Post‑Quantum Security Guide

How to share secrets securely with NoTrust.now

Quick Start

  1. Set Up Your Key Vault

    The first time, choose a vault password. Your ML‑KEM‑768 and ML‑DSA‑65 key pairs are generated in your browser and kept there, encrypted.

  2. Choose the Recipient

    Pick a contact whose public key you have added, or yourself. The secret is sealed to that key and no other key opens it.

  3. Enter Your Secret and a Passphrase

    Paste your password, API key, or sensitive data and set a passphrase (min 6 chars). Neither leaves your browser unencrypted.

  4. Configure & Share

    Set expiration time and max views. Share the token and the passphrase through different channels.

How Each Secret Is Sealed

There is one mode. Opening a secret takes two things: its passphrase and the recipient's private key.

Quantum Mode

Quantum-Resistant
  1. ML‑KEM‑768 (Kyber) encapsulates a fresh shared secret to the recipient's public key. Only their private key can recover it.
  2. scrypt turns your passphrase into a second 256‑bit key, and the two are combined into the encryption key.
  3. ChaCha20‑Poly1305 encrypts the secret and detects any change to it.
  4. If you choose to sign, ML‑DSA‑65 (Dilithium) signs the result with your private key, so the recipient can check who sent it.
  5. The server keeps the ciphertext and the public keys, never the passphrase or a private key, and destroys the secret after reading or on expiry.

What is Post‑Quantum Cryptography?

Post‑quantum cryptography (PQC) refers to cryptographic algorithms designed to be secure against attacks from both classical and quantum computers. Traditional encryption methods like RSA and ECC could be broken by sufficiently powerful quantum computers.

Why It Matters

NIST has standardized post‑quantum algorithms (ML-KEM and ML-DSA) to protect against "harvest now, decrypt later" attacks, where adversaries collect encrypted data today to decrypt it once quantum computers become available.

ML‑KEM‑768 (Kyber)
Key encapsulation mechanism for secure key exchange resistant to quantum attacks
ML‑DSA‑65 (Dilithium)
Digital signature algorithm providing quantum-resistant authentication

Frequently Asked Questions

Why do I need a key vault?
Every secret is sealed to a recipient's ML‑KEM‑768 public key, and opening it takes the matching private key. The vault keeps your key pairs and your contacts' public keys in this browser, encrypted with your vault password. It is not an account: its contents never reach our server.
Can I send a secret to someone who has no vault?
No. A secret is sealed to the recipient's public key, so they need a vault first. Ask them to set one up and send you their public key, then add it to your contacts. You can always seal a secret to yourself.
Can you see my secrets?
No. Your secrets are encrypted in your browser before being sent to our server. We only store encrypted data and never receive your passphrases or private keys.
What happens after a secret is viewed?
Secrets are automatically deleted from our servers after being viewed once (or reaching max views) or when they expire—whichever comes first. They cannot be recovered.
Do quantum computers break AES‑256?
No. The best known quantum attack on symmetric ciphers (Grover's algorithm) at most halves the effective key length, and a 256‑bit key keeps a wide margin. The quantum threat is to public‑key exchange, such as RSA and elliptic curves. NoTrust.now uses ML‑KEM‑768 for that step and ChaCha20‑Poly1305 with a 256‑bit key for the content.
Is there a size limit?
Text secrets can be up to 3000 characters. For files use PQC File Encryption (up to 2 MB); for more data, split it into several secrets or use the API.

Start Sharing Secrets Securely

Set up your key vault and seal your first secret.

Create a SecretOpen Your Vault