize anonymity while minimizing latency for messages that go through the mixnet? We have been working on this problem for quite a while and will soon enter the prototyping phase for our ideas and then integrate these ideas in a subsequent testnet.


Anonymity networks traditionally have relied on altruistic people running nodes for the greater good of the network. In practice, this has worked out quite well for anonymity networks like Tor. However, running these kinds of nodes is very resource intensive and we should aim to lessen the load on people who decide to participate in a cutting edge anonymity system.

With the advent of alternate funding models facilitated by cryptocurrencies, we will be experimenting with ways (beyond just launching a shitcoin!) in how to ensure that participants in Meson can be compensated!

Running the testnet

In order to run the testnet locally, do the following:

  1. Clone Meson repository $ git clone

  2. Checkout to monorepo branch $ git checkout monorepo

  3. Build containers $ python plugin/ops/

  4. Start testnet

$ cd testnet/local
$ docker compose up
  1. Execute ping test
$ cd ping
$ go run main.go -s echo

More details are available at

Keeping in touch

If you want to keep in touch with the Meson project, you can follow us on Twitter @MesonMixnet. If you want to follow the developement and research discussions, please join us on Element.

*Reference for this quote: Aaliyah – Try Again