Computer scientists have developed a novel method for providing concrete
proof to Internet users that their information did not cross through
certain undesired geographic areas.
The new system called "Alibi
Routing" offers advantages over existing systems as it is immediately
deployable and does not require knowledge of the Internet's routing
hardware or policies.
Recent events such as censorship of Internet
traffic, suspicious "boomerang routing" where data leaves a region only
to come back again, and monitoring of users' data have alerted the
researchers.
"We became increasingly interested in this notion of
empowering users to have more control over what happens with their
data," said project lead Dave Levin, assistant research scientist at
University of Maryland in a statement.
Information transmitted
over the Internet such as website requests or email content is broken
into packets and sent through a series of routers on the way to its
destination.
However, users have very little control over what parts of the world these packets traverse.
"Alibi
Routing" works by searching a peer-to-peer network to locate "peers" -
other users running the alibi routing software - that can relay a user's
packets to its ultimate destination while avoiding specified forbidden
regions.
The peer is called an "alibi."
The alibi provides
proof that at a particular time, a packet was at a specific geographic
location sufficiently far enough away from the forbidden areas that the
data could not have entered them.
If successful, users receive
proof that their information reached its desired destination and that it
did not traverse the forbidden regions.
Alternatively, the response could indicate that the packets may have traversed forbidden areas.
"There
is also a safety parameter that we use. Basically, it is a way for
users to select a desired level of confidence that the packet absolutely
does not traverse the forbidden region," Levin explained.
The
larger the safety parameter, the harder it is to find an alibi. The
smaller the safety parameter, the easier it is to find an alibi, he
noted.
Based on simulated deployments, the system successfully found an alibi more than 85 percent of the time.
With a small safety parameter, the success rate rose to 95 percent.
"The results suggest that users can typically avoid the part of the world they wish to route around," Levin added.
The
team plans to release a version of "Alibi Routing" - likely as an Internet browser plugin - for users to test by the end of 2015.
This
new system will be presented at the Association for Computing Machinery
Special Interest Group on Data Communication (ACM SIGCOMM) conference
in London on August 20.