OAuth 2.0 has limitationsJWT needs improvement

QAuth: Authentication
Rebuilt for the Quantum Era

Post-quantum dual signatures. Encrypted payloads. Mandatory proof-of-possession. Built-in revocation. The OAuth 2.0 and JWT replacement you've been waiting for.
Ed25519 + ML-DSA-65NIST FIPS 204Open SourceMulti-language SDKs

The Problem

OAuth 2.0 and JWT have fundamental, unfixable security flaws that have caused countless breaches.

JWT Vulnerabilities

  • xAlgorithm confusion - Attacker chooses verification method
  • x"None" algorithm - Complete signature bypass
  • xKey ID injection - SQL injection, path traversal via kid
  • xExposed payload - Base64 claims visible to everyone
  • xNo revocation - Tokens valid until expiry

OAuth 2.0 Vulnerabilities

  • xRedirect URI manipulation - Token interception
  • xAuthorization code interception - Full account takeover
  • xBearer token model - Stolen token = full access
  • xPKCE downgrade - Protection can be bypassed
  • xScope explosion - Unmaintainable permission strings

Security Comparison

QAuth mitigates every known attack vector in OAuth 2.0 and JWT.

Algorithm Confusion

JWT

Vulnerable

OAuth

N/A

QAuth

Impossible

No algorithm field in QAuth

"None" Algorithm

JWT

Vulnerable

OAuth

N/A

QAuth

Impossible

Algorithm not configurable

Bearer Token Theft

JWT

Vulnerable

OAuth

Vulnerable

QAuth

Protected

Proof of possession required

Redirect URI Attack

JWT

N/A

OAuth

Vulnerable

QAuth

Protected

Cryptographic binding

Token Replay

JWT

Vulnerable

OAuth

Vulnerable

QAuth

Protected

Request-specific proofs

Payload Inspection

JWT

Exposed

OAuth

N/A

QAuth

Encrypted

XChaCha20-Poly1305 encryption

Post-Quantum Attack

JWT

Future Risk

OAuth

Future Risk

QAuth

Protected

ML-DSA-65 signatures

Revocation Delay

JWT

Hours/Days

OAuth

Hours

QAuth

5 Minutes

Built-in revocation system

Defense-in-Depth Features

Every QAuth feature is designed to eliminate an entire class of attacks.

3373 bytes

Dual Signatures

Ed25519 + ML-DSA-65

Classical Ed25519 combined with post-quantum ML-DSA-65. Both must verify. If quantum computers break Ed25519, ML-DSA-65 remains secure.

Private

Encrypted Payloads

XChaCha20-Poly1305

Unlike JWT's base64-encoded claims visible to everyone, QAuth encrypts all payload data. Your claims are private, not just signed.

Required

Proof of Possession

Mandatory, Not Optional

Every request must prove key ownership. Stolen tokens are useless without the private key. No more bearer token theft attacks.

Instant

Built-in Revocation

5-Minute Window

Instant token invalidation with 5-minute worst-case propagation. No more waiting for JWT expiry after a breach.

Scalable

Policy References

No Scope Explosion

Replace OAuth's scope strings with policy document references. Fine-grained RBAC/ABAC/ReBAC without bloated tokens.

Secure

Server-Enforced Crypto

No Algorithm Confusion

Server enforces all cryptographic parameters. No client-controlled algorithm selection. Eliminates entire attack classes.

Multi-Language SDKs

Use QAuth in your preferred language. Same API, same security guarantees.

use qauth::{Issuer, Token, Validator, Policy, PolicyEngine};

// Generate issuer with dual keys (Ed25519 + ML-DSA-65)
let issuer = Issuer::generate()?;

// Create a QToken with encrypted payload
let token = Token::builder()
    .subject("user-12345")
    .audience("https://api.example.com")
    .policy_ref("urn:qauth:policy:standard")
    .expires_in(Duration::from_secs(3600))
    .build(&issuer)?;

// Validate with dual signature verification
let validator = Validator::new(issuer.verifying_keys());
let claims = validator.validate(&token)?;

// Policy-based authorization
let engine = PolicyEngine::new();
let result = engine.evaluate(&policy, &context);

Why QAuth?

Built from the ground up for the post-quantum era.

Key Features

  • Complete specification with RFC-style documentation
  • Working reference implementation in Rust with 36+ tests
  • Real post-quantum cryptography using ML-DSA-65 (Dilithium3)
  • Multi-language SDKs with consistent APIs
  • Open source under MIT license

Developer Resources

Everything you need to integrate QAuth into your application.

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Part of QuantumShield

QAuth is built on top of QuantumShield's post-quantum cryptography primitives. Hybrid KEM, dual signatures, and cascading encryption—all working together.