Encrypt a file with post-quantum cryptography
ML-KEM-1024 + XChaCha20-Poly1305, running in your browser with the real open-source ShieldFive crypto core. Nothing is uploaded.
Drop a file, or click to choose
Any file, up to 50.0 MB · encrypted in your browser
Encryption and decryption run entirely in your browser using the real @shieldfive/crypto library — the same open-source, post-quantum core that encrypts files in the app. Nothing is uploaded or stored.
Managing keys by hand is fine for a one-off. ShieldFive does all of this for you — post-quantum encryption on your device, keys you control, files synced and shareable — with nothing left in plaintext on our servers.
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- Is this actually post-quantum?
- Yes. It uses the same open-source @shieldfive/crypto library that encrypts files in the app: a hybrid of ML-KEM-1024 (NIST FIPS 203, security level 5) and XChaCha20-Poly1305. An attacker would have to break both the post-quantum KEM and the classical cipher to recover your file.
- Are my files uploaded?
- No. Encryption and decryption happen entirely in your browser. The file, the keys, and the plaintext never leave your device and are never sent to ShieldFive. You can turn off your network and it still works.
- What is the recovery key, and why must I keep it?
- When you encrypt, a fresh keypair is generated in your browser. The recovery key contains the secret needed to decrypt. Because nothing is stored on our side, that key is the only way back to your file — if you lose it, the file cannot be decrypted by anyone, including us.
- Why would I encrypt a file this way?
- To protect a file against "harvest now, decrypt later" — an adversary copying encrypted data today to decrypt once quantum computers mature. Post-quantum encryption at rest closes that window for files with a long confidentiality life, such as legal, medical, or financial records.