TY - GEN
T1 - On the risks of serving whenever you surf
T2 - 8th ACM Workshop on Privacy in the Electronic Society, WPES '09, Co-located with the 16th ACM Computer and Communications Security Conference, CCS'09
AU - McLachlan, Jon
AU - Hopper, Nicholas
PY - 2009
Y1 - 2009
N2 - In Tor, a bridge is a client node that volunteers to help censored users access Tor by serving as an unlisted, first-hop relay. Since bridging is voluntary, the success of this circumvention mechanism depends critically on the willingness of clients to act as bridges. We identify three key architectural shortcomings of the bridge design: (1) bridges are easy to find; (2) a bridge always accepts connections when its operator is using Tor; and (3) traffic to and from clients connected to a bridge interferes with traffic to and from the bridge operator. These shortcomings lead to an attack that can expose the IP address of bridge operators visiting certain web sites over Tor. We also discuss mitigation mechanisms.
AB - In Tor, a bridge is a client node that volunteers to help censored users access Tor by serving as an unlisted, first-hop relay. Since bridging is voluntary, the success of this circumvention mechanism depends critically on the willingness of clients to act as bridges. We identify three key architectural shortcomings of the bridge design: (1) bridges are easy to find; (2) a bridge always accepts connections when its operator is using Tor; and (3) traffic to and from clients connected to a bridge interferes with traffic to and from the bridge operator. These shortcomings lead to an attack that can expose the IP address of bridge operators visiting certain web sites over Tor. We also discuss mitigation mechanisms.
KW - Anonymous communication
KW - Blocking resistance
UR - http://www.scopus.com/inward/record.url?scp=74049112593&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=74049112593&partnerID=8YFLogxK
U2 - 10.1145/1655188.1655193
DO - 10.1145/1655188.1655193
M3 - Conference contribution
AN - SCOPUS:74049112593
SN - 9781605587837
T3 - Proceedings of the ACM Conference on Computer and Communications Security
SP - 31
EP - 40
BT - Proceedings of the 8th ACM Workshop on Privacy in the Electronic Society, WPES '09, Co-located with the 16th ACM Computer and Communications Security Conference, CCS'09
Y2 - 9 November 2009 through 13 November 2009
ER -