Secure Communication, Simplified
End-to-end encrypted messaging, voice, and video calls — secured by an independent implementation of the Signal Protocol. Plus optional VoIP subscriptions for PSTN calling. Your conversations stay private. Always.
Why Cyfero?
Built from the ground up with privacy as the foundation — not an afterthought.
End-to-End Encrypted
Every message, every in-app call — secured with our independent implementation of the Signal Protocol. Only you and your recipient can access your conversations.
Zero Knowledge Architecture
Our signalling server relays encrypted data it cannot decrypt. We have zero access to your message content — mathematically guaranteed. No telemetry, no data sharing, no exceptions.
Cross-Platform
Available on Android, iOS, and Web. On Android, Cyfero can serve as your default messaging and dialler app, unifying SMS, calls, and encrypted communication in one place.
Free Communication. Optional Telephony.
Cyfero's core features — encrypted messaging, voice calls, and video calls — are free for all users. For those who need it, optional VoIP subscriptions bring PSTN calling to any phone number worldwide.
Encrypted Communication
Secured with the Signal Protocol (X3DH key agreement + Double Ratchet algorithm). Cyfero's implementation is built independently based on the openly published protocol specifications.
- End-to-end encrypted text, media, and file sharing
- Encrypted voice and video calls via WebRTC with SRTP
- Forward secrecy and post-compromise security
- Safety number verification for contact identity
- Cross-platform availability (Android, iOS, Web)
VoIP PSTN Calling
A recurring subscription that connects Cyfero to the public switched telephone network (PSTN), enabling calls to landlines and mobile numbers worldwide via standard telephony infrastructure.
- Dedicated VoIP number provisioning
- Outbound and inbound PSTN calls from any Cyfero app
- International calling with transparent per-minute rates
- Recurring billing with self-service subscription management
- Managed via the Cyfero management portal
VoIP PSTN calling uses standard telephony infrastructure and is separate from Cyfero's Signal Protocol-based encrypted communication.
Built for Security
Every layer of Cyfero is engineered to protect your privacy.
Signal Protocol (X3DH + Double Ratchet)
Forward secrecy and post-compromise security via cryptographic ratcheting. Each message uses a unique encryption key. Independently implemented from the openly published protocol specifications.
Independent Infrastructure
Self-hosted signalling servers in privacy-respecting jurisdictions. No third-party service providers have access to user communications. Zero telemetry. Zero data sharing.
Transport Layer Hardening
TLS 1.3 with certificate pinning, encrypted DNS resolution (DoH), and traffic normalisation via WebSocket frame padding to prevent traffic analysis.
Adaptive Connectivity
Proxy support, dynamic endpoint discovery, and resilient connection management for reliable communication in any network environment. Designed to function smoothly on hardened operating systems.
Your Default Communication App
On Android, Cyfero is designed to be your primary messaging and dialler app. Manage your day-to-day SMS, call history, and encrypted Cyfero conversations from a single, unified interface. Encrypted messaging and calling features are available in settings for users who choose to enable them — never forced.
- SMS management via platform-native content resolver
- Native call history integration with network dialler
- Respects privacy-hardened Android environments
- Graceful degradation when permissions are not granted
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Ready for Private Communication?
Join Cyfero and take control of your digital conversations. No ads, no tracking, no telemetry, no compromises.