Some notes on security in the Service Location Protocol Version 2

Abstract. Service discovery protocols help users of a communication network to find services, applications, and devices that are available in the network. This feature is especially useful for mobile users in foreign networks and for groups of users that form a spontaneous (ad hoc) wireless network. As the demand for service discovery is growing, security is becoming an important concern. This paper discusses security in the IETF Service Location Protocol version 2 (SLPv2). We comment on a few security leaks in SLP and propose simple modifications in the SLP specification that make the protocol more resistant against replay attacks. Our method stores the timestamps received in service registration and deregistration messages. Furthermore, we suggest to change authentication keys after a service deregistration. Our SLPv2 implementation (TUM–SLP) demonstrates the fundamental service discovery features as well as authentication mechanisms based on DSA signature verification