Questions, answered straight.
Is Blink really free?
Yes. No paid tiers, no ads, no data resale. Donations are optional and fund development only.
Do I need a phone number or email?
No. Your identity is a keypair generated on your device (a DID:key). There is no account to create.
What encryption does Blink use?
The Signal Protocol — X3DH for key agreement and the Double Ratchet for per-message forward secrecy — over ChaCha20-Poly1305, with Curve25519 keys.
Is there a server?
By default yes — a single blind relay (on Cloudflare). It holds sealed ciphertext for offline delivery and never sees plaintext. Since v1.5.0 there are two experimental paths that skip it entirely: nearby Bluetooth (the message goes straight to a contact a few metres away) and Reticulum. Both are off until you enable them. Full decentralization (Tor, multi-relay) is still on the roadmap.
Is the Bluetooth feature a mesh network?
No, and we won't call it one. Messages do not hop through other people's phones — your contact has to be within Bluetooth range of you personally. It's a shortcut when you're in the same room, not a censorship-resistant network. Multi-hop is on the roadmap.
Can you read my messages?
No. Messages are end-to-end encrypted with libsignal; the keys never leave the endpoints. We could not read them if compelled to.
What about metadata?
Content is fully protected, and sealed sender hides who sent a message from the relay. Network metadata (your IP, timing, volume) is still visible to the relay — Tor transport is planned. We say so plainly rather than overpromise.
How do I recover my account?
From a 12-word recovery phrase you save during onboarding. We cannot recover it for you — that's the point.
Is the source open?
Yes — Blink is open-source under AGPL-3.0. The full source is public at github.com/tralalananala-cloud/blink. Every release also publishes a SHA-256 you can verify against the file you downloaded; reproducible builds are next.