390 DEAR HACKER

390 DEAR HACKER

So you can take advantage of this system by calling any number three times. Let’s see: two house phones, work phone plus extensions, pay- phone outside of work, cell phone, friends’ phones, etc.

Of course SystemX, I believe, must make collect calls, not three free calls to any number. Depending on the cost of calls made via a pre- paid account, it may be cheaper to pay for the most basic service for

a telephone line, accept all of the collect calls you can, and repeat. This isn’t very nice or honest, but neither are the outrageous prices that inmates and their families pay to communicate by phone. Here, and in all federal prisons nationwide, inmates prepay 23 cents per minute for long distance in the U.S. The money comes right out of our accounts. If we call collect, the rate increases by four times! That’s

92 cents per minute! To SystemX and all of the rest of us who are down: I understand your

plight and hope that you can find a way to stay in contact with your family and friends. Shout out to Stormbringer!

Tony Sparx Speaking of whom....

Dear 2600: Stormbringer can open mouth and insert foot. Acidus’ article in 20:1 was

pretty close to output power on XM Satellite, which in 20:2 I said was incorrect. I read recently that XM Satellite puts out about 18kw worth of power into the antenna for an effective radiated power (ERP) of 10 megawatts or so. Sweet! I was wrong.

I have been locked up awhile so have not played with WiFi or read much about it. From previous experiences on hacking hardware, I know a lot of products can be hacked to do things the manufacturer never intended, including being on other frequencies.

As for WiFi cards, making your own channels above or below the standard ones would allow one to put up a fairly secured WLAN since script kiddies and most professional software probably won’t be looking for these channels. This could be a big problem for someone who has

BEHIND THE WALLS

I’m assuming all of the frequency channelization is done on the ROM, controlled by firmware on the WiFi card. Pretty easy to pull the ROM and blow your own and put it back in the WiFi card, the very same thing you would do with an OKI 900 cell phone or Motorola radio to make it do special things. If the card is controlled by a software driver, it would be much easier to do.

Now I have seen some block diagrams (very basic) of a WiFi card and noticed it contains everything needed to decode just about anything you could throw at it, provided you can control the frequency and deal with the bits coming out of the I/Q decoder.

The I/Q decoder is much more versatile than the 2- or 4-level decoders I’ve mentioned in the past. The I/Q decoder is limited to what you program to decode, and the sampling of the DSP chips on board. Right now I’m aware of projects, including GNU radio, that use an I/Q de- coder to do AM, FM, SSB, and some digital modulation schems such as WiFi and modes used on data over radio. Theoretically, one should

be able to decode FLEX/Golay/POCSAG pagers, digital cell phones, HDTV, satellite radio, or satellite TV via an I/Q decoder.

In the 2.4GHz frequency range, the WiFi card uses there are cord- less phones, ham radio, and other things to potentially decode. Those would be the very basic things to try out if the ROM or driver can be hacked. I do not know how far out of spec the WiFi cards can go before performance rolls off. Down at 2.3GHz we have satellite radio: XM and Sirius. A really good antenna or LNA might have a WiFi card doing satellite radio if the performance does not degrade too far drop- ping that low in frequency.

If a WiFi card can in fact be controlled to camp out on frequencies you want, and the I/Q decoders can decode what you want via roll-your- own software, there are some tricks to get other frequencies of interest converted up to 2.4GHz where we can deal with them assuming the frequencies are below 2.4GHz. For those above 2.4GHz, we would have to down convert them. That would make GSM/PCS phones, satellite TV, satellite radio, pagers, ham radio, and spread spectrum signals all potentially decodable via WiFi card.

If the WiFi card can’t be hacked, all is not lost. The I/Q decoder chips are available for pretty cheap, easily interfaceable to the computer. The