Aexa Web Vault

New here? Start with : it creates your private key file and the public key file you give to others.

Encryption and decryption happen locally in your browser. Your file never leaves your device.

Files, keys and identities are the same across the Web Vault and the native macOS and Windows applications: a file protected in one unlocks in the others.

Generate Identity

Your identity is generated on this device. Aexa never receives it. You will download two files: a private key file you keep, and a public key file you can send to anyone who needs to protect a file for you.

Cryptographic profile Standard: ML-KEM-768 + AES-256-GCM. NIST FIPS 203 security category 3. The default; suitable for everyday use. High Assurance Cryptographic Profile: ML-KEM-1024 + AES-256-GCM. NIST FIPS 203 security category 5: the higher-security parameter set of the same standard, with slightly larger files.

“High Assurance” names the cryptographic profile only. It says nothing about the browser’s isolation, which is the same for both profiles.

Entropy pool (optional)

An entropy pool is a file of random numbers made ahead of time on a quantum computer. It is optional. If you choose one, this identity is made from two ingredients: fresh random numbers from this device, and one piece of the pool. Each piece is used once and then removed from the pool file.

How is a pool made, and what does it add?

1. A quantum computer flips the coins. Each of its qubits is put into a state that is equally likely to be read as 0 or as 1, and then it is read. Which way each one falls is not worked out by a formula, so it cannot be calculated ahead of time.

2. Aexa checks the results. The raw readings are tested. A run that fails is thrown away. What passes is condensed into 64-byte pieces called segments, and the pool file records which machine and which job produced them.

3. Your device mixes one piece in. When you generate a key, this page combines one segment with your device’s own random numbers. The result is at least as unpredictable as your device’s numbers alone, even if someone else had a copy of the pool.

What it adds. A second source of randomness that does not depend on this device, and a receipt naming the machine, the job and the segment used.

What it does not do. It does not change how your files are encrypted. It is not a certified or government-validated randomness source. Whoever made the pool could have kept a copy, which is why your device’s own generator, not the pool, is what protects your key. The machine and job named in the receipt are copied from the pool file and are not signed.

Passphrase for your private key file

If you forget this passphrase, your key cannot be recovered, not by you and not by Aexa. Every file protected for this key becomes permanently unreadable. There is no reset.

I understand that a lost passphrase cannot be recovered.

What just happened?

AES-256

Protects the actual contents of the file.

ML-KEM-768 and ML-KEM-1024

The NIST-standardized lattice-based post-quantum key-establishment mechanism (FIPS 203) used to protect the file encryption key. It is designed to resist attacks from both classical and future quantum computers. ML-KEM-768 is security category 3 and is the Standard profile; ML-KEM-1024 is security category 5 and is the High Assurance profile. They are two parameter sets of the same standard: the High Assurance Cryptographic Profile is the higher-security parameter set, not a different kind of protection.

Your key file

The .aexkey file this Web Vault writes is the same version 2 format the native macOS and Windows applications write: the whole header is authenticated, and the key inside is protected with a passphrase using Argon2id at one fixed, approved cost. Older version 1 key files from the earlier browser build still unlock here; they cannot be created any more.

Local encryption

The file is processed in your browser. Aexa does not receive the plaintext file. This page is served with a Content-Security-Policy that denies every fetch, socket and resource channel after it has loaded, and the application removes WebRTC, the one channel no browser's policy can deny, from itself. Encryption and decryption keep working with your network disconnected. You can try it.

What the Web Vault does not do

It does not tell you who sent a file. A protected file proves only that someone who had your public key created it. It does not have the native applications’ isolation property: a browser tab cannot refuse to be a network application, whereas the sandboxed native process cannot reach the network at all. Nothing here is a FIPS 140-3 validated module, and nothing here is approved for classified, CUI, NSS or regulated data.

Post-Quantum Vault

Generate Identity

Your identity is ready

Protect a file

1 Recipient key

2 File

3 Protect

Your protected file is ready.

Unlock a file

1 Protected file

2 Your private key

3 Unlock

Original file ready.

AES-256

ML-KEM-768 and ML-KEM-1024

Your key file

Local encryption

What the Web Vault does not do