Video content protection
Video content protection from potential deletion and/or infringement is vital to videosurveilance systems. Video content protection implemented by the system is defensive in the following occurrences:
- Efforts to scenes cutting aimed at removing parts containing computer crime evidence;
- Video editing attempts by means of post production instruments and parts erasure and/or alteration
- Attempts of dates alteration in order to offer evidence that recording was made in a different moment from original recording
- Video frames, video sections or video file’s single pixels removal attempts
When the flow transits from NVR to Control Center, the Indigovision system protects the content by means of a technology which operates on two different levels, digital signature and watermarking. Digital signature adopts a powerful cryptography algorithm , obtained via public/private keys exchange; also, digital signature is masked in the video by use of watermarking proprietary algorithm.
The digital signature in a file is obtained thanks to application of a hashing algorithm (standard SHA-1) which produces a big size numeric value defined as checksum, in turn encrypted by usage of private key, a binary string of more than 1024bits (RSA standard).The mechanism is based on the fact that it is impossible to modify an original video file and to avoid hashing algorithm from producing apposite checksum of original file: this way a one bit alteration is suddenly detected.
Watermarking is the process that adds visible and invisible information to videos; in the suggested system, it is used to hide digital signature and to increase security, thus preventing video violation. Authentication process: once exported, the video can’t be modified if not processed previously by authentication software.