Terms of Service

Last updated: October 2026

This English translation is provided for convenience; the German version (Nutzungsbedingungen) is binding. Also in Polski.

1. Scope and provider

(1) These Terms of Service apply to the use of Sigelith (formerly BeatTime): the website sigelith.org (also reachable at beattime.live and as an onion service on the Tor network), the public application programming interface (API), the programs Sigelith Desktop and Sigelith Backup for Windows, the Android apps BeatTime (with a watch face for Wear OS), Sigelith Courier and Sigelith Delivery, the browser extension, the WordPress plugin and the software libraries (SDKs) — together, the “Service”.

(2) The Service is provided by (“we”):

“W3 eXperts” and “Advena Partners” are brands of Adam Koch. Full provider details are in the Impressum.

(3) Voluntary support is additionally governed by the Bedingungen für Unterstützungen (conditions for support; the German version is binding). If you obtain an app from an app store, that store’s terms apply in addition; open-source programs are governed by their licences.

2. What the Service does

(1) Timestamps. Your device computes a fingerprint (SHA-256) of a file. Only this fingerprint — never the file — is sent to the Service and entered, with the time of entry, into a public log that can only be appended to, not changed. The log is signed every day and anchored in Bitcoin through OpenTimestamps; every week it is also anchored with a bank transfer and copied to public archives. For every entry you receive a signed receipt and, on request, a PDF certificate and a proof file.

(2) Verification. Proofs can be checked on the website, in the apps and through the API — and without our software, following the published specification.

(3) Time capsules. Content is encrypted on your device; the key is split so that the capsule can only be opened after the chosen moment. We receive neither the content nor the key.

(4) Handover. Programs with which two parties hand over files and prove acceptance. The parties transfer the files themselves; the Service only timestamps fingerprints.

(5) Sigelith Courier and Sigelith Delivery. Apps and a confirmation page with which shops, courier services and recipients document the hand-over of a shipment.

(6) @beat. The clock divides the day into 1000 beats and counts from midnight UTC — not by Swatch time (Biel, UTC+1).

3. Free of charge; voluntary support

(1) The Service is free. It requires no account and is not provided for remuneration; there are no paid services.

(2) Voluntary support (tips) consists of gratuitous contributions without anything in return. A tip buys nothing: it unlocks nothing and creates no claim to services, availability or help with questions. Tips are income of the provider, not payment for the Service; the Service is available to everyone in the same way, whether they support it or not. Details are set out in the Bedingungen für Unterstützungen.

4. What a timestamp proves — and what it does not

(1) An entry proves that the fingerprint was presented to the Service no later than the recorded time and that the entry has not changed since. Whoever has the file can use it to show that the file existed at that time and has not changed since.

(2) An entry does not prove who created the file or who owns it, whether its content is true, whether anyone read it, or that it reached anyone in the legal sense.

(3) Sigelith is not a qualified trust service provider within the meaning of Regulation (EU) No 910/2014 (eIDAS Regulation), is not listed in any trusted list and does not issue qualified electronic time stamps. The Service’s timestamps therefore do not have the legal effects of qualified electronic time stamps; how they are weighed as evidence is for the court or authority concerned to decide. We do not warrant that a timestamp will be accepted in any particular proceedings.

(4) Entries are public and permanent; they cannot be deleted. A fingerprint does not reveal the file, but for short or guessable content it can be found by trial. Do not timestamp a fingerprint that must stay secret.

5. Time capsules

(1) You are responsible for keeping the capsule file and — depending on the chosen profile — the recovery code. We cannot restore lost capsules or codes, and we cannot open any capsule early.

(2) Opening requires shares held by third parties (the drand network and key servers). We do not warrant that these third parties will still be available at the moment of opening. What happens if individual shares are lost is described for each profile on the Time capsule page.

6. Handover, Sigelith Courier and Sigelith Delivery

(1) These programs run on the devices of the parties. The parties transfer the files and the shipment data among themselves; we do not store or transmit them, send no notifications and keep no accounts. Only fingerprints reach us, for timestamping.

(2) We do not provide an electronic registered delivery service. A Handover proof is not proof of service within the meaning of statutory formal requirements.

(3) We are not a party to the contracts between shops, courier services and recipients.

7. Google Calendar in the BeatTime app

Google sign-in is optional and only used if you connect Google Calendar. In that case:

• we request only the scope needed to read your events and add events you create or tag;
• your authorization stays on your device — we do not store calendar contents on our servers, and we do not sell, share or use your Google data for advertising;
• our use of information received from Google APIs adheres to the Google API Services User Data Policy, including the Limited Use requirements;
• you can revoke access at any time at myaccount.google.com/permissions.

8. Acceptable use

You may not:

• use the Service for unlawful purposes or to infringe the rights of others;
• attack, disrupt or overload the Service or circumvent the published rate limits of the API;
• present timestamps of the Service as qualified electronic time stamps or as official or notarial confirmations;
• use the names Sigelith or BeatTime or their logos in a way that suggests a recommendation, partnership or review by us.

9. Availability and changes to the Service

There is no entitlement to the availability of the Service. We may change, restrict or discontinue the Service and individual features at any time. The log and its public copies are designed so that existing proofs remain verifiable without us; this is no promise that third-party archives will always remain available.

10. Liability

(1) We are liable without limitation for intent and gross negligence, for damage arising from injury to life, body or health, and under the German Product Liability Act (Produkthaftungsgesetz).

(2) Otherwise we are not liable for slight negligence, because the Service is provided free of charge.

(3) We are not responsible for the availability or conduct of third-party services on which the Service relies or to which it refers — such as the Bitcoin network and the OpenTimestamps servers, the drand network, key servers run by other operators, GitHub, the Internet Archive, Zenodo, payment providers and app stores.

11. Content, licences and names

(1) Your files stay with you; we receive only their fingerprints.

(2) We dedicate the entries of the public log and the checkpoints to the public domain (CC0 1.0).

(3) Open-source programs are governed by their licences; which programs are open source is listed at sigelith.org/open-source/. The names Sigelith and BeatTime and their logos may not be used in a way that suggests something comes from us or is recommended by us.

12. Privacy

How we process personal data is explained in the Privacy Policy (English translation of the binding Datenschutzerklärung).

13. Changes to these Terms

We may change these Terms with effect for the future. The version published on this page at the time of use applies; the date at the top shows the current version.

14. Governing law, disputes, language

The law of the Federal Republic of Germany applies. If you are a consumer, mandatory consumer protection provisions of the country of your habitual residence remain unaffected. We are neither willing nor obliged to take part in dispute resolution proceedings before a consumer arbitration board. The German version of these Terms is binding; translations are for information only.

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