This URL is not a website
You are looking at the time-stamping endpoint of open-tsa.eu, a free and open Time-Stamp Authority based in Germany. This endpoint speaks RFC 3161 — a binary protocol used by software to obtain cryptographically signed proof that a digital document existed at a specific point in time.
If you arrived here from a verification page of a time-stamped
document: this is the correct authority. The endpoint is intentionally
machine-only — it accepts POST requests with
Content-Type: application/timestamp-query.
What is a qualified time-stamp?
A qualified time-stamp binds a cryptographic hash of your document to an authoritative UTC time, signed by a trusted authority. In court it serves as evidence that the document existed unchanged at that moment — admissible under § 371a ZPO (Germany) and eIDAS Art. 41 across the EU.
Verification is independent of open-tsa.eu itself — our certificate chain is public, and anyone can validate a time-stamp offline with standard OpenSSL commands.
Technical details
- Endpoint
- https://tsr.open-tsa.eu/
- Protocol
- RFC 3161 (TSP over HTTP)
- Method
- POST
- Content-Type (request)
- application/timestamp-query
- Content-Type (response)
- application/timestamp-reply
- Hash algorithms
- SHA-256, SHA-512
- Authentication
- none (free service)
- Rate limit
- Fair use — see open-tsa.eu
Try it from the command line
Create a request from any file, post it to the endpoint, verify the reply:
# 1. Create a time-stamp request from a file
openssl ts -query -data ./document.pdf -sha256 -cert -out request.tsq
# 2. Submit the request
curl -s -H "Content-Type: application/timestamp-query" \
--data-binary @request.tsq \
https://tsr.open-tsa.eu/ \
-o response.tsr
# 3. Verify against the public certificate chain
curl -s https://open-tsa.eu/certs/chain.pem -o chain.pem
openssl ts -verify -data ./document.pdf \
-in response.tsr \
-CAfile chain.pem