Echomix blog on EchoMix

Katzenpost threat model document

Thu, 25 Apr 2024 00:00:00 +0000

Here we present a draft of the Katzenpost mixnet threat model document. We regard the threat model document as a living document which is frequently edited and in need of ongoing maintenance as we continue to develop newer mixnet protocols. Currently it is being organized by mixnet attack category and we have arranged attacks in a table with corresponding attacker capabilities. Later sections of the document present a deep dive into the core cryptographic protocols that comprise Katzenpost, namely these three:

Mixnet Literature Overview

Mon, 15 Apr 2024 00:00:00 +0000

We are presenting our overview of existing Mixnet literature. It takes some liberties with what is included or not. It proposes new ways to talk about some issues, and provides a critical analysis of some of the existing papers. It also endeavors to introduce the reader to the language of anonymity systems, while maintaining mathematical rigor.

This doc, in particular, does not talk about the Katzenpost design. It does introduce the reader to some of the reasons why we’ve been making certain design decisions, and a keen eye might be led to some of the similar conclusions. But here we focus on already published research. We also stick to theory and don’t focus on any practical systems being built today.

hpqc - hybrid post quantum cryptography library

Fri, 12 Apr 2024 00:00:00 +0000

The Katzenpost developement team has recently released a new golang cryptography library known as hpqc. The theme of the library is hybrid post quantum cryptographic constructions, namely:

hybrid KEMs (key encapsulation mechanism)
hybrid NIKEs (non-interactive key exchange)
hybrid signature schemes

In each of the three main subdirectories, “kem”, “nike” and “sign” there exists interface definitions for Scheme, PrivateKey and PublicKey. For signature schemes and KEMs we’re borrowing the interface sets from cloudflare’s circl library.

Katzenpost at 37C3

Sun, 28 Jan 2024 00:00:00 +0000

Dr. Eva Infeld and surveillance expert and developer Leif Ryge held a session at the Chaos Communication Congress about the current state of the project, some of the things we’re working on, and some of the pitfalls many anonymity systems fall into. Building an anonymity system fit for our dystopian age is a hard problem, but we’re doing it.

Audio Engineering Considerations for a Modern Mixnet

Sat, 25 Nov 2023 00:00:00 +0000

Modern Mixnets have a unique set of requirements when it comes to processing audio. The bandwidth is scarce, but we expect to use modern devices and have ample processing power. We aim to secure the communication against even sophisticated attacks that come from capturing the metadata, and prioritize tools that are free, open source and written with security in mind. In this unique setting, we present a set of recommendations for implementing codecs, DSPs, and sophisticated noise reduction tools, to deliver either impressive quality at low bandwidth or good quality at impressively low bandwidth.

Website Relaunch and migration to Hugo

Fri, 24 Nov 2023 00:00:00 +0000

To match all the code development in Katzenpost in the last year, it was time for a website relaunch. Our site was a migration from Sphinx, which is primarily for documentation, to Hugo which is wildly configurable for all sorts of websites. Given the technical nature and need for nice documentation interface, we used the well crafted and maintained Docsy theme.

Website Dependencies

Hugo static site generator
Docsy theme for Hugo
Bootstrap 5 is bundled in Docsy
Decap CMS for a user-friendly GUI

Monthly News Update (May 2019)

Sat, 04 May 2019 00:00:00 +0000

Greetings,

The last few weeks have been very busy. I now have the basic working prototype implementation of a new Katzenpost messaging system. This new system has mutual location hiding properties for communication partners because recipients retreive their messages from a remote spool using a Sphinx SURB based protocol. SPHINX SPHINXSPEC

Monthly News Update (April 2019)

Wed, 10 Apr 2019 00:00:00 +0000

Greetings,

The Panoramix grant project funded by the European Commission has officially ended but the Katzenpost free software project lives on. Masala and I continue to work on Katzenpost for grant money given to us by Samsung.

We recently learned a few things about mixnet design in a series of design meetings. The conclusions from our learnings is too much information and detail for this here post. However I will summarize some of our conclusions below. Our discussions usually revolved around mixnet CRDT applications, client reliability, message spool server design, client decoy traffic and, preventing attacks: statistical disclosure and active confirmation attacks.

Rustification

Sun, 13 Jan 2019 00:00:00 +0000

Hi,

I wrote some notes about making mixnet components in Rust that are binary compatible with existing Katzenpost components

Rustification

The goal should be binary compatibility with the golang implementation of Katzenpost such that the existing golang components can interoperate with the new Rust components. Perhaps the biggest advantage of using Rust would be for writing mixnet clients as opposed to mix servers. A Rust mixnet client could easily present a FFI that could be used by user interfaces written in Java for Android and Swift for iOS.

Monthly News Update (Nov 2018)

Thu, 22 Nov 2018 00:00:00 +0000

Greetings!

This is our second edition of katzenpost news. There’s been a lot of progress since the last report I posted many months ago.

Firstly I’d like to mention our future development plans:

mix and directory authority key agility
generative testing for the voting Directory Authority system
generative testing for all of the things where appropriate
load and performance testing the mix server
design and development of an application agnostic mixnet client message oriented protocol library
design and development of one or more applications that use our new mixnet protocol client library
potentially assist in integration with other software projects that want to use a mixnet transport protocol

Our recent accomplishments include:

Monthly News Update (Feb 2018)

Tue, 27 Feb 2018 00:00:00 +0000

katzenpost monthly news

Greetings!

This is our first edition of katzenpost monthly news. I’ll be summarizing recent events from our first hackfest in Athens in early December 2017 to the present.

What we did in Athens:

setup a test mix network
remote collaboration with Yawning Angel to fix bugs and add features to the server side
wrote some basic installation documentation
Moritz created and deployed the katzenpost website with glossary and FAQ
explored technical issues related to python and java language bindings to golang libraries
discussed at length the possibilies for various kinds of mixnet clients
Vincent wrote a prototype android instant messenger client
met with the GrNet people and told them how to install a katzenpost mix network and answered their questions
meskio and kaliy added an external user db interface for Provider authentication
meskio wrote prototype python clients for testing purposes
we had many group discussion about mix network design
special guest visitor: George Kadianakis from Tor Project

Since that time we have been working on our PKI specification. Nick Mathewson sent us a six page review of our spec and Yawning sent a two page reply; both of these e-mails contain lots of design details and have been useful in our editing of the spec thus far: