Monthly Archives: September 2013

A Study of Whois Privacy and Proxy Service Abuse

Academic papers, Security economics, Web security

ICANN have now published a draft for public comment of “A Study of Whois Privacy and Proxy Service Abuse“. I am the primary author of this report — the work being done whilst I was collaborating with the National Physical Laboratory (NPL) under EPSRC Grant EP/H018298/1.

This particular study was originally proposed by ICANN in 2010, one of several that were to examine the impact of domain registrants using privacy services (where the name of a domain registrant is published, but contact details are kept private) and proxy services (where even the domain licensee’s name is not made available on the public database).

ICANN wanted to know if a significant percentage of the domain names used to conduct illegal or harmful Internet activities are registered via privacy or proxy services to obscure the perpetrator’s identity? No surprises in our results: they are!

However, it’s more interesting to ask whether this percentage is somewhat higher than the usage of privacy or proxy services for entirely lawful and harmless Internet activities? This turned out NOT to be the case — for example banks use privacy and proxy services almost as often as the registrants of domains used in the hosting of child sexual abuse images; and the registrants of domains used to host (legal) adult pornography use privacy and proxy services more often than most (but not all) of the different types of malicious activity that we studied.

It’s also relevant to consider what other methods might be chosen by those involved in criminal activity to obscure their identities, because in the event of changes to privacy and proxy services, it is likely that they will turn to these alternatives.

Accordingly, we determined experimentally whether a significant percentage of the domain names we examined have been registered with incorrect Whois contact information – and specifically whether or not we could reach the domain registrant using a phone number from the Whois information. We asked them a single question in their native language “did you register this domain”?

We got somewhat variable results from our phone survey — but the pattern becomes clear if we consider whether there is any a priori hope at all of ringing up the domain registrant?

If we sum up the likelihoods:

  • uses privacy or proxy service
  • no (apparently valid) phone number in whois
  • number is apparently valid, but fails to connect
  • number reaches someone other than the registrant

then we find that for legal and harmless activities the probability of a phone call not being possible ranges between 24% (legal pharmacies on the Legitscript list) and 62% (owners of lawful websites that someone has broken into and installed phishing pages). For malicious activities the probability of failure is 88% or more, with typosquatting (which is a civil matter, rather than a criminal one) sitting at 68% (some of the typosquatters want to hide, some do not).

There’s lots of detail and supporting statistics in the report… and an executive summary for the time-challenged. It will provide real data, rather than just speculative anecdotes, to inform the debate around reforming Whois — and the difficulties of doing so.

Google funding of open-source security projects

Open-source security, Operating systems, Security engineering

I was pleased to contribute to a recent blog article by Ben Laurie, a frequent collaborator with the Cambridge security group, on the Google Open Source Programs Office blog. We describe open-source security work OSPO has sponsored over the last couple of years, including our joint work on Capsicum, and its followup projects funded jointly by Google and the FreeBSD Foundation. He also talks about Google support for Certificate Transparency, OpenSSL, Tor, and Libpurple — projects focussed not just on communications security, but also communications privacy on the Internet.

Capsicum

Over the last decade or so, it has become increasingly (and painfully) apparent that ACLs and MAC, which were originally designed to protect expensive mainframes from their users, and the users from each other, are failing to secure modern cheap machines with single users who need protecting from the software they run.

Instead, we need fine-grained access control and strong sandboxing.
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Offender tagging

Hardware & signals, Legal issues, News coverage, Politics, Usability

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.”

The report is published with the consent of my client and her solicitor. Long-time readers of this blog may recall similarities with the case of Jane Badger. If you’re designing systems on whose output someone may have to rely in court, you’d better think hard about how they’ll stand up to hostile review.