"Hi, this is a mobile device here. Here is a cryptographic
proof that I have an account on your service and I'm not a spammer. I see the
following five wireless networks." The service replies "okay, that
means you're at the corner of 5th and Main in Springfield. Here is a big list
of encrypted information about things that are nearby." If any of that
encrypted information is a note from one of Frank's friends, saying "hey,
I'm here," then his Nokia will be able to read it. If he likes, he can
also say "hey, here's an encrypted note to post for other people who are
nearby." If any of them are his friends, they'll be able to read it."
Eckersley and Blumberg also provide examples for using
cryptography in automated tolling and stoplight enforcement and transit passes
and access cards.
However, while they cautioned that the challenge of implementing
such cryptographic solutions is great, cryptographic software is already used
to protect financial services, e-commerce and telecommunications.
Moreover, they argue that while governments have a "responsibility
to their citizens to ensure that the infrastructure they deploy
protects locational privacy" companies should want to invest in such
technologies to avoid the cost of legal compliance issues.
The researchers also don't believe that
waiting for a company to offer privacy solutions as features that can
on to existing location services is an option. Instead, it is incumbent
on service providers to build these protections into their software
Unfortunately, location-based services might be one of
the last action items on the long list for federal agencies such as
the Federal Trade Commission or Department of Justice.
These regulators are
already grappling with such weighty issues as privacy in behaviorally-targeted
advertising, as well as the privacy and possible antitrust ramifications of
Microsoft's and Yahoo's search deal.
Location-based services are very much in their infancy.
Until services such as Google Latitude and Loopt see more widespread adoption,
regulators are not likely to sit up and take notice. The whitepaper from the
EFF is one seed that could be planted in the name of locational privacy.