Video: Hacking ATSC 3.0

ATSC’s effort to bring IP into over-the-air broadcast has been long in the making and its deployment in South Korea along with the ITU’s inclusion of it in it’s list of recommended digital broadcast standards is a testament to it gaining acceptance. But as US broadcasters continue with test broadcasts and roll-outs in 2020, what security problems arise when IP’s included in the mix?

Acting is a great network security primer, this talk from Texas A&M’s Wayne Pecena, explains the premise and implications of creating and maintaining security in your broadcast plant. Starting by documenting the high profile attacks on broadcasters over the years, Wayne hones in on the reasons they should care from the obvious, omnipresent threat of ‘dead air’ to ‘loss of trust’ which is particularly motivating in recent years as we have seen state actors move to influence, not disrupt the normal course of life, in low-key, long-burn persistent attacks.

The talk hinges around the ‘AIC’ triad, comprising confidentiality, integrity and availability which are the three core aspects of data to protect. Integrity involves ensuring that the data are not altered either in transit or, indeed, in storage. Confidentiality revolves around ensuring that access control is maintained at all levels including physical, network-level and application live. Finally availability encompasses the fact that if the data isn’t available to the people who need it, the whole thing is pointless. Therefore supporting the availability side of the triangle includes thinking about redundancy and disaster recovery procedures.

Wayne, who is also the president of the Society of Broadcast Engineers, explains some of the attributes of a secure system which starts with security policies. These are the outer layer of any secure environment detailing how the many other layers of security will be managed and applied. Other aspects of a secure environment are appropriately layered and segmented network design, to limit what is available to anyone who does penetrate part of a system, access controls and logging.

After looking at the IETF and IEEE standards bodies, we see how the standard network models overlay neatly on the ATSC layered model with networking in the centre of them all. This leads in to a brief introduction to ‘IP’ in the sense of the the IP protocol on which are based TCP/IP and UDP/IP, between them central to most network communications around the world.

As we see how a small hole in defences can be slowly changed and enlarged allowing the attacker to move forward and create another hole in the next layer, Wayne talks about the types of security threats such malware, denial of service attacks and, of course, inside threats such as your employees themselves being complicit.

As the talk draws to a close we look at how this plays out in the real world talking through diagrams of broadcasters’ systems and how mitigations might play out on premise before talking cloud security. As the threat model in the cloud is different, Wayne explains the best practices to ensure safety and how these and the other security technologies used on the internet keep ATSC 3.0 secure including TLS secure certificate and the use of DNSSEC

The talk finishes with a look at security in the home whether that be with the myriad of consumer media consumption devices or items from the ‘internet of things’.

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Speaker

Wayne Pecena Wayne Pecena
Director of Engineering, KAMU TV/FM at Texas A&M University
President, Society of Broadcast Engineers AKA SBE

Video: Online Streaming Primer

A trip down memory lane for some, a great intro to the basics of streaming for others, this video from IET Media looks at the history of broadcasting and how that has moved over the years to online streaming posing the question whether, with so many people watching online, is that broad enough to now be considered broadcast?

The first of a series of talks from IET Media, the video starts by highlighting that the recording of video was only practical 20 years after the first television broadcasts then talks about how television has moved on to add colour, resolution and move to digital. The ability to record video is critical to almost all of our use of media today. Whilst film worked well as an archival medium, it didn’t work well, at scale, for recording of live broadcasts. So in the beginning, broadcasting from one, or a few, transmitters was all there was.

Russell Trafford-Jones, from IET Media, then discusses the advent of streaming from its predecessor as file-based music in portable players, through the rise of online radio and how this naturally evolved into the urge to stream video in much the same way.

Being a video from the IET video, Russell then looks at the technology behind getting video onto a network and over the internet. He talks about cutting the stream into chunks, i.e. small files, and how sending files can create a seamless stream of data. One key advantage of this method is Adaptive BitRate (ABR) meaning being able to change from one quality level, to another which typically means changing bitrate to adapt to changing network conditions.

Finishing by talking about the standards available for online streaming, this talk is a great introduction to streaming and an important part of anyone’s foundational understanding of broadcast and streaming.

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This video was produced by IET Media, a technical network within the IET which runs events, talks and webinars for networking and education within the broadcast industry. More information

Speakers

Russell Trafford-Jones Russell Trafford-Jones
Exec Member, IET Media
Manager, Support & Services, Techex
Editor, The Broadcast Knowledge

Video: Analog Luma – A History and Explanation of Video

There are many video fundamentals in today’s video looking at how we see light and how we can represent it in a video signal. Following on from last week’s look at analogue 525-line video we take a deeper dive in to light and colour.

The video starts by examining how white light can be split into colours, primaries, and how these can be re-combined in different amounts to create different colours. It then moves on to examining how the proportion of colours which create ‘white’ light isn’t as even as you might imagine. This allows us to understand how to create brighter and dimmer light which is called the luminance. We’re introduced to the CIE 2d and 3d colour graphs helping us to understand colour space and colour volume

Modern video, even if analogue, is acquired with red, green and blue as separate signals. This means if we want a grey-scale video signal, i.e. luminance only, we need to combine using the proportions discussed earlier. This biased version of luminance is what is called ‘luma’ explains the video from the Displaced Gamers YouTube Channel.

On top of human perception, much of the 20th century was dominated by CRT (Cathode Ray Tube) TVs, which don’t respond linearly to electrical voltage, meaning if you double the voltage, the brightness doesn’t necessary double. In order to compensate for that, ‘gamma correction’ is applied on acquisition so that playback on a CRT produces a linear response.

Pleasantly, an oscillator is wheeled out next looking at a real analogue video waveform demonstrating the shape of not only the sync pulses but the luminance waveform itself and how the on-screen rendition would be seen on a TV. The video then finishes with a brief look at colour addition NTSC, PAL, SECAM signals. A prelude, perhaps, to a future video.

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Speaker

Chris Kennedy Chris Kennedy
Displaced Gamers,YouTube Channel

Video: What is 525-Line Analog Video?

With an enjoyable retro feel, this accessible video on understanding how analogue video works is useful for those who have to work with SDI rasters, interlaced video, black and burst, subtitles and more. It’ll remind those of us who once knew, a few things since forgotten and is an enjoyable primer on the topic for anyone coming in fresh.

Displaced Gamers is a YouTube channel and their focus on video games is an enjoyable addition to this video which starts by explaining why analogue 525-line video is the same as 480i. Using a slow-motion video of a CRT (Cathode Ray Tube) TV, the video explains the interlacing technique and why consoles/computers would often use 240p.

We then move on to timing looking at the time spent drawing a line of video, 52.7 microseconds, and the need for horizontal and vertical blanking. Blanking periods, the video explains are there to cover the time that the CRT TV would spend moving the electron beam from one side of the TV to the other. As this was achieved by electromagnets, while these were changing their magnetic level, and hence the position of the beam, the beam would need to be turned off – blanked.

The importance of these housekeeping manoeuvres for older computers was that this was time they could use to perform calculations, free from the task of writing data in to the video buffer. But this was not just useful for computers, broadcasters could use some of the blanking to insert data – and they still do. We see in this video a VHS video played with the blanking clearly visible and the data lines flashing away.

For those who work with this technology still, for those who like history, for those who are intellectually curious and for those who like reminiscing, this is an enjoyable video and ideal for sharing with colleagues.

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Speaker

Chris Kennedy Chris Kennedy
Displaced Gamers,YouTube Channel