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Feds' Radios Have Significant Security Flaws
OverTheGeicoE writes "The Wall Street Journal has a story describing how the portable radios used by many federal law enforcement agents have major security flaws that allow for easy eavesdropping and jamming. Details are in a new study being released today (PDF). The authors of the study were able to intercept hundreds of hours of sensitive traffic inadvertently sent without encryption over the past two years. They also describe how a texting toy targeted at teenage girls can be modified to jam transmissions from the affected radios, either encrypted or not."
Obviously, any RF device can be jammed(if nothing else, a correctly crafted jamming signal could cause destructive interference resulting in zero signal at the receiver site; but good luck with that one...); but the difficulty of doing so can vary widely. If a spark-gap that blacks out the east coast and draws complaints from the FCC-analogs of 6 nearby countries jams something, the designer gets a pass. If some FCC approved kiddie toy can jam it, the system is likely being attacked in a manner significantly more sophisticated than brute force...
From TFA: " But, as we will see below, the situation is actually far more favorable to the jammer than analysis of its modulation scheme alone might suggest. In fact, the aggregate power level required to jam P25 trafc is actually much lower than that required to jam analog FM. This is because an adversary can disrupt P25 trafc very efciently by targeting only specific small portions of frames to jam and turning off its transmitter at other times... It is therefore unnecessary for an adversary to jam the entire transmitted data stream in order to prevent a receiver from receiving it. It is sufcient for an attacker to prevent the reception merely of those portions of a frame that are needed for the receiver to make sense of the rest of the frame. Unfortunately, the P25 frame encoding makes it particularly easy and efcient for a jammer to attack these subelds in isolation."
Oops: A sophisticated digital RF transmission mechanism substantially more vulnerable to jamming than analog narrowband...