Posted on
in
Matrix
• 2716 words
• 13 minute read
Tags:
Cryptography, E2EE, Megolm, Encryption, Integrity, Verification, Ratchet
In Matrix, message security is provided by Megolm. The goal of message security is twofold. We (a) want messages to be encrypted on the sender’s device and (b) only be able to be decrypted on devices of users who are a part of the conversation. As a corollary, we want to prevent other parties (rogue homeservers, man-in-the-middle attackers, etc.) from decrypting the messages. In this article I describe Megolm1, and explain what security guarantees it provides and how it provides them. I will be focusing on Megolm itself, rather than on Olm as there are already many resources for learning about Olm (the Signal Double-Ratchet Algorithm). Read more...