This document discusses techniques for detecting node replication attacks in mobile sensor networks. It describes how node replication attacks work by allowing adversaries to create low-cost replica nodes with the same identity as legitimate nodes. Existing centralized detection methods for static networks, like using witness nodes or sending location data to a base station, do not work well for mobile networks where node locations change. The document proposes a new distributed detection method using cluster heads and encryption/decryption to detect replicated nodes based on their velocities. It argues this new method has advantages in accuracy, efficiency and reducing energy consumption compared to previous approaches.