About PQCServer
Privacy-first.
Quantum-ready.
Zero-knowledge.
PQCServer is a free, open-architecture service for post-quantum encrypted messaging,
file storage, and document notarization. It was built to make NIST 2024 post-quantum
cryptography accessible to everyone — not just developers and researchers.
The service is part of a privacy ecosystem that includes
onionmail.org (anonymous email),
oniondrive.org (anonymous file storage),
pqctoolkit.com (standalone PQC toolkit),
and postquantum.tools (educational hub).
Zero-Knowledge Architecture
The term "zero-knowledge" is often used loosely in the security industry.
On PQCServer it has a precise technical meaning:
the server is cryptographically incapable of reading your data.
This is not a policy choice or a promise — it is a mathematical property of the system.
All cryptographic operations happen exclusively in your browser using the
Web Crypto API and the pqc JavaScript library.
Your private keys never leave your device. The server receives only ciphertext.
Browser (your device) PQCServer Recipient browser
─────────────────── ───────── ─────────────────
ML-KEM keygen() │ │
publicKey → saved to server ─────────►│ MongoDB: users │
secretKey → stays here only │ │
│ │
ML-KEM.encapsulate(recipientPubKey) │ │
sharedSecret │ │
cipherText ──────────────────────────►│ │
AES-256-GCM.encrypt(sharedSecret, msg) │ │
ciphertext ──────────────────────────►│ MongoDB: messages │
◄── shortlink ────────────────────────│ │
│ │
│◄── GET /m/:id ───────────│
│─── ciphertext ──────────►│
│ │
│ ML-KEM.decapsulate(cipherText, secretKey)
│ │ → sharedSecret
│ │ → plaintext
│ │
Server knowledge: ciphertext only. Plaintext: never.
Cryptographic Algorithms
PQCServer uses exclusively algorithms standardized by
NIST
in August 2024 after a 7-year global competition involving hundreds of submissions
from academic and industry researchers worldwide.
NIST FIPS-203 · 2024
ML-KEM
Module Lattice-Based Key Encapsulation Mechanism
(formerly CRYSTALS-Kyber)
Used for: encryption
Replaces: RSA, ECDH
Security: 128/192/256-bit
Math: Module-LWE problem
NIST FIPS-204 · 2024
ML-DSA
Module Lattice-Based Digital Signature Algorithm
(formerly CRYSTALS-Dilithium)
Used for: signatures
Replaces: RSA sign, ECDSA
Security: 128/192/256-bit
Math: Module-LWE problem
Standard · RFC
AES-256-GCM
Advanced Encryption Standard
Galois/Counter Mode
Used for: symmetric encryption
Key source: ML-KEM shared secret
Security: 256-bit
Quantum-safe: ✓ already
The hybrid scheme combines ML-KEM (for quantum-safe key exchange) with AES-256-GCM
(for symmetric encryption of the actual data). This is the same pattern recommended by
NIST, used by Google, Cloudflare, and AWS in their own post-quantum migrations.
AES-256 is already quantum-safe — Grover's algorithm only halves its effective key length,
which 256-bit keys comfortably absorb.
Design Principles
- Server-side zero-knowledge by construction. Not a policy. The server architecture makes it mathematically impossible to access plaintext.
- No installation required. Everything runs in the browser. No plugins, extensions or apps. Any modern browser on any device works.
- NIST 2024 standards only. No custom or unreviewed algorithms. Every cryptographic primitive used has been through years of public scrutiny.
- No tracking, no analytics, no cookies. We collect the minimum data required to provide the service. We do not sell or share any data.
- Free forever. Encryption is a right, not a premium feature. The full service is free with no artificial limits.
- Embeddable by design. The widget architecture allows any website to add post-quantum encryption with one line of code.
- Open architecture. The cryptographic approach is fully documented and auditable. The server-side code handles only ciphertext.
The Privacy Ecosystem
PQCServer is part of a broader set of privacy tools designed to work together:
Anonymous email service. Integrates PQCServer widget for post-quantum encrypted message attachments.
Anonymous file storage. Complementary to PQCServer vault — anonymous storage vs quantum-safe encrypted storage.
Standalone browser-based PQC toolkit. Generate keys, encrypt, sign and verify — without any server involvement.
Educational hub explaining post-quantum cryptography, the quantum threat timeline, and NIST 2024 standards.
Standards & References
NIST FIPS-203 — ML-KEM standard (August 2024)
NIST FIPS-204 — ML-DSA standard (August 2024)
NIST FIPS-205 — SLH-DSA standard (August 2024)
Open Quantum Safe Project — open source PQC implementations
Cloudflare — State of post-quantum internet 2025
AWS Post-Quantum Cryptography