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Comment Still False (Score 1) 371

Jane Q, you've got some good points but it's still a bit mixed up. IAAME (I am a microwave engineer)

1/ A rectenna the size of New Mexico would actually be very inefficient. Narrow beams are the best way to efficiently transmit microwave signals.

2/ Correct, microwaves are not ionising radiation. Microwaves just heat you up and cook you from the inside out, they don't cause mutations and cancer like the other sort of radiation.

3/ Correct, 100 mW from the transmitter is not necessarily 50 mW at the target.... unless the target is close enough of course :) But microwave propagation follows an inverse square law, so double the separation and exposure drops to one fourth.

4/ Radiation from cellphones and from WiFi are both in the microwave bands. Low bands, sure, but definitely microwaves.

5/ 50 mW might sound big but it's nothing. Check out Microwaves101 for more about exposure levels: http://microwaves101.com/encyclopedia/biological.cfm

For what it's worth, I think this SPSS is a crock. Too expensive, maintenance sucks, and there are too many other options that are lower risk and lower cost.

Privacy

Submission + - Porn "Random Breath Tests" for PCs (news.com.au)

Gwaihir the Windlord writes: A university in Western Australia has started beta testing a tool that's described as "a random breath test" to scan computers for illicit images. According to this article it's a clean bootable linux environment. Since it doesn't write to the hard drive, the evidence is acceptable in court, at least in Australia anyway. They're also working on versions to search for financial documents in fraud squad cases, or to search for terrorist keywords.
Other than skimming off the dumb ones, does anyone really expect this to make a difference?

Privacy

Submission + - China to photograph all internet cafe customers (news.com.au)

Gwaihir the Windlord writes: Not only is the Great Firewall of China back up and running, but now if you visit an internet cafe, your photo will be taken and your identity card scanned. And the friendly officers of the Cultural Law Enforcement Taskforce make those details available at any other cafe. So much for the new levels of openness and transparency that the Olympics were supposed to usher in.

Comment Re:Sentries and pattern matching (Score 1) 110

The problem is not so much the way the sentry's brain function as the way the PHB's brain functions. Too many amateurs either have no security, or they think that the one or two layers they've got is sufficient. Even worse, they might have a decent security system in place, but they compromise it because they can't be bothered doing their part to make it work.

The first thing you have to ask is: what do you want to make secure? Is it a PC, a site, an aircraft? There's not much point having layers of sentries, keys, and passwords if your "secure" computer is hooked up to the net. Even with firewalls, if it's supposed to be secure, it shouldn't be online in the first place. If the site's meant to be secure, then it helps to only have one gate that people enter and exit through. Another mechanism is for employees to keep their ID cards clearly visible and to challenge any unfamiliar person walking around unescorted. When it comes to securing aircraft, the most sensible option is in the article: put in a half-way decent door! Sure it weighs a few kilo extra, but not so much that it will cause a problem, given the normal distribution of passenger weights.

Technology can help human security - some of the better airport X-ray machines will highlight different items on screen - organic items in one colour, metallic in another colour, so that the operator's eye is drawn to the suspect item.

Your idea of filtering the alerts so that the operator only sees the top 10 is nice, but I think it suffers from a fatal flaw. Yes, 1000 alerts per hour will be ignored, or else it will overwhelm the operator, which is no better. Yes, designing a proper system and calibrating it to reliably remove false alerts is very expensive, although it shouldn't cause a false sense of security if it's used correctly. But aren't you proposing the exact same thing by generating 1000 alerts but only flagging the 10 (or even 100) most suspicious? You're filtering the results before giving them to the user, and unless they have a lot of time, or are very keen, they're not going to check out any more than the 10 that get shown to them. Also, what's the point of generating that many alerts if most of them are being ignored or filtered? On the one hand, your system might be too sensitive, in which case you can hopefully calibrate it to a better response rate. On the other hand, someone might be expecting to evaluate all the alerts later, but in any site big enough to generate 1000 alerts per hour, chances are that if they slip through immediately, it will be too late to do anything once the alerts are finally reviewed.

Ultimately, the best security system is one that's designed specifically for your application, that uses a range of different techniques (hence the term distributed), where the limitations of each method are well known, and there is at least one other method to cover a gap if something gets beaten. One mans perfect security system might be overkill for someone else, and an insecure joke to another.

Just my $0.02

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