Video authentication manual – Quadrox Video Authentication User Manual
Page 18
Video Authentication Manual
18
Version 4.4 Series
A hash value or a checksum for a file is a short value, something like a fingerprint of the file.
This feature can be useful both for comparing the files and their integrity control.
A hash is a mathematically calculated number that uniquely defines the original information.
There are always several information strings that have the same hash as a result, but it is
infeasible to find a “second original” based only on the hash. If you change a single bit in the
original information, the hash will be different. Popular hashes used by the Quadrox software
are MD5 and SHA-1.
The Hash value can be checked by using the special tools which are built upon the MD5
checksum algorithm which is used worldwide for checking the integrity of the files, for
example FastSum application (
http://www.fastsum.com
).
Calculate movie hash value by means of the
FastSum application
Follow the steps below:
1.
Download and install the FastSum application by using all the default settings.
2.
Right-click on the export file and make the selection as shown on the following
screen.
Create Checksum Selection Screen
3.
Click F9 button in the FastSum screen that appears to begin the calculation.
4.
When the checksum is calculated by means of FastSum, compare it with the one from
the digital signature.