Technology
Defense-grade encryption meets ultra-efficient communication. Built for environments where every byte matters and every message must be protected.
Post-quantum,from day one.
AUDITED CODEBASE FROM SIGNAL FOUNDATION
Signal Foundation audited cryptographic stack
Ultra-Low Bandwidth Communication
Arc uses Opus codec at 16kbps — the same approach as WhatsApp — to deliver voice messages at 1/8th the size of traditional AAC encoding. Combined with WebP image compression (30% reduction) and Proto3 binary serialization, Arc operates reliably on 3G networks and satellite connections.
Voice Message Compression
File size per minute of voice recording
8x smaller
| Network | Speed | Voice (1 min) | Photo (500KB) |
|---|---|---|---|
| 5G | 100 Mbps+ | <1s | <1s |
| 4G LTE | 10 Mbps | <1s | <1s |
| 3G | 1 Mbps | <1s | ~4s |
| 2G / EDGE | 50 kbps | ~20s | ~80s |
| Satellite (LEO) | 25 Mbps | <1s | <1s |
| BLE Mesh | 1 Mbps | <1s | ~4s |
5-Phase E2EE Pipeline
Every message passes through five cryptographic phases before reaching the recipient. Each phase addresses a distinct threat vector, providing defense-in-depth that no single algorithm can achieve alone.
PQXDH
Post-quantum key exchange with ML-KEM-1024 hybrid
Double Ratchet
Forward secrecy — unique key per message, immediate deletion
AES-256-GCM
Authenticated encryption with 256-bit keys
AEGIS
Per-message XEdDSA digital signatures (via libsignal) (Arc original)
Sealed Sender
Sender identity hidden from server infrastructure
Post-Quantum Cryptography
ML-KEM-1024
Hybrid Design
Arc combines classical and post-quantum cryptography. Even if one algorithm is broken, the other maintains security. This dual-defense protects against both today's threats and tomorrow's quantum computers.
⚠️ Protects against "Harvest Now, Decrypt Later" attacks — adversaries who record encrypted traffic today to decrypt with future quantum computers.
AEGIS (Arc Enhanced Guard & Integrity System) ARC ORIGINAL
AEGIS (Arc Enhanced Guard & Integrity System) attaches a cryptographic XEdDSA signature (via libsignal) to every single message. Neither Signal nor WhatsApp offer per-message digital signatures. AEGIS provides legally admissible proof of message origin, tamper detection, and non-repudiation.
XEdDSA.Sign(senderId || timestamp || content)
// 64-byte Ed25519 signature
Authentication
Cryptographic proof of sender identity
Tamper Detection
Any modification detected instantly
Non-Repudiation
Sender cannot deny message origin
BLE Mesh Network ARC ORIGINAL
Offline E2EE
Full end-to-end encryption over Bluetooth Low Energy. No internet, no cell towers, no servers. The only major messenger with offline encrypted communication.
Ephemeral Zones
Automatically create temporary communication zones during disasters. Map evacuation points, medical stations, and resource distribution centers in real-time.
Zero-Knowledge Presence
Prove you're nearby without revealing your exact location. Privacy-preserving proximity verification for trust establishment.
IGF (Instant Gone Forever)
Time-limited messages with cryptographically guaranteed deletion. Even on the free Essential plan, users can configure expiry from 1 minute to 52 weeks. Device-level deletion is instant regardless of plan.
On-Device AI
AI runs entirely on your device. Zero server communication. Your conversations never leave your phone — not even for AI processing.
How Arc Compares
Independent review comparing Arc V2 against 16 competitors (Signal, iMessage, WhatsApp, Telegram, LINE, Threema, Wire, Element, Session, Viber, XChat, KakaoTalk, Slack, Discord, Chatwork, Google Messages) using an 8-axis 100-point rubric.
Use Cases
Healthcare
Patient data communication must comply with HIPAA and privacy regulations while remaining fast enough for clinical workflows.
- ✓E2EE + PQC protects patient data against current and future threats
- ✓IGF configurable auto-deletion (1 min to 52 weeks) for sensitive clinical discussions
- ✓AEGIS signatures provide legal audit trail for clinical decisions
- ✓Opus 16kbps enables voice messages in poor-reception hospital zones
Disaster Response
Communication infrastructure is destroyed. Rescue teams need secure coordination without cell towers or internet.
- ✓BLE Mesh creates ad-hoc networks without infrastructure
- ✓Ephemeral Zones map evacuation and medical aid points
- ✓120KB/min voice — usable on survival-grade bandwidth
Field Operations
Remote sites with no connectivity need data collection, team coordination, and secure communication with headquarters.
- ✓Offline-first design: record locally, auto-sync on reconnect
- ✓BLE Mesh for team communication across large sites
- ✓Environmental sensors, quality tracking, and time management
Standards & Compliance
🇺🇸NIST CSF 2.0
Cybersecurity framework for critical infrastructure
🇺🇸NIST SP 800-53
Security and privacy controls for federal systems
🇺🇸FIPS 140-3
Cryptographic module validation (pending)
🇺🇸FIPS 203 (ML-KEM)
ML-KEM post-quantum key encapsulation standard
🌐ISO/IEC 27001
International information security management
🇪🇺GDPR
EU data protection and privacy regulation
🇬🇧UK Cyber Essentials+
UK government-backed cyber security certification
🇺🇸HIPAA
Design-ready for healthcare data protection
Read the Full Security Whitepaper
Dive deeper into Arc's cryptographic design, threat model analysis, and compliance documentation.