On Saturday, the Nym testnet underwent what’s known as a Sybil attack, where someone multiplies resource use in order to annoy a network into submission. From 11am until evening, an internet comedian was auto-scripting new nodes, so we went from about 1,600 nodes to well over 10,000 in the space of a few hours (bigger than Tor, and as big as the larger cryptocurrency systems in the world). At that point, we shut down the network monitor, so that in case the attack continued we didn’t have monitor timeouts and start accidentally penalizing good nodes.

Rewards for node operators will…

The Nym platform v0.9.2 is now available.

All mixnode and gateway operators should update their running code. Validators do not need to update for this release.

The new version should fix the networking problems that we’ve been seeing over the past few weeks, primarily due to the spectacular growth we have been seeing in mixnode numbers. We have now surpassed the 1500 node level.

We have re-enabled the network monitor which tracks node uptime / reputation. Only v0.9.2 nodes will be monitored. Older nodes will have their reputation frozen until they upgrade. So there’s no massive hurry to upgrade, your reputation is not being degraded. But the sooner you upgrade your node, the sooner your reputation will start rising again.

Thanks once again to all of our node operators!

Nym 0.9.1 code is now released!
Nym 0.9.1 code is now released!

Thanks so much to everyone who has taken the time to set up a Nym mixnode. You are now part of one of the largest privacy networks on the planet, and probably the fastest-growing one.

We have grown immensely over the past two weeks, with a 12x increase in network size. We had already been in the process of decentralising our directory server, but got caught short by the explosive growth of the network since the launch of version 0.8.0.

This release slows down metrics and presence reporting, which have been crushing the directory server. The decentralized directory server will be incorporated into all validators in our next minor release, 0.9.0.

All mixnode operators are advised to upgrade their mixnodes to 0.8.1 in the meantime.

In 0.8.1, things are a bit simpler for users:

  • new…

We are very pleased to announce the availability of version 0.8.0 of the Nym platform. It’s our biggest release ever!

Most of the work over the summer has been focused on mixnet reliability, new privacy features, and ease-of-use.

Let’s get into it.

SURBs for reliability and replies

We now have Single Use Reply Blocks (SURBs) working. SURBs allow two parties to communicate with each other while preserving their anonymity.

How are they used?


A Single Use Reply Block Acknowledgements, or SURB-ack, is now sent with every packet, giving a major boost to mixnet messaging reliability.

If Alice sends a message to Bob, the gateway node…

How can a ‘privacy-respecting’ app do ‘tracking’?

I work on an open source project which protects user privacy, so naturally my friends have recently been asking me about coronavirus tracking apps. They seemed to get some benefit from the answers, so I thought writing our discussions up might be helpful for a more general audience. If you find it helpful, please share it!

So: how is it possible to both track people and to respect their privacy at the same time?

I think it’s important to answer this question. …

We’ve built a Sphinx packet in WebAssembly!

Many privacy geeks have long regarded mixnets as one of the ultimate technologies for user privacy online. Up until now, they were the unicorns of the computer security world: you might have heard about them, but you’d never actually see one in action.

If you need a simple introduction to mixnets, I’ve previously written one. The short version: like Tor, mixnets bounce messages around between networked nodes (computers) in different locations, to obscure who is talking to who.


Mixnets do an additional thing, making them potentially even better than Tor: they shuffle packets together to re-order packets inside the nodes…

In my past few posts, I’ve talked about some of the core technologies behind Nym, the privacy project I work on.

How are we planning to apply these technologies? What’s our plan for 2020?

Broadly speaking, it looks like this:

  1. alpha — mixnet + centralised directory
  2. beta — mixnet + decentralized directory + mixmining
  3. full testnet — incentivised decentralized mixnet + credentials + service providers
  4. hardening — game of mixology and hardening of the system
  5. mainnet — the fully running system.

The mixnet alpha is what we’re running now. It launched at the end of 2019, at the Chaos Communications…

Coconuts can be weirder than you expected.

Broadly speaking, the internet privacy project I work on, Nym currently has two core technologies.

The first is a mixnet that protects transport data and metadata. Mixnets work against even very strong state/corporate level adversaries who may want to deanonymize users by recording all TCP/IP packets as they transit the internet.

The Nym mixnet fulfils the promise of end-to-end network unlinkability — not only can it protect the content of messages, it also hides who is communicating with who, and the routes taken by individual packets.

The second technology is a selective disclosure credential. We have based the Nym credential…

I work for Nym, an internet privacy company. One of our technologies, a mixnet, can defend users against even very strong adversaries, like governments or large companies. Here’s how it works, described in a non-technical way.

We have already put out quite a bit of technical documentation about mixnets and privacy, and with the upcoming release of our whitepaper there will be a lot more. Probably the easiest half-hour introduction to the technical guts of a Loopix mixnet is this Usenix presentation video, if you’re a security nerd and want to have a look at that.

But so far I…

Dave Hrycyszyn

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