As sensor networks are deployed in adversarial environments and used for critical applications such as battlefield surveillance and medical monitoring, security weaknesses become a big concern. The severe resource constraints of WSNs give rise to the need for resource bound security solutions.In this paper we present SIGF (Secure Implicit Geographic Forwarding), a configurable secure routing protocol family for wireless sensor networks that provides "good enough" security and high performance. By avoiding or limiting shared state, the protocols prevent many common attacks against routing, and contain others to the local neighborhood.SIGF makes explicit the tradeoff between security provided and state which must be stored and maintained. It comprises three protocols, each forming a basis for the next: SIGF-0 keeps no state, but provides probabilistic defenses; SIGF-1 uses local history and reputation to protect against certain attacks; and SIGF-2 uses neighborhood-shared state to provide stronger security guarantees.Our performance evaluation shows that SIGF achieves high packet delivery ratios with low overhead and end-to-end delay. We evaluate the security of SIGF protocols under various security attacks and show that it effectively contains the damage from compromised nodes and defends against black hole, selective forwarding, Sybil, and some denial of service attacks.