G
Guy Macon
- Jan 1, 1970
- 0
(Snake Oil, anyone?)
| Stealth wallpaper keeps company secrets safe
|
| August 04
| New Scientist Magazine
| http://www.newscientist.com/news/print.jsp?id=ns99996240
|
| A type of wallpaper that prevents Wi-Fi signals escaping
| from a building without blocking mobile phone signals has
| been developed by a British defence contractor. The
| technology is designed to stop outsiders gaining access to a
| secure network by using Wi-Fi networks casually set up by
| workers at the office.
|
| It is the work of moments for an employee to connect a
| paperback-sized Wi-Fi base station to a company network.
| That person can then wander around the office with their
| laptop while remaining wirelessly connected to the internet.
|
| But it is also the work of moments then for an outsider to
| breach that company's computer security using the Wi-Fi
| connection. Unless the Wi-Fi base station is protected by
| security measures that most amateur users would not bother
| to set up, it gives anyone up to 100 metres away the chance
| to bypass the corporate firewall and wirelessly hack
| straight into the network.
|
| Until now, the only way to ensure people are not illicitly
| gaining access to company secrets has been to turn offices
| into a signal-proof "Faraday cage", by lining the walls with
| aluminium foil, and using glass that absorbs radio waves in
| the windows. This ensures all electromagnetic emissions are
| absorbed, but it also means that no one can use a cellphone
| in the building.
|
| So the UK's telecoms regulator, Ofcom, has paid BAE Systems,
| formerly British Aerospace, to come up with an answer for
| firms who are becoming increasingly worried about the
| threat. BAE Systems has based its solution on the secret
| "stealth" technology that it uses to hide military radars.
| The covering, called Frequency Selective Surface (FSS)
| sheeting, is used to shroud radar antennas on warships or
| aircraft.
|
|
| Copper coated
|
|
| Solid metal antennas normally give a very strong reflection
| to enemy radar scanners. To hide them, FSS sheeting can be
| electrically set to allow through only the precise frequency
| the antenna wants to transmit and receive, while absorbing
| all other frequencies including those of the incoming radar.
|
| BAE's anti-Wi-Fi wallpaper is made from a
| 0.1-millimetre-thick sheet of kapton, the same plastic used
| to make flexible printed circuit boards in lightweight
| portable gadgets like camcorders. The kapton is coated on
| each side with a thin film of copper.
|
| On one side most of the copper is removed, leaving a grid of
| copper crosses. On the other side, matching crosses, turned
| through 45 degrees, are etched away ¬- leaving a film of
| copper with a grid of cross-shaped holes. BAE says that by
| carefully changing the size of the crosses and their
| spacing, the sheet can pass precisely defined frequencies,
| while blocking all others.
|
| But they are not revealing how the military technology works
| except to say it is a little like an optical diffraction
| grating creating interference to destroy certain light
| frequencies. "We have developed formulae for this, which we
| aren't going to give away," says project leader Kevin
| Mitchell.
|
|
| On or off
|
|
| Ofcom engineers have confirmed to New Scientist that the
| wallpaper can block Wi-Fi at 2.4, 5 and 6 gigahertz, while
| letting through GSM and 3G cellphone signals, plus emergency
| service calls.
|
| Better still, the filtering can be switched on or off if
| diodes are connected between the copper crosses. When a
| current is fed through the diodes, all frequencies are
| blocked. Switching them off "opens" the panel to let mobile
| and emergency signals through.
|
| The wall covering can be mass produced at relatively low
| cost. A square metre will cost about £500: peanuts to big
| business.
|
| BAE is now working on a transparent, ultra-thin version for
| windows. William Webb, Ofcom's R&D chief, says: "With this
| new technology, signals can be shared securely and go where
| they need to go, and no further."
|
|
| Barry Fox
| Stealth wallpaper keeps company secrets safe
|
| August 04
| New Scientist Magazine
| http://www.newscientist.com/news/print.jsp?id=ns99996240
|
| A type of wallpaper that prevents Wi-Fi signals escaping
| from a building without blocking mobile phone signals has
| been developed by a British defence contractor. The
| technology is designed to stop outsiders gaining access to a
| secure network by using Wi-Fi networks casually set up by
| workers at the office.
|
| It is the work of moments for an employee to connect a
| paperback-sized Wi-Fi base station to a company network.
| That person can then wander around the office with their
| laptop while remaining wirelessly connected to the internet.
|
| But it is also the work of moments then for an outsider to
| breach that company's computer security using the Wi-Fi
| connection. Unless the Wi-Fi base station is protected by
| security measures that most amateur users would not bother
| to set up, it gives anyone up to 100 metres away the chance
| to bypass the corporate firewall and wirelessly hack
| straight into the network.
|
| Until now, the only way to ensure people are not illicitly
| gaining access to company secrets has been to turn offices
| into a signal-proof "Faraday cage", by lining the walls with
| aluminium foil, and using glass that absorbs radio waves in
| the windows. This ensures all electromagnetic emissions are
| absorbed, but it also means that no one can use a cellphone
| in the building.
|
| So the UK's telecoms regulator, Ofcom, has paid BAE Systems,
| formerly British Aerospace, to come up with an answer for
| firms who are becoming increasingly worried about the
| threat. BAE Systems has based its solution on the secret
| "stealth" technology that it uses to hide military radars.
| The covering, called Frequency Selective Surface (FSS)
| sheeting, is used to shroud radar antennas on warships or
| aircraft.
|
|
| Copper coated
|
|
| Solid metal antennas normally give a very strong reflection
| to enemy radar scanners. To hide them, FSS sheeting can be
| electrically set to allow through only the precise frequency
| the antenna wants to transmit and receive, while absorbing
| all other frequencies including those of the incoming radar.
|
| BAE's anti-Wi-Fi wallpaper is made from a
| 0.1-millimetre-thick sheet of kapton, the same plastic used
| to make flexible printed circuit boards in lightweight
| portable gadgets like camcorders. The kapton is coated on
| each side with a thin film of copper.
|
| On one side most of the copper is removed, leaving a grid of
| copper crosses. On the other side, matching crosses, turned
| through 45 degrees, are etched away ¬- leaving a film of
| copper with a grid of cross-shaped holes. BAE says that by
| carefully changing the size of the crosses and their
| spacing, the sheet can pass precisely defined frequencies,
| while blocking all others.
|
| But they are not revealing how the military technology works
| except to say it is a little like an optical diffraction
| grating creating interference to destroy certain light
| frequencies. "We have developed formulae for this, which we
| aren't going to give away," says project leader Kevin
| Mitchell.
|
|
| On or off
|
|
| Ofcom engineers have confirmed to New Scientist that the
| wallpaper can block Wi-Fi at 2.4, 5 and 6 gigahertz, while
| letting through GSM and 3G cellphone signals, plus emergency
| service calls.
|
| Better still, the filtering can be switched on or off if
| diodes are connected between the copper crosses. When a
| current is fed through the diodes, all frequencies are
| blocked. Switching them off "opens" the panel to let mobile
| and emergency signals through.
|
| The wall covering can be mass produced at relatively low
| cost. A square metre will cost about £500: peanuts to big
| business.
|
| BAE is now working on a transparent, ultra-thin version for
| windows. William Webb, Ofcom's R&D chief, says: "With this
| new technology, signals can be shared securely and go where
| they need to go, and no further."
|
|
| Barry Fox
