Technology
Defense-grade encryption meets ultra-efficient communication. Built for environments where every byte matters and every message must be protected.
Ultra-Low Bandwidth Communication
Arc uses Opus codec at 16kbps β the same approach as WhatsApp β to deliver voice messages at 1/8th the size of traditional AAC encoding. Combined with WebP image compression (90% 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 β unique key per message, immediate deletion
AES-256-GCM
Authenticated encryption with 256-bit keys
AEGIS
Per-message Ed25519 digital signatures (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.
β οΈ Protects against "Harvest Now, Decrypt Later" attacks β 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 Ed25519 signature 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 β not even for AI processing.
How Arc Compares
| Signal | Arc | ||
|---|---|---|---|
| Post-Quantum Crypto | Partial (PQXDH) | PQXDH | PQXDH ML-KEM-1024 |
| Per-Message Signature | --- | --- | AEGIS (XEdDSA) |
| Sealed Sender | Server-side | --- | Client-side |
| Offline Mesh E2EE | --- | --- | BLE Multi-hop E2EE |
| Voice Codec | Opus 24kbps | Opus 16kbps | Opus 16kbps |
| Message Expiry | Basic | Basic | Advanced (3-tier) |
| On-Device AI | --- | --- | Gemma 3n (4B) |
| E2EE Free for All | β | β | β |
Use Cases
Healthcare
Patient data communication must comply with HIPAA and privacy regulations while remaining fast enough for clinical workflows.
- βE2EE + PQC protects patient data against current and future threats
- βIGF configurable auto-deletion (1 min to 52 weeks) for sensitive clinical discussions
- βAEGIS signatures provide legal audit trail for clinical decisions
- βOpus 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.
- βBLE Mesh creates ad-hoc networks without infrastructure
- βEphemeral Zones map evacuation and medical aid points
- β120KB/min voice β usable on survival-grade bandwidth
- βDisaster coupon: time-limited free access for all users worldwide
Field Operations
Remote sites with no connectivity need data collection, team coordination, and secure communication with headquarters.
- βOffline-first design: record locally, auto-sync on reconnect
- βBLE Mesh for team communication across large sites
- βEnvironmental sensors, quality tracking, and time management
Standards & Compliance
πΊπΈNIST CSF 2.0
Cybersecurity framework for critical infrastructure
πΊπΈNIST SP 800-53
Security and privacy controls for federal systems
πΊπΈFIPS 140-3
Cryptographic module validation (pending)
πΊπΈFIPS 203 (ML-KEM)
ML-KEM post-quantum key encapsulation standard
πISO/IEC 27001
International information security management
πͺπΊGDPR
EU data protection and privacy regulation
π¬π§UK Cyber Essentials+
UK government-backed cyber security certification
πΊπΈHIPAA
Design-ready for healthcare data protection
Read the Full Security Whitepaper
Dive deeper into Arc's cryptographic design, threat model analysis, and compliance documentation.