- Setup
2. Recording
F/P allows you to record several tracks of data, simultaneously, into a single standard MP4 file that is compatible with normal media tools.
Video tracks -- F/P can record simultaneously from the front and rear cameras
Audio track -- just your standard phone microphone
Location track -- a stream of phone's GPS coordinates
Sensor track -- a stream of the phone's internal sensors (magnetometer, accelerometer, etc)
F/P uses several methods to protect against manipulating or faking these tracks. These include:
cryptographically signing the recording streams (eg video and audio)
this prevents modification of the recording, and proves that it was generated by your username
syncing timestamps with the F/P Server
this proves that the recording was taken at a specific time -- prevents anyone presenting an old recording as new!
embedding phone location and sensor data in the recording
this proves the location of the recording, and can be used to validate video and audio streams (for example, they can prove that someone didn't just take a new recording of a manipulated video being played on a high resolution screen!)
New! Android SafetyNet attestation
New! OpenTimestamps bitcoin blockchain attestation
There are several other more sophisticated methods under investigation.
3. Verifying
Each F/P recording stores all the information needed for verification, including metadata, signatures, and sensor data. To verify a F/P recording, simply open it in the F/P App and click Verify (note: this requires an internet connection so that the F/P Server can be consulted for signature and timestamp validity). You can use any common file sharing method to exchange recordings -- though some systems may re-encode the recording which will destroy the F/P side-channels.
NOTE: Absolutely no personal information or any of the content of your recording is shared with the F/P Server. The only information shared and stored is:
your chosen username and your F/P public key -- a public cryptographic key generated for you by the F/P App. The private key is stored only on your phone.
Start and Stop Timestamps for each recording, as well as a cryptographic digest of the recording contents, and a cryptographic signature from the F/P App Key and from your F/P User Key.
