Silent Phone

Why your private conversations are never truly private with standard phone apps

Every call you make and message you send over conventional mobile networks leaves a permanent digital trail. Your carrier logs metadata, your device stores transcripts, and third parties can intercept unencrypted communications. Silent Phone by Silent Circle eliminates these vulnerabilities by providing end-to-end encrypted voice calls, video conferencing, and text messaging through a closed, zero-knowledge infrastructure. This application transforms your smartphone into a secure communication terminal that requires no trust in network operators or service providers.

Core security architecture and communication tools

Silent Phone operates on the Silent Circle proprietary encryption protocol, which implements perfect forward secrecy through ephemeral key exchange. Each communication session generates unique cryptographic keys that are destroyed immediately after the conversation ends, ensuring that even if a future key compromise occurs, past communications remain unreadable. The application routes all traffic through Silent Circle's hardened servers, which strip metadata and never store call logs, message content, or contact lists on their infrastructure.

• Peer-to-peer encrypted voice calls using ZRTP protocol with continuous authentication and visual hash verification for caller identity confirmation.
• Disappearing text messages with configurable self-destruct timers from 5 seconds to 30 days, leaving no recoverable traces on either device.
• Secure group video conferencing supporting up to 10 participants with synchronized end-to-end encryption across all active streams.
• Encrypted file transfer for documents, images, and audio recordings with automatic deletion from servers after delivery confirmation.
• Burn notice remote wipe capability that instantly erases all application data from lost or compromised devices through a single authenticated command.

Key advantages for privacy-conscious users

• Zero-knowledge architecture means Silent Circle cannot access your encryption keys, message content, or call recordings even when legally compelled.
• No phone number requirement — the application assigns a unique Silent Number that replaces your carrier-assigned identifier in all communications.
• Offline message queuing stores encrypted messages on servers for up to 30 days, delivering them automatically when recipients reconnect to the network.
• Cross-platform compatibility with identical security guarantees on Android, iOS, and desktop operating systems through synchronized encryption keys.
• Auditable open-source protocol — the encryption libraries undergo independent security audits with published results for verification by cryptographic experts.

Download mobile app now

Take control of your digital communications today. Install Silent Phone and eliminate metadata collection, prevent unauthorized access to your conversations, and communicate with absolute confidentiality across any network worldwide.

Technical disclaimer: Silent Phone requires an active internet connection via Wi-Fi or mobile data for all encrypted communication functions. Standard carrier voice and SMS charges do not apply, but data usage fees from your internet service provider may be incurred. The application offers free encrypted messaging between Silent Phone users; premium subscriptions are required for voice calls, video conferences, and advanced security features. In-app purchases include monthly and annual subscription tiers for full functionality.