Post-quantum encryption protects your messages against attackers who will one day have powerful quantum computers. Here is what it is, why it matters and how Panthera uses it.
Today’s encryption relies on math problems that normal computers cannot solve in any reasonable time. A large quantum computer could solve some of them quickly, breaking the key exchange that protects most private communication today.
Attackers can record encrypted traffic today and keep it until a quantum computer is available. Post-quantum encryption makes sure what is recorded today stays unreadable in the future.
Panthera combines X25519, proven classic cryptography, with ML-KEM-768, a standardized post-quantum algorithm. Both must be broken to read a message: today’s attackers hit X25519, a future quantum computer also hits ML-KEM-768.
Every device signs its own hybrid key and keeps 25 signed one-time post-quantum keys ready. Each new conversation uses one of them, and every new ratchet step adds a fresh post-quantum secret while old keys are erased.
Classic starts are refused once post-quantum is active, and tampered or replayed messages are rejected. Safety number v2 covers both identity keys and the post-quantum device context, so you can verify it by QR code.
Sealed sender, padding to fixed sizes, per-device delivery and no recovery all remain. The server still sees only encrypted data — never text, media, sender, alias or keys.
Open the app → Settings (gear icon) → Enable Post-Quantum Encryption. Do this on every device you use; your contacts must enable it on their devices too. When both sides are protected, a Post-Quantum label appears in the chat header.
We let every user choose. Without post-quantum encryption, your messages remain protected by proven classic end-to-end encryption today. However, encrypted traffic recorded now could become readable in the future once powerful quantum computers exist. Enabling it protects your conversations for the years ahead.
Panthera is making big steps towards becoming the most advanced and secure messenger available.
