Private messaging. Your data, your control.
Signa is an end-to-end encrypted messenger for iOS. We don’t own your messages, your photos, or your account — you do, and the architecture is built around keeping it that way.
Download on the App Store Read the privacy policy
End-to-end by default
AES-256-GCM content, Curve25519 key agreement, Ed25519 signatures. Only the people in your group can read what you send.
You own every message and photo
Signa never holds plaintext copies. Encrypted message envelopes pass briefly through Apple’s secure cloud infrastructure with a short retention window, then are removed.
Photos go to your Drive
Attachments upload to your own Google Drive or Yandex Disk via OAuth sign-in. Signa asks only for per-file access to what it creates — it never sees the rest of your Drive.
Keys stay on your phone
Device and group keys live in the iOS Keychain, protected by the Secure Enclave. They never leave the phone that generated them.
Calls go peer-to-peer
Voice and video calls flow directly between devices over WebRTC. No server, ours or anyone else’s, sits in the media path.
No tracking, no ads, no analytics
Signa contains no third-party SDKs for advertising or behavioral analytics. What the app does is what the app does.
How it works, briefly
When you create or join a group, Signa generates a fresh symmetric key for that group on your device and shares it, encrypted, with the other members’ devices. Every message is encrypted on your device with that key before it leaves — nothing else has the ability to read it.
Encrypted message envelopes are placed on Apple’s secure cloud infrastructure (the same infrastructure that handles your iCloud account) so peers can pick them up even when they’re not online at the same time. We treat that infrastructure as untrusted: we put only ciphertext on it, and each envelope is removed after a short retention window. Voice and video calls run peer-to-peer over WebRTC, with no server in the media path.
Photo attachments are uploaded directly to your Google Drive or Yandex Disk, whichever you choose to sign in to. Signa requests only per-file access — it sees the files it creates and nothing else — and the files are shared with the rest of your group through a per-file link with end-to-end encrypted metadata. The storage, the quota, and the ownership are yours.
Because there is no central server holding your conversations, losing access to your device means losing access to the history on that device. That is the tradeoff for not trusting anyone else with your messages.
Legal & support
Legal documents
Privacy Policy — what the app does and does not touch.
Terms of Service — the rules of using Signa.
Contact
For support, bug reports, or legal inquiries, email support@bluecouchworks.com.