delta.chat advertises that they provide “🔒 Audited end-to-end encryption safe against network and server attacks”, but if you click through it turns out that supposed audit:
(1) didn’t actually cover their e2ee but only a key establishment protocol and
(2) wasn’t actually an audit. Instead, unprompted, some researchers took a look at that key establishment protocol and found 20(!!) separate flaws. This research was not intended as an audit, nor was it commissioned or paid by delta.chat.

