Mobile Ad hoc Network (MANET) is a system of wireless mobile nodes that dynamically self-organize in arbitrary and temporary network topologies without communication infrastructure. This network may change rapidly and unpredictably. Application of ad hoc networks includes Academic Environment Applications, Health Care Applications, Military Applications, Bluetooth, and Personal Area Network. A service can be any tangible or intangible thing that can be useful for someone, a service can be a hardware service like a printer that can be used by a mobile device to print a file. Service discovery is defined by using one or two of Pull and Push Mechanisms. Security is a main challenge in MANETs. We propose a Secure Service Discovery Protocol for ad hoc networks (SPDPh). Simulation results of (SPDPh) and (PDP) using simulator (Ns-2) shows the extent of efficient secure service discovery protocol for ad hoc networks. Это и многое другое вы найдете в книге Secure Service Discovery Protocol for ad-hoc Networks "hash function"