: In this paper, we propose two simple and efficient schemes for establishing anonymity in Clustered Wireless Sensor Networks (CWSNs). The first scheme Simple Anonymity Scheme (SAS), uses a range of pseudonyms as identifiers for a node to ensure concealment of its true identifier (ID). After deployment, neighbouring nodes share their individual pseudonyms and use them for anonymous communication. The second scheme Cryptographic Anonymity Scheme (CAS), uses a Keyed Cryptographic one way Hash Function (KCHF) for ID concealment. In CAS, neighbouring nodes securely share the information used by the KCHF to generate pseudonyms. Even when many nodes in a neighbourhood are compromised and are colluding, our schemes guarantee complete anonymity to non-compromised nodes during their mutual communication. Our schemes have reasonably low memory and computation costs. They can be embedded into any wireless sensor setwork routing protocol to ensure anonymity and privacy during node discovery, routi...