We propose a secure one-time sensor scheme that is highly resistant to forged messages and replay message attacks. A sensor in a one-time sensor network transmits only a single message in its life time but retransmits messages from other sensors to provide message routing. The only security-specific computational capability required from a one-time sensor in our scheme is a hash function. The bulk of security related data in our scheme is static and therefore can be stored in non-volatile memory. This is an important design criteria as energy is the most critical resource in commonly used lowcost battery-powered wireless sensors. We further improve the storage efficiency of the proposed solution using Bloom filters. © 2005 IEEE.