Most messengers sell you a company inbox. You register a phone number, they hold the thread, and you hope they stay solvent, honest, and online. Glitr is a private messenger for people you already trust. There is no Glitr account, no phone-number directory, and no central server that stores your conversations.
One lock is a single failure mode. A messaging app that only did today’s elliptic-curve handshake would be finished for 2016. Glitr encrypts to a person with five independent wraps on the same payload: AES, then Signal, then PQXDH, then RSA hybrid, then ML-KEM.
The Signal Protocol was designed around a server that hands out prekey bundles and stores undelivered ciphertext. Glitr has no such server. Two people still need a classical handshake and a ratchet — the machinery that lets them agree on keys and keep advancing them so old messages stay gone if a key leaks later.
