Pwning Offender Tags (and paranoia roundup)

Man gets accused of tampering with an offender-tracking ankle bracelet. (Same as Assange wore for a while?) The ever remarkable Ross Anderson gets called by the man’s attorney as an expert witness to look into the security of the system…

Turns out offender tags aren’t quite as reliable as the company makes them out to be. He found many false alarms they’d tried to cover up, some indicating design flaws in the system, and their “forensics procedure” for detecting attempted tampering was laughable. Not to mention the issue of a private company being judge-jury-and-executioner in these kinds of matters.

After Anderson requested the judge order the tagging company open their systems to a detailed technical review, the firm hurriedly decided to drop the charges and close the case.


Paranoia roundup–

Greenwald missed something… Using open sources, someone managed to decensor some NSA slides, finding new evidence of concerted, deliberate economic espionage. That Greenwald failed to mention this in the Petrobras article (when he’d CLEARLY seen the full slide) is odd…

Schneier gets quotable:

Clapper changes his tune, what happened? My guess is they finally figured out exactly what Snowden got, and maybe even wrangled some control over what would get released in the future. Perhaps they decrypted the Wikileaks “insurance file” release, or Schneier wittingly or unwittingly compromised things (“former Chekist rule” does not specifiy wittingly so), or who knows…,0,7438979.story

Looks like Anonymous is on to something real, instead of the usual low-level crap:

For those of you in the US… imagine if John Kerry had done a photoshoot like THIS two weeks before the election. For everyone else, something entertaining from a German electoral candidate? The end of the world must be nigh.

More on Snowden’s skillset: Looks like his specialty was teaching people how to operate in high-threat *digital* environments, using untrusted hardware. Gellman thinks Snowden himself can’t get at the data anymore, though Wikileaks’ prominent “insurance” release a while ago suggests otherwise. My initial analysis (re: mental hacking) may have been wrong, or simply the kind of thing you don’t tell journalists about.

“August was a slow month, but we got a legal case where our client was accused of tampering with a curfew tag, and I was asked for an expert report on the evidence presented by Serco, the curfew tagging contractor. Many offenders in the UK are released early (or escape prison altogether) on condition that they stay at home from 8pm to 8am and wear an ankle bracelet so their compliance can be monitored. These curfew tags have been used for fourteen years now but are controversial for various reasons; but with the prisons full and 17,500 people on tag at any one time, the objective of policy is to improve the system rather than abolish it.

In this spirit I offer a redacted version of my expert report which may give some insight into the frailty of the system. The logs relating to my defendant’s case showed large numbers of false alarms; some of these had good explanations (such as power cuts) but many didn’t. The overall impression is of an unreliable technology surrounded by chaotic procedures. Of policy concern too is that the tagging contractor not only supplies the tags and the back-end systems, but the call centre and the interface to the court system. What’s more, if you break your curfew, it isn’t the Crown Prosecution Service that takes you before the magistrates, but the contractor – relying on expert evidence from one of its subcontractors. Such closed systems are notoriously vulnerable to groupthink. Anyway, we asked the court for access not just to the tag in the case, but a complete set of tagging equipment for testing, plus system specifications, false alarm statistics and audit reports. The contractor promptly replied that “although we continue to feel that the defendant is in breach of the order, our attention has been drawn to a number of factors that would allow me to properly discontinue proceedings in the public interest.” “

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