Webpage for paranoids

Webpage for paranoids: I have been dreaming about this for a while. A global system to monitor threats world wide.

Everything is a trade-off

Security is a trade-off. Privacy as well. Are they really mutually exclusive?

Thanks Hossein!

[from: http://ocnorml.org/images/security_fence.jpg]

Securing Radio Communications in the Swiss Army

As a privileged Swiss citizen, I enjoyed a one month workshop in the Swiss army last November. During our exercises, I got in touch with digital radios tailored for military use: the SE-235. Designed by Thomson and produced by ASCOM in Switzerland, these radios protect military communications from eavesdropping. The usability of the interface is quite modest: the radios feature a set of poorly labeled buttons and a cryptic LED display showing MIX SUB.

After some web browsing, I found out that the MIX mode indicates that the radios will attempt to resist potential jamming attacks with the following strategy:

• If no jamming is detected, the radios communicate on a digital fixed frequency (DFF).
• If jamming is detected, but less than 20% of the spectrum is being jammed, the radios quickly hop over frequencies (FHOP) to evade the jamming effort.
• If more than 20% percent of the spectrum is being jammed, the radios scan the spectrum looking for available frequencies.

The SUB mode signifies that this radio operates as a slave of a single master radio. The master radio takes care of propagating which DFF or FHOP sequence to use among the nodes by sending synchronization messages. In order to use the same DFF and FHOP, all the radios are preloaded at start up with a set of DFF and FHOP sequences using a dedicated portable device: a fill gun.

To protect against eavesdropping, all the communications are encrypted. The fill gun serves to load the cryptographic material into the radios as well. I could not find details about the key distribution procedure. The simplest approach would be to distribute the same symmetric key to all the radios, and do the integrity and authentication checks using HMACs.

The fill gun is thus an extremely important piece of the military network. It contains both the frequencies and the keying material for a whole army troop. Consequently, fill guns are distributed in limited numbers and to superiors only.

As a soldier, I happened to handle fill guns more than a few times: What a privilege!

Privacy policies: What the heck happens to my personal data?

As stated by Grant Gross, online privacy policies don’t do their jobs, i.e., web sites poorly advertise the personal data they collect. Gross’s article mentions various reasons for this:

1. Not all customers are interested in looking at privacy policies. As a result, privacy policies are mostly concealed in website footers.
2. It is hard for customers to understand how their personal information is processed out of a privacy policy. Privacy policies are cryptic documents intended for lawyers.
3. Privacy policies are regularly changed by the website owner without warnings. Users have to go back to the policy to actually notice the changes.
4. Lack of standardization of privacy notices. Web users are confronted with different privacy policies at each web sites.

But, why do privacy policies matter so much after all? Well, unclear privacy policies induce information asymmetry between users and owners of a website. As studied by Akerlof, the asymmetry of information fundamentally reduces the performances of a market.

As quality becomes indistinguishable to a buyer, incentives exist for the seller to pass off a low-quality good as a higher-quality one.

In other words, as privacy-preserving products cannot be distinguished from privacy-invading products, the market of personal information may fail to exist altogether!

Hence, websites preserving privacy would actually benefit from clearer privacy policies. Lorrie Faith Cramor, an associate professor at CMU, proposes to use nutrition labels for privacy. With a comparable approach, she shows in [1] that users prefer privacy-preserving services over privacy-invading services:

[...] once privacy information is made more visible, people will tend to purchase from merchants that offer more privacy protection and even pay a premium to purchase from such merchants. This was true for both privacy-sensitive and non-privacy-sensitive items.

As a conclusion, proper privacy policies have the potential to reduce the proliferation of untrustworthy web services. While using nutrition labels tackles most of the issues, it remains unclear whether this approach will be adopted by online service providers and how it will be controlled.

[1] Janice Tsai, Serge Egelman, Lorrie Cranor, and Alessandro Acquisti. The Effect of Online Privacy Information on Purchasing Behavior: An Experimental Study. WEIS. 2007

[Via Lifehacker]

Promoting Mutual Surveillance

Spotted yesterday in Lausanne, Switzerland.

Dubious Privacy Policies

Definitely one of the most annoying issues on the Internet: long, unreadable privacy policies.

No one takes the time to read them, assuming carelessly that their privacy is protected. Still, the data is rarely safe from misuses. For example, your email address might be leaked to spammers by a misbehaving/lazy service providers. One technique to defend against such service providers consists in watermarking your emails. Assuming that you have a gmail account,

1. Use the following format when giving out your email address: username+serviceID@gmail.com where serviceID is the name of your service provider. Gmail will correctly forward the email to you.
2. Check your spam folder looking for watermarks!

Thwarting big brother

An intriguing article by the Observer suggesting 10 ways to protect privacy in our daily lives. It reminds me a typical problem of privacy: you do not know when you are being monitored, and what information is being collected. Advocating simple ways to protect your privacy is a positive step to create awareness.

[Via the New Scientist Technology Blog]

Welcome!!

Welcome to The Eavesdropper, a blog articulated around privacy questions.

This blog is after the collection and analysis of privacy threats in our increasingly ubiquitous society. The notion of privacy deserves to be enlivened to throw a light on its implications in our modern society.

Privacy has become an obscure word, crammed with various definitions and concepts. To the public eye, it has lost much of its sense. With the increasing importance of the Internet in our daily lives and the pervasiveness of mobile networks, a new class of privacy erosions is arising. Understanding privacy, knowing privacy rights, recognizing privacy infringements are of critical value to fuel a fair economy based on the Internet.