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Comment Give them something to do! (Score 4, Funny) 334 334

If you can be reasonably certain that your laptop will be seized and searched then you might as well have some fun.

1) Get a brand new hard disk.
2) Load OS and common software.
3) Apply full disk encryption if possible supported by hardware TPM.
4) Fill disk with pointless and uninteresting files (kitten videos, boring sales brochures for catering equipment, vast datasheets for common microprocessors etc etc).
5) Generate a little script which goes through and encrypts each file with a different randomly generated key (obviously run scipt from external media which you don't take with you).
6) For added fun, install a publicly available unencrypted movie (perhaps one you have made if you happen to be a film maker, otherwise something like Dumbo) and then use steganography to hide something inoccuous in it (e.g. the complete works of Shakespear).
7) Don't expect to ever get the laptop back.

Obviously this will take a fair bit of work, but that will be nothing compared with the huge effort expended by your tormentors in trying to work out what it all means!!

Comment Let's wait for some actual details (Score 1) 174 174

It is perhaps worth remembering that we still have no real idea exactly what this proposed legislation is going to say other than a fairly clear indication that ISPs will be required to keep some sort of record of web sites visited. There are also a couple of other reasons to think positively:
1) The recent government sponsored report into this matter came out very clearly against suggestions that encryption should be controlled. But, governments are good at ignoring reports which don't say what they want even when they asked for them in the first place.
2) The goverment has a very small majority and a number of their more rebelious members are hot on personal liberty and privacy. Not a huge number, but enough to cause a problem. The majority opposition labour party may well have some sympathy with the aims of the legislation but would far rather have the political gain of seeing the goverment lose. Before the recent election the now governing conservative party were keen on the idea of withdrawing the UK from the European Convention on Human Rights. Now they are in government the idea has been quietly moved well down the priority list presumably because of the same liberty loving trouble makers in their ranks. The bottom line is that the government may well remove some more controversial ideas from their proposal to maximise the chances of trouble free progress for what is left.

Comment Perhaps this is a good thing? (Score 4, Insightful) 113 113

Just suppose that following Snowden a large percentage of the population decided to significantly increase the security of the internet use. This would force the NSA et al to increase power of their automated collection systems to compensate and those of us already taking enhanced security measures would lose out. If the populous does nothing then the NSA can just continue as they were.
Of course, one could argue that this lack of popular action simply makes security concious users stand out in the eyes of the NSA and attracts special attention. But perhaps this is also a good thing. Allow me to explain:
I start with the precept that the NSA will be able to gain access to practically everything I do online (and probably offline) no matter what I do. Given this, I would far rather be a special case. Imagine somone at NSA HQ clicking the "Collect and analyse all internet traffic from the UK" icon. Their computers hoover up some vast number of terabytes including mine and finds little of interest. The operative takes another bite from his apple and clicks the next icon "Collect and analyse all.....". My data has been spied on and I am iritated, but unless he finds a rotten bit of apple he isn't.
Now imagine that my security is rather better than most. The operative clicks the icon, but gets an error saying "Data from Huskydog not available". Gosh, thinks the operative, someone hiding their information, I must have stumbled upon an Al-Qaeda sleeper cell. He puts down his apple and starts to dig deeper. Eventually, after some time and effort he breaks in and ..... Nothing! (or at least nothing interesting to the NSA). He has wasted considerable time, his apple has gone brown and he has nothing to show for it. I am just as iritated as before, but now he is iritated as well.
So, given that we wish to iritate the NSA (and that is probably we worst we can hope to do to them) perhaps the best solution is to have a significant number of special cases which stand out from the easy to access heard and thus require special time consuming efforts to spy on but with nothing to show for it in the end.

Comment Physical Security (Score 1) 342 342

The article states that the room could "only be entered by two people at a time". What does that mean exactly? Was it a very small room with only enough room for two people (or three if they're European :-) ). Or does it mean that none-one was allowed in on their own? In this latter rather more usefully secure case what process was used to enforce this rule? Just the CCTV?

Surely, systems like this need to be in rooms with locks which require multiple keys to open so that a lone individual can't get in no matter who they are? Perhaps a timed lock which can only be opened during normal working hours when there are plenty of people around would also be a good idea.

Comment What a wonderful unit! (Score 5, Funny) 332 332

At first I thought that the 'Acre-Foot' sounded like a joke unit, but obviously it is the amount of water that one hundred and twelve horses need to drink if they are each to plough eight hundred furlongs of furrow in a fortnight!! Honestly, you Americans just crack me up with your wacky units. So much more fun than being stuck with boring old litres!

Comment Re:NOT Invisibility Cloak: RADAR Cloak (Score 1) 197 197

The key issue is how little of the radio waves are reflected.

Indeed, I couldn't agree more, and this is a property which rarely seems to be mentioned in meta-material discussions. Supposing that such a material passed 95% of the energy undisturbed and only reflected 5%. I think that this would rightly be regarded as an excellent technical achievement, and after all some glass isn't that good, but it would seem to be of limited military value. As we know from the radar equation's R^4 term, this will only reduce detection range by a little more than 50%, and you can easily buy commercial radar absorbing materials which will do much better than this.

Of course, your absorbing/transmitting solution also has to meet many other criteria. It needs to work over a wide range of frequencies, polarisations and angles; be rugged enough to survive on the outside of a military vehicle without needing maintenance every five minutes; not be so heavy that your aeroplane can't take off and most of all, be affordable (I appreciate that military affordability is not the same as normal affordability, but never the less budgets are much tighter these days). Of course, progress is probably being made in all these area's but my feeling is that there is still a long way to go.

My other big problem with meta-materials is seeing how they can possibly be applied in real life. As I see it, they are basically being used to make a sort of cunning lens which diffracts the wavefront around the object to be concealed. Sadly, the geometry of the situation seems to result in devices which have a high degree of symmetry (for example, cylinders). I can imagine how this might be extended to a sphere (great if we need stealthy cannon balls) or maybe even a prolate spheroid (which perhaps we could fashion into some sort of missile), but to deal with the complex shape of an aircraft in such a way that the different parts of the wavefront passing around different parts of the wings and fuselage all add up correctly in phase over a useful range of angles seems to me to be an extremely difficult problem.

Still, I am not going to sit here and say that it can't be done. The people working on these problems are no doubt very brainy and may come up with a practical solution, but presumably the paint and shape solution is also being advanced and it is my feeling that this older simpler technology is going to stay ahead for a considerable period of time.

Comment Re:NOT Invisibility Cloak: RADAR Cloak (Score 4, Insightful) 197 197

Sigh, here we go again! Radars and optical vision do not work in remotely the same way. Creating invisibility in the two different realms is a completely different problem.

In most vision situations there are two critical factors which don't occur in the great majority of radars. The first is illumination of the target from angles other than the viewing angle (OK, there are bistatic radars, but they are not common) and the other is a background which is illuminated. Try to think about this for just a few moments. Why can't we all make ourselves invisible just by wearing matt black clothing? Well, obviously because we will stand out against the background unless we happen to be standing in front of black wall or wandering around in a coal mine. The whole point of the fictional 'invisibility cloak' is that it works in all circumstances. We can already be invisible in certain carefully controlled environments, that after all is what camouflage is all about.

But, a radar is rather like wandering about in the above mentioned coal mine, or perhaps a dark forest with a miner's lamp fixed to your head. The background is basically black and the illumination comes from the viewing direction. In this scenario, someone dress entirely in black would be effectively invisible. And that is the key point to grasp. In the world or radar we can achieve invisibility simply by making sufficiently 'black' 'paint'. The weird ability of these meta-materials to allow the illumination to pass through the target un-disturbed is of no benefit. Since we don't have a receiver on the other side of the target to detect this energy it isn't relevant. Now, sure, we can all dream up complex bistatic radars which rely on the obscuration of the signal to detect the target, but I remain to be convinced that such a thing can be made sufficiently versatile to be useful.

Can I stress that I am not suggesting the these meta-materials don't have an application in the world of radar. They seem to me to be particularly useful where one wants to remove a fixed object which obscures the view of your radar. For example, consider a radar on a ship. It may well find that in some directions its view is obscured by other parts of the superstructure. If the could cover these other bits of the ship with meta-materials such that the radar pulses could pass 'through' and back again undisturbed, then our radar's field of view would be increased. Such an application would work perfectly well with even the relatively narrow band materials presented previously.

Like punning, programming is a play on words.

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