照片来源封签·Photo Provenance Seal

How checks work

L-07 records a fingerprint of your exact file. Independent timestamping is not yet integrated: the time shown comes from /land's own clock. The record is signed and publicly logged, so changes to the record can be spotted. Anyone with the link can check whether their copy is that file, and if it isn't, get a clearly labeled estimate of how it compares.

Limits

• It can't stop anyone from editing, screenshotting or using AI to re-generate the photo.
• It doesn't prove the photo is real, unstaged, or unedited before it was sealed.
• It doesn't prove who took the photo, who owns it, or who is in it.
• A photo without a seal isn't suspicious. Most photos are never sealed.
• It doesn't detect or recognize faces or identify anyone.

Disclaimers

• A seal records a file and a time it existed by. It doesn't prove the photo is real, unedited or unstaged.
• Sealing can't stop anyone from editing, screenshotting or generating images. It only lets people check a copy against the sealed file.
• No seal, or a copy that isn't an exact match, doesn't mean a photo is fake.
• 'Sealed by' means a /land account submitted the file, not that it took or owns the photo.
• Results marked S are estimates. They can miss small edits, including a changed face in a large group photo, and can flag harmless changes.
• L-07 doesn't detect or recognize faces or identify people, and it doesn't store your photo.
• If you're in a sealed photo, you can report it. No account needed.

No face processing

L-07 doesn't detect, locate, recognize or measure faces, bodies or any other biometric characteristic, and treats them no differently from any other part of the image. It creates no face embeddings or templates, keeps no identity database, and offers no way to search for a person. It stores and compares only coarse fixed-grid block fingerprints of the whole image, computed the same way on every block whether it shows a face, a wall or the sky; they are not designed or used as face templates. Whether such fingerprints are regulated data is under legal review. Adding any face-aware feature would require a new privacy and legal review.

L-07 不检测、不定位、不识别、不测量人脸、身体或任何其他生物特征，对它们的处理与图片其他部分没有任何区别。它不生成面部特征向量或模板，不建立身份数据库，也不提供按人查找的功能。它只保存和比对整张图片的粗粒度固定方格指纹，对每个方格做同样的计算，无论其中是人脸、墙壁还是天空；这些指纹并非为用作面部模板而设计，也不会被这样使用。这类指纹在法律上如何定性，正在进行法律审查。增加任何与人脸相关的功能，都必须重新进行隐私和法律审查。

RFC 3161 timestamps and external log witnesses are not attached in this experimental build; those O lines show as pending. Server time is never an O input.