Attestation User Guide
How to sign up, upload and share documents in Memora's attestation app, what the safety numbers and recovery code are for, and how versions and workspaces work.
Memora's attestation app lets you prove that a document existed, in exactly this form, at a point in time, and share that proof with people you choose. The app encrypts the document in your browser before it leaves your machine. We store ciphertext and proofs, never your unencrypted content or a key that can decrypt it.
Sign up with a passkey
A passkey secures your account: Touch ID, Face ID, Windows Hello, or a hardware security key. When you sign up you enroll a passkey and receive a one-time recovery code.
Keep the recovery code somewhere safe. Your documents are encrypted with keys that only your passkey and your recovery code can unlock. We hold no copy that can decrypt them. If you lose every enrolled device and the recovery code, your documents cannot be recovered by anyone, including us. Print the code or store it in a password manager.
Signing in is passkey-first: one passkey prompt both signs you in and unlocks your documents. A password fallback exists for sign-in, but it cannot unlock your documents on a new device without a passkey or the recovery code.
Under Settings, Security and passkeys you can add a passkey on another device, remove a lost device, and view your recovery status.
Upload a document
- Choose Upload and select a file.
- Add a name and the custom metadata fields you want recorded, such as a counterparty, a contract reference or a date. For each field you can choose who may see it.
- Choose who may view the document.
- Confirm.
In your browser, before anything is sent, the app computes the document's SHA-256 hash and encrypts the file with a key created for that document. Only the encrypted file and the hash leave your machine. The hash and the metadata you marked as on-chain are anchored on the Canton Network, where they can be disclosed selectively to the parties you named. The encrypted file is stored off-chain, and its integrity is checked against the ledger whenever it is read.
The status chip on the document shows the anchoring state, from pending through to anchored.
Verify a document
Open a document and choose Verify. Select a file from your machine. The app hashes it locally and compares the hash to the one anchored on Canton. A match means the file is byte for byte the document that was attested. A mismatch means it has changed, even by a single character.
You can also read the anchored hash from the document's detail page and compare it against any independent SHA-256 tool.
Share by email
From a document's detail page, Share to a recipient's email address. Sharing re-wraps the document's key to the recipient's public key, so only they can unwrap it. We never hold a key that can decrypt the content.
Only the owner can share or revoke. Revoking removes the recipient's access to the key.
Safety numbers
Because we serve the public keys used for sharing, a compromised server could try to substitute its own key. To detect this, the app remembers each contact's key the first time you share with them, and shows a safety number, a short fingerprint of that key. To be certain you are sharing with the right person, compare safety numbers over another channel, such as a phone call.
If a contact's key changes, the app shows a blocking key changed warning and will not share until you confirm the change is expected.
Versions
Documents are never edited in place. Publishing a new version creates a successor that carries the same viewers forward, increments the version number, and marks the previous version as superseded. Each version keeps its own anchored hash. The detail page shows the full history with a thumbnail and sortable columns, so you can prove what each version contained and when.
Workspaces
A workspace is a shared space for an organization. Members have one of three roles:
| Role | Can |
|---|---|
| Admin | Everything a member can, plus invite and remove members, change roles, rename the workspace, and configure recovery. |
| Member | Upload, view documents shared with them, share their own documents. |
| Guest | View specific documents shared with them. |
You can belong to several workspaces and switch between them from the left rail.
Workspace recovery
An admin can turn on recovery for a workspace so that a member who loses every device and their recovery code does not lose the workspace's documents. When recovery is enabled, the app generates a recovery key pair in the admin's browser and seals its private half to that admin's own passkey. We never hold it. Documents uploaded after recovery is enabled also wrap their key to the workspace recovery key, so the custodian admin can later recover, decrypt and download them in their own browser.
The app shows two current limits: recovery covers documents uploaded after it was enabled, not earlier ones, and there is a single custodian with no key rotation.
DocuSign provenance
Documents that arrive from a connected DocuSign account carry a gold DocuSign badge on their thumbnail and a DocuSign chip in the Source column, so signed agreements are distinguishable from manual uploads at a glance. See DocuSign Integration.
Custom metadata and disclosure
You can mark each custom field you add for on-chain anchoring or keep it off-chain, and make each on-chain field visible to specific parties. This maps directly onto Canton's selective-disclosure model: a party you name sees only the fields you disclosed to them. Fields kept off-chain are stored encrypted with the document.
History
The History view is a log of every document event in the workspace: uploads, versions, shares and revocations, with who did what and when.
Getting help
For account, billing or workspace questions, use the support contact in the app. We will never ask for your recovery code or your passkey.