TinyPEDS:

TinyPEDS is a middleware that offers a secure long-term logging of the collected environmental data over time and over some regions. It targets wireless sensor network applications where the connection to a sink device cannot be insured at all time. TinyPEDS includes the following features:

• user-friendly front end with graphical and SQL-like queries,
• mapping from meaningful semantics to WSN clusters and system epochs,
• WSN query translation, dissemination and processing,
• hierarchical and thus scalable network topology,
• continuous collection and aggregation of data, which is then encrypted and saved on the mote memory,
• backup of the encrypted aggregate to neighboring nodes for robustness purposes,
• lifetime of the WSN is enhanced by a cluster head election algorithm.