One of the main features selling M$ Word is easy to use versioning. So, imagine people at your place of work using a Wiki instead of emailing each other 20MB binary files and overwrite each others changes all day long.
A collaborative editor might be a better replacement than a wiki. With a collaborative editor two or more people can have the same document open on different computers at the same time. When someone types words into the doucment they appear on other peoples screens in real time. With a wiki you can have the problem of two people making changes at the same time and whoever saves last overwrites other peoples changes.
Moonedit has the complete past history of the document, every keystroke.You can go back to every point in the history of the doucment and even see when someone made a type and backspaced.
That's not a problem with a collaborative editor where people are on the same LAN and are allways connected. You still have a version control problem if people work on documents offline.
I'v been using moonedit for about a year, mainly so I can have my todo list open on several computers at once. I could use a wiki but I'd have to remember to press same every time I added a two word note like "buy carrots". There are several other free collaborative editors but I havn't bothered to try them yet.
Moonedit just does text, no bold/underline/italic/fonts. I don't know off hand if gobby/ACE/subethaedit/etc have wordprocessor -like features.
http://science.howstuffworks.com/bunker-buster.htm/printable "When the bomb hits the earth, it is like a massive nail shot from a nail gun. In tests, the GBU-28 has penetrated 100 feet (30.5 meters) of earth or 20 feet (6 meters) of concrete."
Actually I think that is evidence in favour of my point. In most places you will have hit rock 150feet down.
Here in the real world, the one in which people actually understand electromagnetic propagation through a medium, MIRACL, a megawatt-class deuterium-fluoride chemical laser, successfully disabled a satellite in orbit almost 10 years ago.
Wrong. That test failed. It did not work.
See the wikipedia entry on SDI (assuming some stupid troll hasn't just edited it).
>From what I remember of the old SDI program, a high power laser would be used to ionize air thereby creating a path for a particle beam.
I don't think that idea was ever taken seriously by anyone who knew anything about physics. Despite wasting tens of billions of dollars on it SDI was still tens of orders of magnitude short of the energy need to destroy missiles with space based lasers, never mind with 30Km of air in the way.
You can't ionise the air to the edge of the atmosphere, you will just pump energy into a cloud of plasma just above the laser.
>This new program [...] may not destroy the satellite but disable it, e.g. imaging sensors can only take so much photonic energy before they are burned out.
Light is scattered by the air. Even a beam of light consisting of perfectly parallel rays digerges due to equal charges repelling.
It may be possible to temporarily blind an optical sensor if it is pointed at you which a high-res spy-in-the-sky won't be but I don't believe it's possible to permanently damage a sensor from the ground. The numbers for the path loss, the amount of energy you need to damage a sensor and the beam strengh you can generate before you ionise the air add up to it not working.
This is impossible. A laser beam is a very high frequency electromagnetic wave. It is a electric field and a magnetic field moving together.
The breakdown voltage of air is about 2000V per millimeter.
With a powerfull laser in a lab, which is about fifty orders of magnitude too weak to do anything to a satellite, you can get sparks in mid air due to the air breaking down because of the high voltage of the electric part of the electromagnetic wave.
You cannot generate a laser beam powerfull enough to destroy a satellite from the ground. IF you tried you would just make a lot of plasma in the air above your laser. Focusing lots of little lasers on a satellite would require far more lasers than could be practically built. I suspect these storys are planted in the media to worry unfriendly countrys, just like the star wars program that never had a chance of working or the rediculous story I saw in a newspaper a couple of years ago about missiles that can burrow into the ground and destroy a shelter 150feet down.
I also think it's a sad reflection on the state of slashdot that this story is up to 150 comments and I'm the first to point this out. I'm going to go and bash my head on a wall unitl I come to my senses and stop even reading alterslash.
I happen to be working on a box thats about to get reinstalled so I broke my usually rule of allways monitoring what new software does in a virtual machine first.
On slackware 9.1 I get this
root@obfusticated:~#./spoofer >> Spoofing Tester v0.4 >> Rob Beverly >> More information: http://spoofer.csail.mit.edu/ >> >> Source 5 non-spoofed packets... Broken pipe
tracert shows a load of packets between here and fyodor.emailtester.net (18.26.0.235)
strace shows it stopping at write(3, "DISTANCE LINUX 4\n", 17) = -1 EPIPE (Broken pipe)
I think you'd agree that buying a treasury for 63 cents on the dollar represents a pretty good investment
Actually I believe the peak oil theory. Combined with the inevitable long term consequences of the USA's national debt passing nine trillion dollars I think that any ten year investment denominated in US dollars is horrifyingly risky. US treasury bonds are still massively overvalued at 63cents per dollar.
Metamachine, the company that made edonkey, tried a system called transmission films. They put films on the ed2k network (edonkey, emule, shareazza) in windows media format with DRM. The idea was that people would pay to watch the films. They had a few classic horror films and other stuff.
It appears to have been a complete failure. They took the link to transmission films off the edonkey homepage in early 2005 and the site has been down every time I'v looked since then. I tried downloading one of the films a few years ago when the site was still up to see how it worked. It took about two months because nobody was resharing the DRMed files.
It seems to me that if commercial p2p downloads don't work on the ed2k network with several million users and a link from the edonkey homepage then the idea that individuals could make any money by uploading or recommending content is laughable.
People using p2p networks simply do not want to pay.
I'm not keen on writeboard because it means leaving my information in the hands of some random website. Some documents are private and I'm not confident any dot com will be around for the long term. I'v seen a few webmail services disappear overnight along with the email I had on them.
Moonedit and gobby are worth a look. They keep the files on your machine where they can be automatically backed up and if the software falls over you have access to sort it out yourself.
I work on smart cards, including biometric passports. In this field, no one in their right mind would use RFID tags for passports, or anything requiring security. Ever.
The problem here seems to be terminology (and clueless moderators).
You are incorrectly assuming that "RFID" means a simple tag with no crypto.
RFID is a generic term for any device that uses RF and identifys it's presence or absense. A resonant circuit without a chip that is used to tag library books is an RFID. A contactless smartcard that uses cryptography to make it harder to clone is an RFID.
people then make the assumption that anything contactless is RFID That is a correct assumption.
and thus insecure. This is an incorrect assumption, however as Shamir has shown it is early days for RFID security.
I was similarly baffled. I work with DoD to develop and implement RFID solutions for transportation and asset accountability, and I've never heard of anyone trying to encrypt the data on an RFID tag.
Sadly I am not surprised by someone who works on a government IT project not knowing what he is talking about. The card systems currently on the market for opening doors generally use challenge-response authentication.
I'm told that the plan is for the UK RFID passports to use crypto. (and yes a contactless smartcard is an RFID.)
That cloning device only works on cheap RFID's that don't do cryptographic authentication. This is not the first time this has been done. http://www.cl.cam.ac.uk/~gh275/relay.pdf
The method Shamir talked about is a little more interesting because the cards are leaking information wbout what they are doing internally. It is possible that a more detailed examination of the power consumption may reveal other detail of what the card is doing as well as when it things it has receive a bad bit.
Power analysis has been a known attack on smartcards for a long time. A few cards were vulnerable to an attacker looking for increase current draw just after a PIN/password attempt when the card tried to increment a count of the number of failures, cut the power when it tries to write to the fail count and you could attempt a brute force attack. I believe the most obvious way around the problem, to decrement the counter before checking the PIN and increment it after if the check passed, is patented.
It would be interesting to see if any RFID cards have that flaw.
1: Your new service provider just puts your existing, personally owned (or given to you for free by the naming authority) IPv6 addresses into their routing tables. Everyone that had your number before still finds you at the same place.
This will not happen for cable/adsl users. There are already problems with the size of the internet routing tables, it's not practical to have a routing table entry in the big routers that connect isp's togethre for every geek at home.
The ip6 rfc actaully says that the routing is heirarchial and that ip6 addreses should not be considered to be property and can be renumbered when necessary.
"At one watt, we can cram 7.4 bits into one cycle of a sine wave.
Not quite. It suggests they can cram 7.4 bits into a 1Hz wide channel. For example in theory you could descide to represent data using a carrier which at any instant in time can be at one of 256 different power levels. That gives you eight bits per symbol. To keep the frequency components of the signal within a 1HZ channel you have to change the power level slowly which liits the symbol rate. For this to work you need the signal to noise ratio to be high enough that you can tell the difference between the different carrier levels in the time available. If you make the symbols longer you have more time to average out the noise.
Shannon's law gives the maximum amount of data that can be sent through a channel with a paticular bandwidth and s/n ratio.
No, DR DOS was originally owned by Digital Research. These were the guys that IBM originally was going to buy their dos from, but their CEO at the time blew off IBM and went sailing instead(!). He was fired soon thereafter.
That was Gary Kildall. If you are going to repeat a computer industry myth at least get it right. He was out flying his aeroplane not sailing and he wasn't fired, he later sold the company to Novell for 120 million.
About three years ago a usenet death penalty was issued against Telewest. Before it came into force they stopped all messages spreading out from their main newsserver and began scanning their customers for open newsservers and open proxys.
A german company that I'v forgotten the name of reccently won a two year legal battle to sell box's that do advert skipping. I'd like to see it in the hands of the European masses soon as it will be hard to pass laws to ban it if lots of people start using it.
A PVR could do collabortive advert skipping. If advert skipping becomes popular then the TV companys will make it as hard as possible to automatically skip adverts. Some TV stations currently put out a fraction of a second of black at the start of an ad break or other signals that can be detected by a machine. We probably can't rely on them allways being there. The alternative is to connect PVR's to the internet. When ten people are watching a channel it would only take one to press a button at the start of and end of an ad break and everyone's PVR could skip the ads. It would require a bit of intelligence to deal with people pressing the button at the wrong moment, for example if twenty people are watching a channel you might require two people to press the skip button before it causes everyones viewing to skip plus a rating system to detect deliberate misuse or people who just press the wrong button too often.
As I understand it, just before this latest terrorism mess started up over there, they were willing to give in to almost all of the Palistinian demands.
The fighting between zionists and arabs has been going on since before the state of Israel came into being.
The Israel's gave the Palestinian's self rule in Gaza and Jericho in 1994 after a peace agreement with the intention of a seperate state after five years. The Palestinian's continued attacking the Israel's.
If the US didn't support Isreal there would be more chaos. The Israel's have nuclear weapons and will probably use them if it looks like Isreals will be overrun. The USA and Europe don't want millions of Jewish refugees seeking asylum.
The muslims are generally intolerant of other religions and oppress women.
a completely harmless msn plugin is set for deletetion Actually one of my jobs this weekend is to look at a machine that is reportedly running very slowly and has a click-here-to-buy-stuff taskbar at the bottom of the screen all the time since someone clicked YES on the "messenger plus install new version" nag box.
EDonkey uses SHA1 hashes to uniquely identify files No, it uses a custom md4 based hash. For files larger than 9.5MB the ed2k hash is a hash of the hashes of 9.5MB chunks of the file. This is so that the client can get a list of hash values for all the chunks from other clients and check that it has the correct hash values.
This should signal google to immediately remove all of it censorship in China
I went to a google recruitment event a couple of weeks ago. (Not that good, I have no chance of a job there and the tech talk just repeated the stuff about pagerank, GFS, spelling variations of Britney Spears and the number of querys at 2am on chrismas day a few years ago that anyone interested will already have read on the web)
Urs Hoelzle, VP Of Operations claimed that they don't censor Chineese search results at all and they are sometimes blocked in China as a result.
He also mentioned that they guess what country you are in by ip and return different result depening on which area of the work you are in you are in.
Re:This eliminates BitTorent's great advantadge
on
Decentralizing Bittorrent
·
· Score: 2, Interesting
The great thing about BitTorrent is that you are being pointed to a known file. You can judge for yourself who points you at a given file by what website is hosting the tracker.
It is possible to provide the same chain of trust in a decentralised network, just digitally sign the release notes and hash values. By checking the digital signature you can check that the file has been announced by the same group or person that announced previous files. If content announcers issue digital certificates you could pass on the digital crtificate of release groups that you trust to your firends in the same way that you could reccommend them to download via suprnova.org
The smartid detector consists of a plate antenna formed on the PCB, a couple of transistor amplifiers, two 2.4GHZ filters and a bargraph IC.
The filters are the only problem if you want to make your own. In small quantitys they are hard to source. Two filters, postage and packing will probably cost nearly as much as a wifi detector.
The article is wrong about the smartid device not detecting bluetooth. It does. It gives a signal strength idication of anything in the 2.4GHZ band. I can usually tell the difference between wifi, bluetooth, microwave ovens and wireless video camera's by the way the lights flash.
Wifi access points give a regular on-off pulsing as they send beacon frames. Bluetooth shows irregular bursts of solid-signal/no signal. Microwave ovens are generally stronger than wifi access points with a nosy flickering indication. They seems to leak more power then most wifi kit puts out. The few wireless cameras I'v found give a weak signal, close up the lower leds light solidly and the top one or two flicker.
This device is well filtered against 900MHZ and 1800MHZ cellphones. I have to hold a phone on a call close to it to get a reading despite the lack of metal shileding around the PCB. Typically the detection range is half that of a pcmcia laptop card.
Slashdot Mirror
One of the main features selling M$ Word is easy to use versioning. So, imagine people at your place of work using a Wiki instead of emailing each other 20MB binary files and overwrite each others changes all day long.
A collaborative editor might be a better replacement than a wiki. With a collaborative editor two or more people can have the same document open on different computers at the same time. When someone types words into the doucment they appear on other peoples screens in real time. With a wiki you can have the problem of two people making changes at the same time and whoever saves last overwrites other peoples changes.
Moonedit has the complete past history of the document, every keystroke.You can go back to every point in the history of the doucment and even see when someone made a type and backspaced.
That's not a problem with a collaborative editor where people are on the same LAN and are allways connected. You still have a version control problem if people work on documents offline.
I'v been using moonedit for about a year, mainly so I can have my todo list open on several computers at once. I could use a wiki but I'd have to remember to press same every time I added a two word note like "buy carrots". There are several other free collaborative editors but I havn't bothered to try them yet.
Moonedit just does text, no bold/underline/italic/fonts. I don't know off hand if gobby/ACE/subethaedit/etc have wordprocessor -like features.
http://science.howstuffworks.com/bunker-buster.htm /printable
"When the bomb hits the earth, it is like a massive nail shot from a nail gun. In tests, the GBU-28 has penetrated 100 feet (30.5 meters) of earth or 20 feet (6 meters) of concrete."
Actually I think that is evidence in favour of my point. In most places you will have hit rock 150feet down.
Here in the real world, the one in which people actually understand electromagnetic propagation through a medium, MIRACL, a megawatt-class deuterium-fluoride chemical laser, successfully disabled a satellite in orbit almost 10 years ago.
i tiative
Wrong. That test failed. It did not work.
See the wikipedia entry on SDI (assuming some stupid troll hasn't just edited it).
http://en.wikipedia.org/wiki/Strategic_Defense_In
>From what I remember of the old SDI program, a high power laser would be used to ionize air thereby creating a path for a particle beam.
I don't think that idea was ever taken seriously by anyone who knew anything about physics.
Despite wasting tens of billions of dollars on it SDI was still tens of orders of magnitude short of
the energy need to destroy missiles with space based lasers, never mind with 30Km of air in the way.
You can't ionise the air to the edge of the atmosphere, you will just pump energy into a cloud of plasma just above the laser.
>This new program [...] may not destroy the satellite but disable it, e.g. imaging sensors can only take so much photonic energy before they are burned out.
Light is scattered by the air. Even a beam of light consisting of perfectly parallel rays digerges due to equal charges repelling.
It may be possible to temporarily blind an optical sensor if it is pointed at you which a high-res spy-in-the-sky won't be but I don't believe it's possible to permanently damage a sensor from the ground. The numbers for the path loss, the amount of energy you need to damage a sensor and the beam strengh you can generate before you ionise the air add up to it not working.
This is impossible. A laser beam is a very high frequency electromagnetic wave.
It is a electric field and a magnetic field moving together.
The breakdown voltage of air is about 2000V per millimeter.
With a powerfull laser in a lab, which is about fifty orders of magnitude too weak to do anything to a satellite, you can get sparks in mid air due to the air breaking down because of the high voltage of the electric part of the electromagnetic wave.
You cannot generate a laser beam powerfull enough to destroy a satellite from the ground. IF you tried you would just make a lot of plasma in the air above your laser. Focusing lots of little lasers on a satellite would require far more lasers than could be practically built.
I suspect these storys are planted in the media to worry unfriendly countrys, just like the star wars program that never had a chance of working or the rediculous story I saw in a newspaper a couple of years ago about missiles that can burrow into the ground and destroy a shelter 150feet down.
I also think it's a sad reflection on the state of slashdot that this story is up to 150 comments and I'm the first to point this out. I'm going to go and bash my head on a wall unitl I come to my senses and stop even reading alterslash.
I happen to be working on a box thats about to get reinstalled so I broke my usually rule of allways monitoring what new software does in a virtual machine first.
./spoofer
On slackware 9.1 I get this
root@obfusticated:~#
>> Spoofing Tester v0.4
>> Rob Beverly
>> More information: http://spoofer.csail.mit.edu/
>>
>> Source 5 non-spoofed packets...
Broken pipe
tracert shows a load of packets between here and fyodor.emailtester.net (18.26.0.235)
strace shows it stopping at
write(3, "DISTANCE LINUX 4\n", 17) = -1 EPIPE (Broken pipe)
I think you'd agree that buying a treasury for 63 cents on the dollar represents a pretty good investment
Actually I believe the peak oil theory. Combined with the inevitable long term consequences of the USA's national debt passing nine trillion dollars I think that any ten year investment denominated in US dollars is horrifyingly risky.
US treasury bonds are still massively overvalued at 63cents per dollar.
Metamachine, the company that made edonkey, tried a system called transmission films. They put films on the ed2k network (edonkey, emule, shareazza) in windows media format with DRM. The idea was that people would pay to watch the films.
They had a few classic horror films and other stuff.
It appears to have been a complete failure. They took the link to transmission films off the edonkey homepage in early 2005 and the site has been down every time I'v looked since then. I tried downloading one of the films a few years ago when the site was still up to see how it worked. It took about two months because nobody was resharing the DRMed files.
It seems to me that if commercial p2p downloads don't work on the ed2k network with several million users and a link from the edonkey homepage then the idea that individuals could make any money by uploading or recommending content is laughable.
People using p2p networks simply do not want to pay.
I'm not keen on writeboard because it means leaving my information in the hands of some random website. Some documents are private and I'm not confident any dot com will be around for the long term. I'v seen a few webmail services disappear overnight along with the email I had on them.
Moonedit and gobby are worth a look. They keep the files on your machine where they can be automatically backed up and if the software falls over you have access to sort it out yourself.
Wikipedia list of collaborative editors
I work on smart cards, including biometric passports. In this field, no one in their right mind would use RFID tags for passports, or anything requiring security. Ever.
The problem here seems to be terminology (and clueless moderators).
You are incorrectly assuming that "RFID" means a simple tag with no crypto.
RFID is a generic term for any device that uses RF and identifys it's presence or absense. A resonant circuit without a chip that is used
to tag library books is an RFID. A contactless smartcard that uses cryptography to make it harder to clone is an RFID.
people then make the assumption that anything contactless is RFID
That is a correct assumption.
and thus insecure.
This is an incorrect assumption, however as Shamir has shown it is early days for RFID security.
I was similarly baffled. I work with DoD to develop and implement RFID solutions for transportation and asset accountability, and I've never heard of anyone trying to encrypt the data on an RFID tag.
Sadly I am not surprised by someone who works on a government IT project not knowing what he is talking about. The card systems currently on the market for opening doors generally use challenge-response authentication.
I'm told that the plan is for the UK RFID passports to use crypto. (and yes a contactless smartcard is an RFID.)
in the UK it is an offence to refuse to pass encryption keys to the Police if you are requested to do so.
Actually as far as I am aware a ministerial order bringing part III of the RIP act into force has not yet been issued.
That cloning device only works on cheap RFID's that don't do cryptographic authentication. This is not the first time this has been done.
http://www.cl.cam.ac.uk/~gh275/relay.pdf
The method Shamir talked about is a little more interesting because the cards are leaking information wbout what they are doing internally. It is possible that a more detailed examination of the power consumption may reveal other detail of what the card is doing as well as when it things it has receive a bad bit.
Power analysis has been a known attack on smartcards for a long time. A few cards were vulnerable to an attacker looking for increase current draw just after a PIN/password attempt when the card tried to increment a count of the number of failures, cut the power when it tries to write to the fail count and you could attempt a brute force attack. I believe the most obvious way around the problem, to decrement the counter before checking the PIN and increment it after if the check passed, is patented.
It would be interesting to see if any RFID cards have that flaw.
1: Your new service provider just puts your existing, personally owned (or given to you for free by the naming authority) IPv6 addresses into their routing tables. Everyone that had your number before still finds you at the same place.
This will not happen for cable/adsl users. There are already problems with the size of the internet routing tables, it's not practical to have a routing table entry in the big routers that connect isp's togethre for every geek at home.
The ip6 rfc actaully says that the routing is heirarchial and that ip6 addreses should not be considered to be property and can be renumbered when necessary.
"At one watt, we can cram 7.4 bits into one cycle of a sine wave.
Not quite. It suggests they can cram 7.4 bits into a 1Hz wide channel.
For example in theory you could descide to represent data using a carrier which
at any instant in time can be at one of 256 different power levels. That gives
you eight bits per symbol. To keep the frequency components of the signal within
a 1HZ channel you have to change the power level slowly which liits the symbol rate. For this to work you need the signal to noise ratio to be high enough that you can tell the difference between the different carrier levels in the time available. If you make the symbols longer you have more time to average out the noise.
Shannon's law gives the maximum amount of data that can be sent through a channel with a paticular bandwidth and s/n ratio.
No, DR DOS was originally owned by Digital Research. These were the guys that IBM originally was going to buy their dos from, but their CEO at the time blew off IBM and went sailing instead(!). He was fired soon thereafter.
That was Gary Kildall.
If you are going to repeat a computer industry myth at least get it right.
He was out flying his aeroplane not sailing and he wasn't fired, he later sold the company to Novell for 120 million.
About three years ago a usenet death penalty was issued against Telewest. Before it came into force they stopped all messages spreading out from their main newsserver and began scanning their customers for open newsservers and open proxys.
They can if you have the google toolbar installed.
A german company that I'v forgotten the name of reccently won a two year legal battle to sell box's that do advert skipping. I'd like to see it in the hands of the European masses soon as it will be hard to pass laws to ban it if lots of people start using it.
A PVR could do collabortive advert skipping. If advert skipping becomes popular then the TV companys will make it as hard as possible to automatically skip adverts. Some TV stations currently put out a fraction of a second of black at the start of an ad break or other signals that can be detected by a machine. We probably can't rely on them allways being there. The alternative is to connect PVR's to the internet. When ten people are watching a channel it would only take one to press a button at the start of and end of an ad break and everyone's PVR could skip the ads. It would require a bit of intelligence to deal with people pressing the button at the wrong moment, for example if twenty people are watching a channel you might require two people to press the skip button before it causes everyones viewing to skip
plus a rating system to detect deliberate misuse or people who just press the wrong button too often.
As I understand it, just before this latest terrorism mess started up over there, they were willing to give in to almost all of the Palistinian demands.
The fighting between zionists and arabs has been going on since before the state of Israel came into being.
The Israel's gave the Palestinian's self rule in Gaza and Jericho in 1994 after a peace agreement with the intention of a seperate state after five years. The Palestinian's continued attacking the Israel's.
Boths sides has lots of blood on their hands. The BBc has a shortish summary of the last 100 years of this conflict.
If the US didn't support Isreal there would be more chaos. The Israel's have nuclear weapons and will probably use them if it looks like Isreals will be overrun. The USA and Europe don't want millions of Jewish refugees seeking asylum.
The muslims are generally intolerant of other religions and oppress women.
a completely harmless msn plugin is set for deletetion
Actually one of my jobs this weekend is to look at a machine that is reportedly running very slowly and has a click-here-to-buy-stuff taskbar at the bottom of the screen all the time since someone clicked YES on the "messenger plus install new version" nag box.
EDonkey uses SHA1 hashes to uniquely identify files
No, it uses a custom md4 based hash. For files larger than 9.5MB the ed2k hash is a hash of the hashes of 9.5MB chunks of the file. This is so that the client can get a list of hash values for all the chunks from other clients and check that it has the correct hash values.
This should signal google to immediately remove all of it censorship in China
I went to a google recruitment event a couple of weeks ago. (Not that good, I have no chance of a job there and the tech talk just repeated the stuff about pagerank, GFS, spelling variations of Britney Spears and the number of querys at 2am on chrismas day a few years ago that anyone interested will already have read on the web)
Urs Hoelzle, VP Of Operations claimed that they don't censor Chineese search results at all and they are sometimes blocked in China as a result.
He also mentioned that they guess what country you are in by ip and return different result depening on which area of the work you are in you are in.
The great thing about BitTorrent is that you are being pointed to a known file. You can judge for yourself who points you at a given file by what website is hosting the tracker.
It is possible to provide the same chain of trust in a decentralised network, just digitally sign the release notes and hash values. By checking the digital signature you can check that the file has been announced by the same group or person that announced previous files.
If content announcers issue digital certificates you could pass on the digital crtificate of release groups that you trust to your firends in the same way that you could reccommend them to download via suprnova.org
The smartid detector consists of a plate antenna formed on the PCB, a couple of transistor amplifiers, two 2.4GHZ filters and a bargraph IC.
The filters are the only problem if you want to make your own. In small
quantitys they are hard to source. Two filters, postage and packing will probably cost nearly as much as a wifi detector.
The article is wrong about the smartid device not detecting bluetooth. It does.
It gives a signal strength idication of anything in the 2.4GHZ band.
I can usually tell the difference between wifi, bluetooth, microwave ovens and wireless video camera's by the way the lights flash.
Wifi access points give a regular on-off pulsing as they send beacon frames. Bluetooth shows irregular bursts of solid-signal/no signal.
Microwave ovens are generally stronger than wifi access points with a nosy flickering indication. They seems to leak more power then most wifi kit puts out. The few wireless cameras I'v found give a weak signal, close up the lower leds light solidly and the top one or two flicker.
This device is well filtered against 900MHZ and 1800MHZ cellphones. I have to hold a phone on a call close to it to get a reading despite the lack of metal shileding around the PCB.
Typically the detection range is half that of a pcmcia laptop card.