A signature, a file match and a timestamp answer different questions. Here is what each one tells you, how your documents are protected, and what lets you ask of us.
Document security and privacy, from the file to your account.
The file is the evidence, not the badge.
01 / Results
A check result has three lines. Read each one.
File comparison tells you whether the bytes match. Record source tells you what they match: an account seal, a public-tool stamp, or nothing. Timestamp tells you the anchor state. A kdid lookup without a file shows the record, not a comparison of the copy you hold.
A match means unchanged since sealing — a fact about the file's bytes, not about what the document says, who signed it or who owns anything.
KuduDoc certifies each sealed PDF with a certificate issued by a certificate authority on Adobe’s Approved Trust List, so Adobe Acrobat shows the document as certified by KuduDoc, with no changes since certification. That tells you who certified the file. The public checker compares the file itself with the sealing record. Seals made before we moved to this certificate show “validity unknown”; check those on the public checker. The guide explains what a PDF reader’s signature messages mean.
For a PDF signed somewhere else, the PDF signature checker shows each signature’s certificate, its issuer and whether the file changed after it was signed.
PDF
Certificate trustCertified by KuduDoc
A certificate Adobe trusts
03 / Timestamp
A pending timestamp is still pending.
The record shows each state of the timestamp anchor on its own: waiting, submitted to the OpenTimestamps calendars, then confirmed in a Bitcoin block. Until that last step, the anchor is pending, not confirmed.
SealedFingerprint recorded
Submitted to calendarsNot yet confirmed in a Bitcoin block
Bitcoin confirmationA later, separately recorded state
Each action sits beside the document: sent, opened, signed, sealed. The record is hash-chained, so it is tamper-evident.
The signing record shows the email address each invitation went to and what each person did.
SentInvitation sent
Link openedThe link was opened. Reading is not established.
CompletedSigning process completed
SealedFile fingerprint recorded
05 / Vault
The Vault is encrypted on your device.
The Library holds ordinary documents. The Vault encrypts on your device with its own passphrase and a recovery key you keep. One Vault per person; Ask never reads it and emergency access never includes it. Account details, item identifiers, encrypted sizes, timestamps and recovery status stay visible to us.
Set up recovery first. If you lose both the Vault passphrase and the recovery key, KuduDoc cannot recover the contents.
VaultOne person holds the keyLocked
Vault opens after recovery is set up.
What you keep here is encrypted on your device with a passphrase only you hold. Save a recovery key before the Vault opens.
Ask reads passages to answer. Consent can be switched off.
Every answer cites the passage it came from, so you can open it. Consent is recorded for your account, and you can switch it off. We do not use your document contents to train AI models — ours or anybody else’s.
AI can misread a document — read the source.
Lease agreement — 12 Oak Avenue.pdfPage 2 of 4
Highlighted: clause 3.2, the passage the answer used1 of 3 citedBack to the answer
2. Period. 2.1 The lease begins on 1 April 2026 and ends on 31 March 2027.
3. Rental and deposit. 3.1 The monthly rental is $14,500.00, payable in advance on or before the first day of each month.
3.2 A deposit of $29,000.00, being two months’ rental, is held in an interest-bearing account. The interest accrues to the Lessee.
3.3 The deposit and its interest are refunded when the lease ends, less any amount lawfully owed.
Passkeys, two-factor, data export and deletion requests.
Sign in with a passkey, or add a second step with backup codes to keep. You can export your account’s personal information yourself, or ask the Information Officer at privacy@kududoc.co.za to tell you what we hold, correct it or delete it. Documents are encrypted in transit and at rest, and staff access is need-to-know.
PasskeysDevice-based sign-in
Two-factorBackup codes to keep
exportAccess your data
Deletion requestAsk us in writing
Deletion cannot recall documents already delivered to a signer or unpublish a public timestamp.
For an employment contract or a family lease, keep the sealed PDF, its kdid and the OTS proof file. The owner can also download a forensic pack. If KuduDoc disappeared tomorrow, the fingerprint and a confirmed public timestamp could still be checked independently.
Judge us by what you can check. A sealed file’s SHA-256 fingerprint is on record, so anyone can check the file free, without an account. Your account can use a passkey or two-factor sign-in. The Vault encrypts on your device with a passphrase only you hold. You can export your data or ask us to delete it.
Does a missing match mean someone tampered with my file?
No. The checker cannot tell a file that was never sealed from one whose bytes have changed.
Does a redacted copy keep the original seal?
No. An edited or redacted copy is a new file with its own fingerprint, so it will not match the original’s seal.
Is all document work done in my browser?
No. The Vault’s encryption and the on-device checker’s hashing happen on your device. Ordinary document processing uses our servers.
Is there a privacy certificate for this software?
No. KuduDoc does not hold a privacy certificate. Read the privacy notice, and write to privacy@kududoc.co.za with any request.