Video Encryption

What is Video Encryption?

Video Encryption is a very useful method for stopping unwanted interception and viewing of transmitted video or other information, for example, a video surveillance system contrast transmitted to a central display center.

The encryption system is the easy part. E 'UN encryption difficult, but there are various techniques available. However, the human eye is very good, spotting distortions in pictures because of the poorVideo decoding or poor choice of video encoding hardware. E 'therefore very important that the right hardware, or it can choose the video transfers UN-Secure or video is watchable not be decoded.

Some of the most popular techniques are listed below:

Line Reversal:

Method: all or part of the signal scan lines are reversed.

Advantages: Simple, low-cost video encoding.

Disadvantages: Poor quality video decoding, dark bass, bassSecurity.

Sync Suppression:

Method: Hide / remove the horizontal and vertical syncs.

Advantages: Provides a convenient solution for encryption and decoding video offers a good quality.

Disadvantages: This method is incompatible with some distribution systems. Darkness (ie how easy it is to decode the visual image) depends on the video content is.

Line Shuffle

Method: Each wire is again positioned on the screen.

Advantages: Provides a compatiblevideo signal, an appropriate amount of darkness, for decoding of high quality.

Disadvantages: Requires a lot of digital storage space. There are potential problems with the stability of the videos. less secure encryption method that the shear and rotation (see below)

Cut & Rotate:

Scrambling Method: Each scan line is cut in pieces and then cut back together in a different order.

Advantages: Provides a compatible video signal, is an excellent amount of obscurity, and decoding and high qualityStability.

Disadvantages: May have a calendar control complex and requires specialized equipment Scrambling

Cutting and rolling video encryption method is probably the best way to get reliable, high quality video encoding, an example of a good implementation of this system is in the second Viewlock

Implementation Deputy Scrambling

The video encoding hardware, in particular, the decoder should function correctly even if there is a strong, for example, what are (commonly referred to as "snow" known on the screen. "Snow" is, if the patches on the TV screen, often seen in areas with poor reception) or unstable signals. If the link should be encrypted signal to stop working, this should be a problem. The connection between the video encoder and video decoder to decode quickly and is back on.

The nature of systems of surveillance cameras is often open as it should be able to withstand the rigors of time.The video encryption hardware should be stable or protected from the effects of rain, sun, extreme heat and cold. Not be damaged if it is a peak power in the supply chain. In these systems the video signal encoder, a video-decoder wireless units, before it is displayed, it must be the case, of course, that the act of transmission of the signal has no effect for the video encoding hardware and video hardware encryption should not affect the radioTransmitter.

The most important point is that the video Scrambling System should be safe, otherwise why make the effort? It 's amazing how some encryption methods can be broken easily. For example, some cable TV channels to encrypt 'their channel broadcasts via a relatively complex method of the United Nations, which can be easily decoded with a number of bits cheap electronics from Radio Shack are. This, of course, illegal! The method of cable TV encryption is very crude, but usually only dynamicallychange the vertical sync signal, so the TV can not obtain a lock on him real well and runs randomly.

The other extreme is the encoding of the video signal too, so it is expensive, both in equipment and time to the video receiver. Remember that this is a "system of transmitting live video encryption,''a display live video decryption follows. ANY electronics can be copied, because enough money and time, but makes this process as possible is beneficial, since at leastDelays when illegal copies will be available.

Finally and most importantly, each user must have a unique key, so that other users of the system can not be transferred to the knowledge of the video of an accident or purpose without the key owner. The number of possible user keys must be such that it is highly unlikely that someone has guessed the right key.