STARS is a statistical traffic pattern discovery system that can passively analyze encrypted traffic in mobile ad hoc networks (MANETs) to discover communication patterns without decrypting packets. It constructs point-to-point traffic matrices from captured packets and uses these to derive an end-to-end traffic matrix. STARS then applies a heuristic approach to this matrix to identify probable source and destination nodes and their relationships. Evaluation shows STARS can accurately disclose hidden traffic patterns in MANETs.