Authenticating Privately over Public Wi-Fi Hotspots

Wi-Fi connectivity using open hotspots hosted on untrusted Access Points (APs) has been a staple of mobile network deployments for many years as mobile providers seek to offload smartphone traffic to Wi-Fi. Currently, the available hotspot solutions allow for mobility patterns and client identities to be monitored by the parties hosting the APs as well as by the underlying service provider. We propose a protocol and system that allows a service provider to authenticate its clients, and hides the client identity from both AP and service provider at the time of authentication. Particularly, the client is guaranteed that either the provider cannot do better than to guess their identity randomly or they obtain proof that the provider is trying to reveal their identity by using different keys. Our protocol is based on Private Information Retrieval (PIR) with an augmented cheating detection mechanism based on our extensions to the NTRU encryption scheme. The somewhat-homomorphic encryption...

• Type: Journal
• Year: 2015
• Where: CCS
• Authors: Aldo Cassola, Erik-Oliver Blass, Guevara Noubir
• Keywords: CCS 2015, Security Privacy