Business messaging that is
actually private.
Quill is a zero-knowledge, end-to-end encrypted messenger for teams that take confidentiality seriously. Your messages, calls and files are encrypted on your device — our servers only ever see ciphertext.
Everything a private team needs
Fast, familiar messaging — without giving up an inch of confidentiality.
End-to-end encryption
Every message is protected with the Signal Protocol — X3DH key agreement and the Double Ratchet with perfect forward secrecy. Keys never leave your devices.
Zero-knowledge server
The server is a blind relay. It stores no message content, ever — undelivered messages wait as encrypted blobs and are purged the moment they're delivered.
Encrypted voice calls
Crystal-clear one-to-one calls secured with DTLS-SRTP. No one between you and the other end can listen in.
Disappearing messages
Self-destructing messages, one-time view media, and a full ephemeral mode that keeps no history on your device at all.
Private groups
Encrypted group chats with member verification, admin-only posting, and encrypted file, photo and voice sharing.
Android, iOS & Windows
Native apps for your phone and your desktop, kept in sync — with privacy-respecting push notifications that never contain message content.
Locked at the door
PIN or biometric lock before the app opens, automatic locking on inactivity, screenshot blocking, and encrypted local storage (SQLCipher).
You stay in control
Accounts are created by your own administrator — no public signup, no phone-number harvesting, no contact upload, no ads, no trackers.
Security, by design
Quill was built zero-knowledge from the first line of code — not retrofitted.
Signal Protocol
X3DH key agreement + Double Ratchet for every conversation, with perfect forward secrecy and post-compromise security.
Modern cryptography
AES-256-GCM encryption, X25519 key exchange, Ed25519 signatures — via the audited libsodium library.
Keys stay with you
Private keys are generated on your device and never transmitted. The server cannot decrypt anything, even under compulsion.
Minimal metadata
No contact-list upload, no analytics SDKs, no advertising identifiers. Audit logs hold connection metadata only.
Quill is invite-only. There is no public signup — accounts are provisioned by your organisation's administrator, so you always know exactly who can reach you. Want Quill for your team? Contact support@clareinfotech.com.