Terms of service

Last reviewed 29 October 2026 (Content Credentials, the hidden watermark and the picture note now described exactly as they work).

Who is offering KolTheia

KolTheia is run personally by Njinwi Ngu-Ngwa, an individual. There is no company behind it yet, so when you use KolTheia you are dealing with that person, not with a company. If a company is set up later, these terms will say so and you will be told. Contact: koltheia@ottxp.com.

What KolTheia is

KolTheia does two separate things. It seals a photo or video at the moment it is captured, so that anyone can later check that a file is the one that was sealed, when KolTheia received it, and which device sealed it. And it registers any file you already have, so that anyone can later check that those exact bytes were registered by your account at a given time, before anyone else. You seal from the capture page and register from the Register page; anyone can use the Verify page, and open a certificate, without an account. KolTheia is free to use today.

What a seal does, and does not, prove

• It shows that a particular device, holding a particular key, signed the file it captured at the time shown; that KolTheia received exactly that file, made the sealed copy it handed back, and recorded both; and that the sealed copy has not changed since. The sealed copy is not byte for byte the file the device signed (KolTheia adds its credentials to it, and a video is re-encoded), and the record links the two.
• It does not prove that what the picture shows is true, that the scene was not staged, or that nobody pointed the camera at a screen. The place and time come from the device and are labelled as reported by it.
• On a web capture, KolTheia cannot ask Apple or Google whether the phone and the app are genuine. The certificate says "platform integrity: unavailable" for that reason.
• A file that is not the exact sealed file (for example one a messaging app has recompressed, or that has been resized, cropped, shortened, given a filter or had something added) cannot be proven exact. The Verify page can compare such a copy with the note KolTheia keeps about the sealed photo or video and tell you what it found: that it was recompressed, resized, cropped, shortened (for a video, and which seconds are left), mirrored, turned, given a filter, or has something introduced in one place. These are findings in the places checked, not guarantees: "recompressed" means no difference beyond recompression was found, not that the copy is the original, and a very small or short change can be missed. A copy that has been changed in a way KolTheia cannot trace is reported as not verified, which does not mean it is false.
• Every sealed file also carries Content Credentials: a signed note in the open industry standard (C2PA) that other apps and checkers can read without KolTheia. They are signed by KolTheia's server, not by your phone. Inside them is your device's own signature over the file it captured, so the capture proof can be checked from the file alone. When the outside time-stamp authority answers while sealing, they also carry its signed time. KolTheia's signing certificate is not yet on the official C2PA trust list, so other checkers show the credentials as intact but signed by a signer they do not recognise. Like the seal itself, the credentials prove only the exact sealed file: any change to the file breaks them. KolTheia's hidden watermark is switched off at the moment for photos and videos, so a sealed file carries none.
• Please do not present a KolTheia seal as more than this.

What a registration does, and does not, prove

• It shows that a file with this exact fingerprint (SHA-256) was registered by this account at the time shown, that no one registered the same bytes with KolTheia before it, and, once the outside time-stamp authority has answered, that the bytes existed no later than the time that authority signed.
• It does not prove that you made the file, that you own it or hold any right in it, that the file is real or unedited, or what it shows. Anyone can register a file they have: a registration says who registered it first with KolTheia, nothing more. It is not a copyright registration, a patent, a trademark or any other legal title.
• It covers the exact bytes only. A copy that has been re-saved, converted, compressed, cropped or edited in any way has a different fingerprint and is not covered.
• KolTheia never receives the file: your browser works out the fingerprint and sends only that, with the file's name, its size and any description you add. So KolTheia cannot tell you what a registered file contained; keep your own copy.
• A file that is already a KolTheia capture cannot be registered: its capture certificate already proves when it existed.
• If a registered file is sold through a service that works with KolTheia, a transfer can be added to the record. A transfer shows who holds the file now; it never changes who registered it first, and it is only as good as the sale behind it, which KolTheia does not check.
• Please do not present a KolTheia registration as more than this.

Your account

You create an account with your email address and a password, and confirm the email with a code we send you. After that you sign in with your username or email and your password, or with a passkey if you add one. An emailed code is only used to confirm a new email address and to reset a forgotten password. You must give a real email address that you control.

Keep your password and passkeys to yourself, and tell us at once if you think someone else has used them. You are responsible for what is done with your account. You must be at least 13 years old, or old enough to agree to these terms where you live if that is higher.

Your username is public: it is shown to anyone who checks one of your captures. Your email address is not.

What you may do

Use KolTheia for lawful purposes and in line with the acceptable use page. In short: do not use it to deceive people, to seal material you have no right to capture or share, to harass anyone, to attack or overload the service, or to try to read other people's records. We may refuse or end access if these terms are broken.

Your files

Your photos and videos stay yours. KolTheia does not keep your file: it holds the sealed copy in memory for up to 15 minutes so your phone can collect it, then deletes it. It keeps a record of the capture (the proof code, fingerprints of the file, times, the area where you were, and the device's signature) and, for every photo and video, a small note about its pictures (a coarse description of points and small squares, used only to recognise copies of it and say what was done to them). The note is not a copy of your file and cannot be played, but a coarse, blocky picture can be rebuilt from it, as the privacy notice explains; it is never shown to anyone. See the privacy notice for the detail. Keep your own copy of anything that matters: after the 15 minutes, a sealed file cannot be downloaded from KolTheia again.

You confirm that you have the right to capture and seal what you capture, and you are responsible for it. KolTheia does not look at the content of what you seal.

When you register a file, you confirm that you have it lawfully and that the name and description you give it are not misleading, private to someone else, or unlawful: they are shown to anyone who opens the registration. Registering someone else's work to pass it off as yours is against these terms. If you believe a registration is being used to make a false claim about your work, write to koltheia@ottxp.com; we will look into it and can end the account behind it, but, as with captures, we do not erase the record itself.

Records are meant to last, and parts of them are public

A proof record is written to a public log so that it cannot be quietly changed. The public log shows the proof code, a name for the device, fingerprints of the file, the times, and the label you give a capture. Do not put anything private in a label. It does not show your email, your photo or video, or your location. A registration is written to the same log with its code, the file's fingerprint, the time and your username (who registered first is the whole point of it); the file's name and description are shown on its certificate, not in the log. Registrations are not erased either.

We do not erase capture records. A record is proof, and proof that could be quietly removed would not be proof. You can hide a capture from your account yourself on My Captures, or ask us to (see your data): it is no longer listed in your account, and your username and the area no longer appear on its certificate page. Hiding cannot reach copies other people hold: anyone who already has the photo or video, or its proof code, can still check it and find its record. The file itself is never part of the record, and neither is a playable copy: the note about a capture's pictures is not a copy of the file, is never shown to anyone and is not in the public log.

The service

KolTheia is provided as it is, and free. We work to keep it running and correct, but we do not promise that it will never be interrupted or wrong, or that a particular result will be accepted by anyone else. To the extent the law allows, we are not liable for indirect or consequential loss, and our total liability to you is limited to what you paid us for KolTheia in the twelve months before the claim. KolTheia is free, so today that amount is nothing. Nothing here limits liability that cannot be limited by law.

Prices

KolTheia may later offer paid plans. Anything already sealed or registered stays valid and verifiable whatever plan you are on. We will tell you before any charge applies to you.

Changes and ending

We may change these terms and will say so on this page, with a new date; if a change matters to you we will also tell you by email. You can stop using KolTheia at any time and can ask us to delete your account (see your data). We may suspend or end an account that breaks these terms, and we may change or stop the service.

The law, and contact

If you are a consumer, you also keep any rights the law of the place where you live gives you that cannot be waived. Contact: koltheia@ottxp.com. To report a security problem, see security.