Hi. I'd like to announce txmix, a library for writing mixnets in python. https://github.com/applied-mixnetworks/txmix txmix is GPL3 licensed and currently depends on: sphinxmixcrypto, Twisted, txtorcon, attrs, eliot and Tor Project's chutney (for integration tests). txmix allows you to write mixnets with reduced code complexity and transport agnosticism... however I've choosen to focus my development efforts on the Tor onion transport for several reasons, the onion transport has some properties which the UDP transport does not: - reliability - forward secrecy - NAT penetration Additionally the Tor anonymity properties are a welcome bonus since they aren't really overlapping with those of the mixnet, they are vulnerable to different types of attacks and accomodate for totally different threat models. Currently txmix has some integration tests that use chutney to spin up a local 25 relay tor network; builds a mixnet using onion services as the transport and then tests functionality by sending and receiving messages on the mixnet. future development ------------------ - txmix could certainly be used to write various kinds of mixnets, however, we are missing a PKI. Without some kind of public key infrastructure how will mix clients learn about mix public keys? - sphixmixcrypto library needs improvements that would allow us to specify more message types such as dummy/cover traffic message and heartbeat messages. These of course are essential for the defense against certain known active attacks against some mix types. questions, code review and pull requests welcome. David Stainton