OMEMO Specification Sprint
The past weekend some members of the XMPP community gathered in Düsseldorf to work on the next iteration of the OMEMO End to End Encryption Specification. All of us agree that the result – version 0.4 of XEP-0384 – is a huge step forward and better than ever!
Pitfalls for OMEMO Implementations – Part 1: Inactive Devices
In this post I want to discuss, what can go wrong when implementing OMEMO encryption and how the pitfalls can be avoided.
Closer Look at the Double Ratchet
In this post I try to explain the Double Ratchet Algorithm that drives the cryptography behind OMEMO and Signal. This is the second part of my series about the crypto behind OMEMO.
Shaking Hands With OMEMO: X3DH Key Exchange
In this blog post I take a detailed look at how the Extended Triple Diffie-Hellman Key Exchange (X3DH) works. This algorithm is part of the cryptography that drives OMEMO.
A look at Matrix.org’s OLM | MEGOLM encryption protocol
In this post I take a closer look on how matrix.org’s crypto protocols olm/megolm compare to the OMEMO protocol.
Unified Encrypted Payload Elements for XMPP
This is a proposal to extract the element encryption principle from OpenPGP for XMPP to make it applicable to other encryption protocols.
QR-Code Generator for OMEMO
I wrote a small tool that generates QR-Codes for OMEMO fingerprints.
Future of OMEMO
OMEMO brought many new faces to XMPP. However, there is quite a lot of controversy around it. Part of it are technical discussions, others are more or less of a political nature. Let me list some of them for you.
Recently there was a lot of news coverage of an alleged „backdoor“ in WhatsApp, the proprietary messaging application owned by Facebook. WhatsApp deployed OpenWhisperSystem’s Signal-protocol roughly a year ago. Now a researcher showed, that WhatsApp’s servers are able to register a new device key for a user, so that messages that the user did not…