Multi-Layer E2EE Architecture
A commercial security product with a published engineering direction
Arc core specification
Arc's core specification is ML-KEM-1024/PQXDH, E2EE, Sender Keys, Sealed Sender, IGF, and offline Mesh. This Security page documents the scope and technical details.
PQXDH Key Exchange
A commercial security product with a published engineering direction
Double Ratchet
A commercial security product with a published engineering direction
AES-256-GCM Encryption
A commercial security product with a published engineering direction
XEdDSA Signatures (libsignal)
A commercial security product with a published engineering direction
Client-Side Sealed Sender
A commercial security product with a published engineering direction
Comparison with 20 Major Messengers
Each primary source supports only the category where it is cited; it does not substantiate every claim or score and does not imply vendor endorsement.
ML-KEM-1024 Parameters
NIST FIPS 203 standardized post-quantum Key Encapsulation Mechanism.
| Algorithm | ML-KEM-1024 (via libsignal-client) |
| NIST Security Level | Security category 5 |
| Classical Security | 2^128 bit (X25519) |
| Quantum Security | NIST security category 5 |
| Foundation | Module Lattice (FIPS 203) |
| Public Key Size | 1,184 bytes |
| Secret Key Size | 2,400 bytes |
| Ciphertext Size | 1,088 bytes |
Compliance & Standards
🇺🇸NIST CSF 2.0
NIST framework. 6 functions for systematic cyber risk management.
🇺🇸NIST SP 800-53
Federal security controls. FedRAMP foundation.
🇺🇸FIPS 140-3
A commercial security product with a published engineering direction
🇺🇸NIST SP 800-175B
Cryptographic algorithm selection guide. Based on FIPS 203.
🌐ISO/IEC 27001
International ISMS certification. B2B/B2G trust foundation.
🇪🇺GDPR
EU General Data Protection Regulation. World's highest protection standard.
🇬🇧UK Cyber Essentials+
UK government-certified cybersecurity certification.
🇬🇧NCSC Cloud Security
UK NCSC 14 Principles. Cloud security assessment standard.
Designed with reference to published guidance from US NIST, EU GDPR, UK NCSC, and ISO. This is not a certification or a third-party audit.
System Architecture Documentation
A commercial security product with a published engineering direction
15+ Technical Sections
Layer architecture, PQC implementation, encryption pipeline, data storage, and more
Bilingual (EN/JP)
Full documentation available in English and Japanese with one-click toggle
Version 3.1 — March 2026
A commercial security product with a published engineering direction
This document is classified as confidential and available exclusively to NDA-bound partners, investors, and authorized technical reviewers. Access requires prior approval by Atlas Associates.