Timespace X300 Mark 2, Instruction Manual

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X300 Instruction Manual Chapter 4 - System Information And Security
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4.8 Watermark and Sequencing
4.8.1 Watermark
The X300 uses a fragile watermark. Any modification to the recorded file will destroy the watermark.
The image, audio and ancillary (meta) data that makes up the recorded file is passed though a
function that generates a "magic number" or hash code from the data. A hash code is created
automatically by the X300 every ¼ of a second for each ¼ second of data. Each hash is then passed
though an encryption function and then stored in the file.
A sequencing number ensures that all hash codes and corresponding data are present and where
multiple files exist that no files are missing.
To check that a number of files have not been altered or modified in any way, the watermark
checking program (e.g. PCLink) recalculates the encrypted hashes (watermarks) and checks these
against the watermarks provided in the file. If all the watermarks match the recorded file has not
been tampered with. The watermark is "destroyed" when the encrypted hash code stored in the file
and the encrypted hash code of the data do not match. PCLink produces a report which can be used
in court to validate recorded files.
The watermark is always on the X300 i.e. all recordings have the watermark embedded in real-time
as the footage is laid to disk, it cannot be turned off. Within PCLink200, you can generate a report for
a number of files. You can also select a file for watermark checking.
Encryption type;

Hashing function: SHA256

Encryption function: AES256
4.8.2 Sequencing
In addition to every ¼ second being protected by a Watermark, each watermark has its own unique
sequence number. This protects any images being removed from a file and protects any files being
removed from a sequence of files.