Encrypt files for specific recipients using ML-KEM-768, sign with ML-DSA-65, and package them into a portable container. Everything runs in your browser.
CEF (COSE Encrypted Files) is a secure file exchange format. It packages files into a ZIP container where the manifest and each file are individually encrypted with AES-256-GCM. Keys are wrapped using ML-KEM-768 (post-quantum), and the manifest is signed with ML-DSA-65. Without a recipient's private key, file names, types, and metadata are inaccessible.
| Exposed | Protected | |
|---|---|---|
| Files | Count, approx. sizes | Names, types, content |
| Sender | Signing key ID | Name, email |
| Recipients | Key IDs, wrap algorithm | Names, emails, identities |
| Crypto | AES-256-GCM, ML-KEM-768 | Keys, plaintext |
| Timestamp | TSA, time, policy | (public by design) |
The sender signs the container with ML-DSA-65 (FIPS 204). Recipients verify this signature to confirm the container hasn't been tampered with.
Files are encrypted with AES-256-GCM. Each recipient gets a separate key wrap using ML-KEM-768. File names are randomized — originals are in the encrypted manifest.
Drop files or browse
The selected recipient's ML-KEM-768 key unwraps the content encryption key. The sender's ML-DSA-65 signature is verified. File hashes are checked.
Drop a .cef container to open