Privacy Policy - Protochrome

What Data is Collected
The purpose of this service is to provide a means to verify whether a photo has been altered after it was taken. To do this, the service must collect some information about the photos taken with the app. The app applies a cryptographic hash function to the image, and the resulting digital signature, in the form of a 64-character string of text, is collected and stored for verification. No other user-generated information is collected by this service.
How the Data is Collected
Whenever a photo is taken with the app, the digital signature is generated on the user's device and is then sent to the service to be stored. The service also stores the time at which the signature was received. The digital signature is not tied to any identifying factor of any person and is thus does not constitute personal data. No personal data is stored.
How the Data is Used
The data is freely available to the public. The typical way in which the collected data is used is that a user asks the service whether a particular digital signature has been stored, and if it has, the service tells the user at what time the signature was stored.
A copy of the data may also be provided to other services for the purpose of preservation and resilience.
If you wish to contact the maintainer of this service with any questions or concerns, please send an email to eli173 at