Photo Timestamp for Evidence: A Tamper-Evident Workflow
When you timestamp photos for evidence, a visible date helps people read a photo. A tamper-evident workflow also needs a way to detect later changes and establish when a particular file existed.
When the date on a photo needs more support
Whether you need a photo timestamp for insurance claims, construction handovers, or legal disputes, the question is the same: how can someone check whether the photo or its claimed time has changed? A printed date alone cannot answer that question. Keep the original file and a record of how you handled it, and check the recipient’s evidence requirements.
What the editor does today: visible stamps and EXIF
EXIF is metadata stored inside a photo and may include a camera-recorded capture time. A visible timestamp is text rendered into the exported image’s pixels. Photo Timestamp can read EXIF capture time and lets you choose the stamp’s format, position, and font, with batch processing and Pro options for custom date formats. Photos are processed locally in your browser and are not uploaded to our servers.
Neither an EXIF date nor a visible stamp independently verifies when a photo was taken. EXIF may be missing, a camera clock may be wrong, and dates can be edited. The current editor does not create a cryptographic verification record.
What makes a timestamp verifiable
The following three elements describe the roadmap direction for the Verified Timestamp Generator. This generator is not available yet; the current editor does not provide these verification features.
A content hash
Compute a cryptographic fingerprint of the exact file being anchored. A later file can be hashed again and compared with that fingerprint to detect changes to its bytes, including metadata changes.
Trusted time anchoring
Bind that hash to an independently verifiable time record. This can support a claim that those exact bytes existed by the anchoring time; it does not establish the camera’s capture time.
Public verification
Provide a verification record and a documented way for others to check the hash and time anchor independently. A verifier would need the exact anchored file; a resized or re-exported copy has different bytes.
The boundary: capture time and anchoring time
EXIF can be modified with editing tools after capture and before anchoring. A tamper-evident record cannot recover that earlier history or prove that a scene is authentic. Its value is that changes after anchoring become detectable and the anchoring time can be checked against a trusted time source. The record does not prevent editing; it makes a changed file fail verification against the original anchor.
A practical workflow to prepare now
- Keep the original camera file untouched and backed up; work on a copy.
- Inspect the EXIF time and document any known camera-clock issues. Do not treat an editable date as independent proof.
- Use the local editor to export a readable, visibly stamped copy for sharing. Keep that copy separate from the original.
- When the planned generator becomes available, follow its published instructions to anchor the chosen file and retain its verification record. Any original and stamped derivative would need their own hashes.
Frequently asked questions
What is the difference between EXIF and a visible timestamp?
EXIF stores metadata such as a camera-recorded capture date inside the file. A visible stamp renders text into the exported image. Either can help organize photos, but neither independently verifies a capture time.
Does adding a timestamp change my original photo?
The browser editor creates a new stamped download and does not overwrite the original file on your device. The exported image has changed pixels and a different hash; keep your original separately and do not assume all original metadata is preserved in the export.
Will my photos be uploaded to a server?
The current editor processes photos locally in your browser. Photo files are not uploaded to our servers. Joining the waitlist sends your email address and signup source so we can record your interest and email you about launch. The roadmap generator’s design and privacy details will be published before launch.
Can a photo timestamp be forged?
Visible dates and EXIF can be edited, including before any anchoring step. The planned tamper-evident workflow would let someone detect changes after anchoring and verify the anchor’s time, rather than prove that the camera’s original date was correct.
How many photos and which formats can I process in a batch?
The free editor supports up to 5 photos per batch. Pro removes the plan’s batch-count limit, although practical capacity depends on your device’s memory. The editor accepts JPEG, PNG, and supported HEIC/HEIF photos; HEIC/HEIF compatibility depends on the file and browser. Stamped downloads are JPEG copies.