Slashdot Mirror
Future of Wi-Fi
An anonymous reader writes "BusinessWeek looks at the The high hurdles facing Wi-Fi. Sure it's got promise but if overcrowded spectrum isn't destined to crimp its growth, it'll need better technology and regulatory help from the FCC."
There are a couple of reasons why security at the media layer is being looked at for 802.11, specifically 802.11i (Task Group I) is specifying use of encryption such as AES at the physical layer. A main driver is that low powered devices like phones, PDAs, etc. do not have the computing power to do this in software and do robust encryption at high data rates. Adding security at the chip level will help to keep power (cpu and battery) requirements down. To respond to your point about firewalls, that is hard to do and still provide public access hotspots. You are right that protecting things at a high level is a good thing (tm) but you still need protection of the link itself.
"I say we take off, nuke the site from orbit. It's the only way to be sure."
My SMC Barricade does have a MAC filter on it to prevent that from occuring. It was in a recent firmware upgrade. It's turned off by default.
You should look up "Shannon's Law" if you really want a detailed answer to your question. In essence, the reason you can't put an unlimited number of bits into a sine wave is that the bandwidth prevents you from changing the signal too rapidly, and the noise floor prevents you from changing it by too small an amount (if you try to indicate the difference between 0 and 1 by too tiny of a change in the sine wave, the receiver will not be able to distinguish them from the natural fluctuations in the signal).
/N )
Shannon created a mathematical formula which describes precisely how much information you can transmit given a certain bandwidth and a certain amount of noise.
Precisely:
C = W log2(1 + S
C = capacity (bits/second)
W = bandwidth ( hertz )
S/N = signal to noise ratio
setting up any of that is easy, the only thing that is more secure is the login type of system.
mac filtering is easy to circumvent. I demonstrated that last month to our security chief who was bragging about our corperate deployment of WiFi gear being "un-crackable" (at least he used the right term!) I was in the network within 30 minuts. Spoofing HIS MAC address and logging in with a Manager's login that I sniffed after cracking the WEP encryption... (Why they chose to use 64bit I have no idea)
granted, I sniffed it long enough to already have the WEP key and the manager's login password 3 days before at the end of a week long sniffing session. but I wanted the impact of having the login display that I was coming from HIS laptop.
it isn't protected you MUST treat 802.11 access like dial-up or internet login. dont trust it in any way shape or form.. consider everything that is on the wireless side to be highly hostile.
We now use HTTPS for the login screen and added many more features similar to that we use for internet side logins to the network. (SSH tunneling required on all)
WiFi cannot be Consumer-secure... same as if a consumer plop'ed a server on the internet... It'll be hacked and rooted in time without difficulty. nothing will ever change that short of adding transmitter fingerprint recognition or a rolling WEP code. every packet uses a different Key from a pool of 90 bajillion keys... but what happens when the key pools get out of sync?
Do not look at laser with remaining good eye.