Effective date: September 8, 2026
Our website is https://proofstamp.org.
ProofStamp is designed to minimize the data we receive.
Where a ProofStamp tool says that a file is processed locally, the file stays on your device. We do not receive the file simply because you calculate its SHA-256 hash.
This policy explains what information may be processed when you visit ProofStamp.org or use ProofStamp tools.
Files and content you ProofStamp
ProofStamp tools may calculate a cryptographic hash, such as SHA-256, directly in your browser or on your device.
Where a tool states that local processing is used, the original file remains on your device and is not uploaded to ProofStamp simply in order to calculate its hash.
A hash is derived from the contents of a file. It is not the original file and is not intended to allow the file to be reconstructed.
Only information required by the particular proof workflow may be transmitted.
If a specific ProofStamp tool works differently, that tool should explain this before you use it.
Public proofs
Some ProofStamp tools can create proofs using public blockchains or timestamping systems.
Information required to create the proof may therefore become public and may remain available indefinitely.
Depending on the system, this may include:
- a cryptographic hash or derived commitment
- timestamp
- transaction identifier
- blockchain address
- network information
The underlying private file is not normally placed on the public network.
Public blockchain records may be impossible for ProofStamp or anyone else to modify or delete.
Do not intentionally include personal, confidential, or sensitive information in a public transaction unless you understand the consequences.
Information you give us
We receive information that you intentionally provide to us.
For example, if you use our contact form or send us an email, we may receive your name, email address, message, and other information you choose to provide.
We use this information to respond to you, understand your request, operate ProofStamp, and improve the project.
Please do not send unnecessary sensitive or confidential information through a contact form or ordinary email.
Website and technical data
When you visit ProofStamp.org, the website and its infrastructure providers may process technical information necessary to deliver and secure the site.
This may include:
- IP address
- browser and device information
- operating system
- pages requested
- date and time of requests
- referring page
- security and diagnostic information
This information may be used to operate the website, prevent abuse, maintain security, and diagnose technical problems.
Cookies and local browser storage
ProofStamp.org may store limited information on your device using cookies, local storage, session storage, or similar browser technologies.
This may be used for website operation, security, preferences, administrative functions, or application functionality.
For example, WordPress may use cookies for administrator login sessions and interface preferences.
Some ProofStamp applications may also keep information locally in your browser so that they can work without sending that information to ProofStamp.
Information stored locally is not automatically transmitted to us merely because it exists in your browser.
We aim to avoid unnecessary tracking.
Website caching
ProofStamp.org uses caching to improve site performance and response times.
Caching may temporarily store copies of publicly displayed pages.
Cache files are temporary and expire according to settings maintained by the site administrator. They may also be manually deleted before their normal expiration.
ProofStamp.org may use QUIC.cloud services to process and cache website data temporarily.
QUIC.cloud has its own privacy policy:
Caching of public website pages is separate from ProofStamp’s local file-processing functions. A private file that a ProofStamp tool processes locally is not uploaded merely because the ProofStamp.org website uses caching.
Embedded content
Articles and pages on ProofStamp.org may contain content embedded from other websites, such as videos, images, social posts, or other external resources.
Embedded content can behave as though you visited the third-party website directly.
Those websites may collect technical information, use cookies, or record your interaction with the embedded content according to their own privacy policies.
ProofStamp via email
Some ProofStamp tools can prepare information for you to send through your own email application.
That information may include a hash, filename, file size, media type, description, verification information, recipient address, or other information you choose to include.
Where the tool opens your email application, you decide whether to send the message.
Your email provider and the recipient’s email provider process the email under their own privacy policies.
ProofStamp does not receive a copy merely because a ProofStamp tool prepared the email.
Comments
If comments are enabled on ProofStamp.org, WordPress may collect the information entered in the comment form together with the visitor’s IP address and browser user-agent information to assist with spam detection.
Comments may also be processed by an automated spam-detection service.
If ProofStamp.org does not allow public comments, I would remove this section entirely.
Media
If ProofStamp.org allows users to upload images publicly, uploaded images may contain embedded metadata such as EXIF GPS location information.
Visitors may be able to download those images and extract that information.
Again, if visitors cannot upload media, we should remove this section rather than include generic WordPress boilerplate.
Third-party services
ProofStamp may use or interact with third-party services, including:
- website hosting and security providers
- QUIC.cloud
- email providers
- blockchain networks
- blockchain infrastructure providers
- timestamping systems
- GitHub
- AI platforms
- embedded media providers
These services have their own privacy policies and terms.
When you choose to use a ProofStamp workflow that depends on another service, that service may process the information required to provide it.
Data retention
ProofStamp does not intentionally retain original files when a tool states that those files are processed locally.
Information you deliberately send to us may be kept for as long as reasonably necessary to respond to you, maintain project records, prevent abuse, operate the service, or meet legal obligations.
Website and security logs may be retained by ProofStamp or its infrastructure providers according to their operational requirements.
Website cache files are temporary.
Public blockchain or timestamp records may remain available indefinitely.
Your rights
Depending on where you live, you may have rights concerning personal information we hold about you, including rights to request access, correction, or deletion.
If information remained entirely on your device, ProofStamp has no copy to retrieve or delete.
Likewise, ProofStamp cannot delete records from public networks designed to be immutable.
You may contact us regarding information that you have directly provided to ProofStamp.
Security
We use reasonable measures intended to protect information handled by ProofStamp.
An important part of the ProofStamp approach is data minimization. Where practical, private content remains on your device rather than being transmitted to us.
No online system can guarantee absolute security.
Children
ProofStamp is not specifically designed for children, and we do not knowingly seek to collect personal information from children.
Changes to this policy
We may update this policy as ProofStamp, its website, or its infrastructure changes.
The effective date at the top of the page indicates the latest revision.
Contact
For privacy questions or requests, contact us through: