Modern Cryptography

AES, RSA, and Rijndael - if these mean nothing to you then you're clearly not interested in cryptography. If that's the case why are you reading this blog?!
Anyhow - if your an engineer of any kind in this modern world then there are certain things you should have at least a passing familiarity with - how TCP/IP works is another one.
The best primer I've ever come across is episode 31-37 of Steve Gibson's Security Now podcast go from symmetric stream ciphers (the Enigma Machine being a prime example) through to current state-of-the-art methods. It's very listenable and so if you have a spare eight hours (ideal on the commute) you should check out those podcasts from a couple of years ago - link in the title.

The Shield, end of season

Episode 13 of Season 7 was one of the best and most dramatic hours of television I've ever seen. I've been following it since the first year and it is the only cop show that has never lost it's dramatic tension and has never indulged in 'character development' episodes. Compared to the various CSI variants (which I like for different reasons) it shines.

Flobots

I am so far behind what the kids are listening to but after hearing this blaring out of my eldest two's bedrooms and iPods I thought I'd check it out.
I'd had a vague interest in some of the more intelligent hip-hop from the early nineties - Jungle Brother, Tribe called Quest, De La Soul etc. but most modern hip-hop leaves me cold. It seems like all the things I ranted about as a teenager - materialism, violence, mysogyny, and hatred are all required elements for the modern rapper. I found this in a paper by Darren Rhym of The Department of English of The University of Georgia;

In the end, this whole argument boils down to the fact that misogyny is ingrained into our culture and we allow it. We buy CDs and go to concerts where gangsta rappers call black women "bitches" and "hos." It is not just black women who are victimized. Since gangsta rappers disrespect our mothers, sisters, and daughters, every black man is a victim.

Excuses -- "I like the beat," "I don't listen to the words," and "They are only referring to certain types of women" -- are not acceptable. When gangsta rappers disrespect men and women and preach violence and hate to us, we must reject their messages. We cannot buy their CDs, albums, or tapes, or attend their concerts, or appear in their videos, or even support record labels or radio or television stations that advocate gangsta rap in any way. Malcolm X used to preach about the ills of airing "dirty laundry," and that is what gangsta rappers do when they disrespect black women in rap songs.

Rap is not just music; it is our African-American culture. It is the way we blacks perceive ourselves, and the way we are perceived by the world. The content of gangsta rap music in its current form is unacceptable. It cannot and should not be tolerated by anyone.

He should check out Flobots album - not only is it intelligent non-hate-filled lyrics but they are musically an order of magnitude more interesting that Dr Dre et al. Real drums with guitars and even jazz-influenced arrangements. Currently what's on my MP3 player.

Jailbreaking / unlocking iPhone for v2.2 f/ware

If you have a first gen iPhone and it's at v2.02 (at least) you can proceed to doing an iTunes upgrade without fear - the radio firmware isn't changed but apparently battery life and stability are improved (so Joe, my fifteen year-old tells me!)

Friday thoughts

I was out at Pinewood Studios on Wednesday doing some final work in a grading theater - Brian kindly brought me a good cup of brewed coffee (it was around 11:30am and it was my fifth cup of brewed coffee) and it left me feeling very jittery! Consequently I've decided to cut down on the coffee and I only drank tea yesterday - I felt a lot better by the end of the day and I have a feeling I slept better. The problem is I like coffee so much!

Parallels version four is out and I installed it yesterday - very good, a bit faster on the screen handling and startup/close-down of the virtual machine (XP SP3 on Leopard) was a lot faster. Simon didn't find it so good though on his MacBook. It tried to convert the v.3 VM but it failed - however, re-creating a BootCamp VM is trivial.

Good TV - There seems to be a load of good tele at the moment - Lead Balloon (Jack Dee's sitcom) - currently BBC2 are showing season 3 (it used to be a BBC4 show). Outnumbered - BBC1's (again, from BBC4) is hilarious. Little Dorrit - the BBC does a superb job of Dickens again. Star Wars:Clone Wars the animated series - Cartoon Network are showing the latest itteration of that franchise. Mythbusters - fantastic family tele. The Shield - series 7 on FX is the best yet and very exciting.

10mBit broadband - I recently got upgraded and although Virgin Media are hopeless when things go wrong I'm loving being able to torrent an episode of something that aired in the US last night at 3 minutes per half-hour of TV!

I wish I had the nerve...!

Inductive loads and power correction

The power factor of an AC electric power system is defined as the ratio of the real power to the apparent power, and is a number between 0 and 1 (frequently expressed as a percentage, e.g. 0.5 pf = 50% pf). Real power is the capacity of the circuit for performing work in a particular time. Apparent power is the product of the current and voltage of the circuit. Due to energy stored in the load and returned to the source, or due to a non-linear load that distorts the wave shape of the current drawn from the source, the apparent power can be greater than the real power.
In an electric power system, a load with low power factor draws more current than a load with a high power factor, for the same amount of useful power transferred. The higher currents increase the energy lost in the distribution system, and require larger wires and other equipment. Because of the costs of larger equipment and wasted energy, electrical utilities will usually charge a higher cost to industrial or commercial customers where there is a low power factor.

Thinking about power-factors all came from various discussions with the wiremen and engineers whilst working on site over the last couple of weeks - In the case of the kind of builds we do we always ask customers to provide a power supply with inductive rated breakers. This is from our standard Scope Of Works document;

The equipment cabinets will be wired with 14-way IEC mains distribution units. Every circuit is fuse-protected and the mains input is terminated in a 16A C-Form connector (AKA a ‘Commando’ plug) – Root6 requirement is that the client’s electrician provides a separate spur connection for each bay and all feeds are provided via a D-rated 16A MCB. We recommend the area is protected by an Earth Leakage Breaker. We will test all mains installs in accordance with edition 4 of the 16th ed. IEE regulations using a standard suite of PAT tests.

We've fallen foul of a customer who didn't pass this on to their electrician and we've been battling with B-Rated (i.e. resistive-load) breakers not being able to hold an 16A circuit to a bay full of switch-mode power-supplies (i.e. all modern broadcast equipment!). When a strongly inductive load such as a switch-mode/resonant-mode power supply is switched on input surge current which may be several times larger than the steady current flows. It's also why the mains in Soho is nearly a square-wave - all those odd-order harmonics being dumped back out onto the incoming supply.

The idiots have won!

Charlie Brooker's Nathan Barley is still one of the funniest things ever on TV - I know 'cause I deal with a lot of those people - Meeja Fools!

Once the idiots were just the fools gaping in through the windows, now they have entered the building. You can hear them everywhere, they use the word cool, it is their favourite word, the idiot doesn't think about what he is saying, thinking is rubbish and rubbish isn't cool...... Stuff and shit is cool. The idiots are self regarding, consumer slaves. Oblivious to the paradox of their uniform individuality, they sculpt their hair to casual perfection, they wear their waist bands below their balls, and they babble in to handheld twit machines about that cool email of a woman being bummed by a wolf.... their cool friend made it, he’s an idiot too. Welcome to the age of stupidity, hail the rise of the idiot.

Those two fine examples of humanity - Jonathon Ross and the other guy are in trouble for reverting to type on Radio 2. But, imagine my suprise when I was in the newsagents to buy a bag of crisps and I saw this cover of a lads mag - the young woman in the centre of the whole debacle with her kit off - the idiots have won!

Fridge-freezer mains earth defrosting connundrum!

I have an upright fridge-freezer in my kitchen and about a year ago I moved it to clean underneath. Since then every month I've had to defrost it (despite it being a frost-free model) and was getting ready to maybe replace it. However, three months ago I noticed that the extension cable that powers it (from a socket in the lader) had been tugged (I assume when I moved it out to clean) and on further inspection the mains earth had come out in the trailing MK13 socket on the end of the extension. I re-wired it and since then the thing hasn't frosted up once!
I'm at a loss - how does the presence (or not) of a mains safety earth cause this behavior? What about those countries that don't have an earth?

If you've got a thought then I love to hear it - have a party in the comments!

Trying to get enthused!

Despite my first weekend since August when I did no work between Friday tea time and Monday I don't feel very enthusiastic about broadcast engineering - I hoped I'd be refreshed and full of beans but I'm a bit flat. Hopefully the following lecture at the IET will perk me up!

The Beijing games were the biggest and best ever. Paul Mason of BBC Television will describe the technical challenges of delivering multi-media coverage from dozens of venues from the other side of the world. He will cover the planning and technical operation of the Games, including both the Host Broadcaster and BBC operations

I can take guests so if you want to go let me know.

New York tests analogue shut-off

New York City over-the-air analog TV stations went dark for two minutes yesterday. The prescheduled test gave a temporary taste of what's planned when the stations permanently pull the analog plug on February 17, 2009.

My DVB-T television (which runs Linux!) needed a first birthday the other day (the DVB decoder temporarily went AWOL) and so for a day I was watching composite analogue signals from Crystal Palace. I have to say that I now find MPEG2 compression artifacts less objectionable that multi-path/PAL-decoder errors. The analogue switch-off here in Blighty can't come quick enough!
Now then, when's that DVB-T2 HD over H.264 switch-over coming?!

Eyeheight legalisers parameter bugs

I came across this a couple of years ago - if you recall the Rec103 preset the ringing perfromace is wrong!
Here is the email I got from their tech support back in September 2006 and the one I installed a couple of days ago is still suffering!

...this is a software bug which we have just noticed and are now working on. We should have a fix within the next few weeks.

In the interim you could enter the values for the EBU settings you require manually. You could even store these values into memories and label them as explained in....

http://www.eyeheight.com/manuals/systemHardware/evolutionDT_platform_user_manual.pdf

Here are the values for the various presets....

Memory 1 Legaliser On 0% - 100%

Memory 2 1. Set High Clip = 105%

EBU 103, 2. Set Low Clip = -5%

Tight 3. Set Ring Suppression to "MANUAL"

4. Set High Ring Threshold = 103%

5. Set Low Ring Threshold = -1%

Memory 3 1. Set High Clip = 103%

EBU 103, 2. Set Low Clip = -3%

Optim' 3. Set Ring Suspression to "MANUAL"

4. Set High Ring Threshold = 101%

5. Set Low Ring Threshold = 0

Memory 4 Bypass / Legaliser Off.

....hope this helps and we will contact you with the software up-date files which you can flash into your legaliser using the RS232 port of a PC.

Netvue - business class IP TV system

I went to a very impressive demo at Sony BMG today - they have an Exterity-based office IP-TV system as provided/configured/integrated by NetVue. They seemed to have really got it right. The system is based on IGMP multicast over IP which relies on IGMP-compliant switches (think Cisco 3750 or equivelent HP ProCurve). Essentially it means that only the streams that are being watched are present on the network and then only the data is present on those segments with active clients.
Set-top boxes are tiny and around the £250 mark. The PC client comes in at £35 per seat.
What I found to be the really clever side of it was the TV gateway which takes DVB-T multiplexes and strips out all the transport streams and makes them available. So, with their 1u chasis you can expose all six FreeView Muxes (55 stations?) on the network for around £8k - to build an RF-system with similar abilities would cost many times this and the pictures would look awful (I know - I've built a few!). If you need to hang a video device (Sky STB, DVD player, etc.) their STB & PC client can both back-propagate IR control.
As mentioned - I kept getting the feeling that 'they've done this right' - it's a very complete/robust solution. I like the idea that when they can avoid it they don't re-encode the video and assume the clients can replay MPEG-2 transport streams (or in the case of the HD STB H.264 transport streams).

I can't wait to spec one of these!

Lorenz Cipher & Collosus

I went to a superb lecture at my institute - The IET - all about the German Lorenz cipher from the war and the Colossus machine built at Bletchley to crack that code. Tony Sale is a very engaging speaker and clearly a very competent engineer. He is the proprietor of the Computing Museum at Bletchley and has (for the last ten years!) been re-building a working Mk2 Colossus.
The Colossus computers were used to help decipher teleprinter messages which had been encrypted using the Lorenz SZ40/42 machine — British codebreakers referred to encrypted German teleprinter traffic as "Fish" and called the SZ40/42 machine and its traffic "Tunny". Colossus compared two data streams, counting each match based on a programmable Boolean function. The encrypted message was read at high speed from a paper tape. The other stream was generated internally, and was an electronic simulation of the Lorenz machine at various trial settings. If the match count for a setting was above a certain threshold, it would be output on an electric typewriter.

I did take copious notes, but Tony's website is excellent and Wikipedia has good articles on both the Lorenz Cipher, which (like the Enigma) is a symmetric stream cipher, and the Colossus computer.

Tony set a challenge a year ago to receive and break a Lorenz transmission and the German engineer who won was using a 1.4 GHz laptop which, running his own code, took less than a minute to find the settings for all 12 wheels. The German codebreaker said: “My laptop digested ciphertext at a speed of 1.2 million characters per second – 240 times faster than Colossus. If you scale the CPU frequency by Moore's Law, you get an equivalent clock of 5.8 MHz for Colossus. That is a remarkable speed for a computer built in 1944."

Whichever way you think about it the codebreakers at Bletchley shortened the war by months or even years and so can be considered the real heroes of WW2.

DivXLand Media Subtitler

DivXLand Media Subtitler allows the user to manually subtitle movies and videos while viewing the applied captions on the fly. It includes some features like automatic timing limit, easy caption edition, and offers 2 modes for applying of captions.

My kids like anime and as all true snobs they are very dismissive of people who watch English dubs. However - they don't speak Japanese and so a way of checking/editing subtitles before they are burnt into the video (Using VirtualDub - what else?!) is needed.

Seasick Steve

I've just downloaded his album (from 7Digital - all MP3!) and I'm loving it!

TriCaster - very impressive

Earlier in the year I banged on about the TriCaster after I had a demo. We've just finished an install at the College of Law using it as the centre-piece of their little three camera studio and I am even more impressed than I was! Driving the virtual environment is so easy and it really does perform well. Having a selection of four shots per camera (you set the shot for the close-up and then each camera is available as the close-up, MCU, twp-shot and long-shot) with an environment that tracks perfectly is a revelation. The in-set virtual monitors work as well. The perspective and reflections on desks etc are all very convincing and once you get past the fact that all the virtual sets look like CNN or ESPN you can really produce some expensive looking tele.

I hope Root6 pick this up as a product because there is nothing to match it sub £100k.

Interesting

I picked up this flyer in Borders yesterday - it's the first time I've seen this in any kind of retail outlet, let alone a book shop;

Customers can choose from items in an e-catalogue or an instore printed version. Once purchased from the console, the software is pressed onto a disc with a special inlay card and user manual. The entire process is planned to only take a few minutes.

I got a GoogleWhack!

Whilst searching for details of some monitors I have to calibrate later this week!

Adeona - stolen laptop tracker

I installed Adeona on my MacBook Pro over a week ago and promptly forgot I had it on there - it consumes little processor time and you're unaware of it. What is does is continually send photos from the iSight camera and any useful info - IP, nearby DNS servers, router names etc - basically anything to help physically locate a stolen computer. Best of all it's open source and the OpenDHT storage it uploads to is 256-bit encrypted.