Your vault, decryptable with or without us.Keep the archive. Keep the keys.

Every vault export is an OAIS-style bundle composed of three parts: a manifest.json describing the file tree, one ciphertext blob per file, and a printable crypto-spec PDF listing every algorithm and parameter we use. There is no proprietary container, no closed binary format, and no Henedo-specific decoder.

Journal entries and the 1,000-prompt Life Story export as plain UTF-8 markdown bundles, one file per entry or answer. Voice and video answers export as standard WebM/Opus or MP4/AAC and MP4/H.264, opaquely the same files your browser recorded, decryptable with the same FEK-under-MK procedure as everything else in the vault. No special viewer required.

With your passphrase, your device-bound Account Secret Key (ASK), and the export bundle, you (or your heirs) can decrypt the entire vault on any modern computer running standard cryptographic libraries. We test this end-to-end every build.

Keep these instructions with your complete export, and store its keys securely. The exact parameters live in the crypto-spec PDF inside the bundle, and the full encryption architecture (AES-256-GCM, Argon2id, post-quantum signatures) is documented page-by-page on the security page, but the algorithm shape is public:

1. KEK = Argon2id(passphrase + ASK_hex, salt, t=3, p=4)
       → HKDF-SHA-256('henedo-kek-v<N>', 32 bytes)

   The Argon2id memory cost and HKDF label depend on your account's
   KDF version (current default v3 = 128 MiB); the crypto-spec.txt
   inside your export bundle states the exact parameters for YOUR
   account. Alternatively, your Recovery Key derives the unwrap key
   with no Argon2id at all, that path is version-independent.

2. MK  = AES-256-GCM.decrypt(KEK, EMK, mk_iv)

3. For each encrypted file in the manifest:
     FEK  = AES-256-GCM.decrypt(MK, EFEK, fek_iv)
     plaintext = AES-256-GCM.decrypt(FEK, ciphertext, file_iv)

4. Verify the file_name is decrypted with MK using the encrypted_file_name + file_name_iv columns.

The only library dependencies are AES-256-GCM, Argon2id, and HKDF-SHA-256.
All three have reference implementations in @noble/* and Web Crypto.

Proving a file is genuinely yours is portable too. Anything your family opens from an Eternal Vault can be saved alongside a small .proof file carrying that document's fingerprint, its place in the vault's signed Merkle tree, the seal date, and all three signatures (Ed25519, ML-DSA-65 and SLH-DSA) with the algorithms named in plain text. A grandchild in eighty years can check that one file on its own — without the rest of the vault, and without us.

We ship a single-file, dependency-free HTML page that implements the recipe above end-to-end. It runs entirely offline: open it in any modern browser, pick your export zip, enter your passphrase and Account Secret Key, and your vault unlocks on your local machine. No Henedo server, code, or domain is contacted.

The same file is automatically embedded inside every export bundle, so heirs always have an offline copy alongside the data. You can also keep an extra copy alongside the complete encrypted export on storage you control.

Inspect the file, audit the embedded crypto, save it offline. Web Crypto API + Argon2id are inlined; nothing else is required.

Eternal Vault is $699 once for 100 GiB with a 100-year preservation term. Payment creates an archive purchase in your account. Open Eternal Vault in the dashboard, upload files, choose inheritors and seal an encrypted snapshot. The current storage backend is Cloudflare R2.

The seal binds the archive manifest and integrity proofs. Current purchases use complete inheritor keys prepared for email delivery. Save the keys securely so you can share them if an email does not arrive. A membership is not required to purchase an Eternal archive.

The current cloud purchase does not include M-Disc delivery or an invested preservation fund. Older purchases that include physical delivery retain their contracted scope. Check the order and fulfillment status of those purchases in your account; a sealed cloud archive is not evidence that a disc has shipped.

An offline copy must contain the complete encrypted archive, its format documentation and the corresponding full key. A partial disc or a key by itself cannot reconstruct missing files.

Independent recovery depends on what you and your inheritors already hold:

• Archive: retain every encrypted file and the manifest from the complete export.
• Keys: keep the full decryption material securely, separately from the archive copy.
• Reader: save the offline reader and format documentation alongside the data.

Cloud access requires an operating service. A purchased preservation term does not prove that a century of operations, a separate custodian or a recurring hardware-refresh program is already in place.

From your Settings page you can:

• Export your full vault as the OAIS bundle described above. No fee, no review queue, no rate limits beyond what is needed to keep the system stable.
• Delete your account and all associated ciphertexts under GDPR Article 17 right-to-erasure. We confirm by email, then irreversibly destroy the data on our side. See the privacy policy for the exact retention schedule.
• Keep an independent copy of the complete export and its offline reader, with the required keys stored securely. Physical-delivery terms apply only to older purchases that include them.

We do not gate exports behind tier upgrades. We do not charge per-MB egress. Customer confidence costs us less than customer churn.

The Living Vault and hosted Eternal access require the service to operate. A complete independent archive copy and its keys let you recover the content with the documented format and standard tools, without relying on the hosted access page.