Security Researchers Crack APCO P25 Encryption 37
An anonymous reader writes "Two Australian security researchers, Stephen Glass and Matt Robert, have published a paper that details flaws in the encryption implementation (PDF) in the APCO Project 25 digital radio standard, used by emergency services and police departments world-wide. The paper details flaws in the DES-OFB and ADP encryption that enable the encryption key to be recovered by traditional brute force key searching. Also detailed is a DoS attack that makes use of unauthenticated radio inhibit mechanism. The research is part of the OP25 project, which uses GNUradio to implement a P25 stack using software defined radio. With this solution in place, the researchers were able to do detailed analysis of the traffic coming from various radio systems and to transmit and receive to P25 radios in their lab."
I'd buy a USRP2 receiver (Score:2)
But they cost $1700! No thank you. How many people are even using them at that price?
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Pretty reasonable really (Score:5, Informative)
Comparable equipment has traditionally cost in the 10s of thousands. Only in the last two or three years has it been in the home hobbyist range. Granted its not cheap, but its about the same as a good gaming rig. And its far less than car or shooting enthusiasts tend to spend. That said, the $1700 only includes the motherboard (fpga and ADC/DAC) and enclosure, not the receiver. The receivers range from a hundred to almost five hundred depending on what you need. Same API to control all of them though. If you want to mess with the fpga instead of doing it all on the PC you probably want the slightly cheaper motherboard so you can use the free xilinx webpack ise instead of the crazy expensive one.
Comblocks also has a nice SDR offering but getting it to the PC at a decent speed is still around $800 at least, and I don't know how clean the software interface is.
Slapping an fpga and highspeed ADC onto a custom PCB is easy enough, you can get such things from knjn prebuilt, but you really need gigabit ethernet or faster to do software processing on significant bandwidth and those sorts of interfaces tend to need five and six layer PCBs which aren't DIY and jack up the price. Perhaps the USB3 interfaces will be more hobby friendly. You still need a software controlled wideband receiver too, maybe heathkit will step up on that one.
All in all, the USRP is reasonable, though its been getting more expensive due to more features, and NI buying them might be involved too, NI doesn't tend to make cheap stuff.
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Slapping an fpga and highspeed ADC onto a custom PCB is easy enough, you can get such things from knjn prebuilt, but you really need gigabit ethernet or faster to do software processing on significant bandwidth and those sorts of interfaces tend to need five and six layer PCBs which aren't DIY and jack up the price. Perhaps the USB3 interfaces will be more hobby friendly. You still need a software controlled wideband receiver too, maybe heathkit will step up on that one.
All in all, the USRP is reasonable, though its been getting more expensive due to more features, and NI buying them might be involved too, NI doesn't tend to make cheap stuff.
Cypress already announced EZ-USB 3, if its anything like FX2LP implementing solutions will be a breeze
http://www.cypress.com/?rID=51181 [cypress.com]
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A local news service would. Typically the encrypted channels on many city police systems are the "command nets." The command nets are typically captains and above. The use of encrypted systems by "officers" generally would be limited to ERT (A.K.A. SWAT), Major Narcotics, OPR (A.K.A. internal affairs) outside of those groups most the others wouldn't care. Besides most criminals could not afford the current scanners that can grab the clear transmissions now anyway.
Funcube very much (Score:1)
FUNcube Dongle [funcubedongle.com]- A radio thats out of this world!
64MHz to 1,700MHz Software Defined Radio
funcube.org.uk [funcube.org.uk]
Quoth shoc.ch [www.shoc.ch] :
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As a ham radio operator, I know a few guys that spend 2 to 3 grand on P25 Mototola radios. I can picture a couple of them now, reading this paper over very carefully :)
Brute force? (Score:1)
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I would have thought that any wireless communication device can be easily DoSed by a normal jammer. No specific knowledge of the protocol needed.
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The others weren't australians ?
There are FOUR lights! (Score:1)
I was afraid you were going to tell me there were five researchers, but you don't even *look* Cardassian.
Catastrophic incompetence (Score:5, Insightful)
> Once a radio has been stunned by the receipt of an inhibit command the standard requires that it remains in-operational and unresponsive to the operator console or device programming interface until it receives an “uninhibit” XFC on the frequency it received the inhibit. The attack exploits the lack of any guarantee of authenticity for the frame Inhibit/Uninhibit types. [...] Note that the XFC message payload may be sent either encrypted (P=1) or un-encrypted (P=0).
Not a desirable property in a supposedly secure crypto system!
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Based on the article, it seems the system is often restricted to a small common subset of security/authentication due to needing to maintain interoperability with legacy elements (e.g. DES-OFB encryption must be available where used, but others are optional).
In other words, they (may not be able to) keep a secret because the other stuff doesn't understand HOW to.
As to how effective their security would be otherwise, I couldn't say, although apparently authentication is a major problem that would need attent
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Other parts of the article talks about security features being disabled because of interoperability. As I read the part of the article I quoted, there simply isn't any specification in the protocol to authenticate inhibit command, so this specific problem is not because of interoperability.
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The interoperability referred to is whether the inhibit request is sent encrypted or in the clear, not whether or not it had authentication. If you have the wrong crypto type, you can just fall back into clear mode for "interoperability".
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Hah yeah.
Link to previous story (Score:2)
http://it.slashdot.org/story/11/08/10/2113246/Feds-Radios-Have-Significant-Security-Flaws [slashdot.org]
APCO 25 doesn't seem to be very well thought through. Easily jammed at multiple levels and vulnerable in many ways.
--Paul
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P25 wasn't originally designed with security in mind. It was designed as a standardized digital replacement for the mess of incompatible digital and analog trunking systems that had grown up in the 80s and 90s. In its basic, as-designed, unencrypted mode, it works well. It's only when local PDs and FDs decide to try and lock out scanner users (nominally to keep criminals from listening, but more often to keep away TV news crews) by means of ill-conceived encryption addons that things fall apart.
P25 isn't "world-wide" (Score:2)
It's pretty much only used in America. Everyone else uses TETRA, or if they don't want trunking DMR or iDAS.
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Incorrect. Motorola was split into two different companies early in 2011.
Motorola Solutions -effectively the old Motorola- makes the public safety and business radio equipment and some other things. They are the ones who make the P25 and TETRA and other radio gear.
Motorola Mobility -effectively some non-core businesses which we basically spun off or shed, if you like- which makes the cellphones and cable boxes and some other things is the part Google has offered to buy. While they share the Motorola na