A Durable Medium is a secure digital place where you can always access important ZEN.COM documents, such as Terms & Conditions or Pricing Lists. Once a document is published there, it cannot be changed. You can return to it at any time and be sure it is exactly the same version as on the day it was issued.
Why you might need a Durable Medium
When it comes to legal or pricing documents, certainty matters. A Durable Medium gives you that certainty.
Each document published by ZEN.COM comes with a unique SHA-256 checksum. Think of it as a digital fingerprint that proves the file has not been altered. Thanks to this, you can:
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Keep your own copy
Download the PDF and store it wherever you like. -
Confirm it’s authentic
Check that your file matches the official version. -
Access it anytime
Even years later, with no risk of silent changes.
How ZEN.COM uses the Durable Medium
Whenever Terms & Conditions or Pricing Lists change, we:
- Publish the new document on the relevant page:
- Inform you by email about the update and include the SHA-256 verification code.
- Share a link to the dedicated ZEN.COM Durable Medium page, where you can verify the document.
This way, you always know which version applies to you.
How to verify a document step by step
- Download the PDF with the ZEN Terms that apply to you from the ZEN.COM Terms & Conditions page.
Always choose “Save file”, not “Open with”. Preview modes can change the file and break the SHA-256 checksum. - Open the email about the update to ZEN Terms and copy the SHA-256 checksum provided there.
- Go to the ZEN.COM Durable Medium page.
- Upload the PDF file and paste the SHA-256 checksum from the email.
- Choose “Verify”.
What the verification result means
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“The file has been successfully verified”
Your document is identical to the official version stored on ZEN.COM servers. -
“File verification error”
The file is different from the official version, or it is a version published before the introduction of a Durable Medium (20.08.2025).