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.
Popular messengers hide a data center in the middle. You send; their server holds the line until the other phone wakes. Instant is easy when someone else is always online on your behalf.
Glitr refuses that shape. The always-online party is your git host, and git hosts are not chat servers. They accept a push when you make one. They do not ring a peer.
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.
Glitr’s encryption story has two timescales: computers we have today, and computers we may have later. A messenger that only did today’s elliptic-curve handshake would be finished for 2016. The shipped cascade adds post-quantum key agreement on purpose: ML-KEM-1024 as a standalone hybrid envelope, and PQXDH so classical X25519 and the lattice KEM ride together.
A group chat usually wants a shared place: one room, one inbox, one server that fans the line out. Glitr does not have that place. There is no shared group repository. A group is a fan-out thread: one cascaded copy per other member, written to your mailbox, tagged with the same groupId.
Encryption in Glitr is real, and it is not a cloak of invisibility. A host administrator browsing files should not be able to read “see you at 6.” They can still see file names, sizes, dates, and that the repo is busy.
