Observed arrival · 2026-08-26
OFF Castle: The Messenger That Starts With a Physical Die
An encrypted messaging app whose homepage says its conversation keys are generated from twenty-one physical die rolls, rather than held by the company or a server.
Field notes
OFF Castle describes a per-conversation key-generation process based on twenty-one physical die rolls, with the resulting entropy combined with post-quantum cryptography. Its stated architecture leaves the server as an encrypted-data router rather than a holder of keys. The page positions the app for communications involving legal privilege, source protection, financial value, or political sensitivity, and explicitly frames Signal as a comparison point rather than an opponent for mass-market use.
Observed signals
Read the marks
Editorial observations of this landing page, not a rating.
One card from the complete issue