As sensor networks edge closer towards wide-spread deployment, security issues become a central concern. Sensor networks have been identified as being useful in a variety of domains to include the battlefield and perimeter defense. So far, much research has focused on making sensor networks feasible and useful, and has not concentrated on security.We present a suite of security building blocks optimized for resource constrained environments and wireless communication. SPINS has two secure building blocks: SNEP and ήTESLA SNEP provides the following important baseline security primitives: Data confidentiality, two-party data authentication, and data freshness.A particularly hard problem is to provide efficient broadcast authentication, which is an important mechanism for sensor networks. ήTESLA is a new protocol which provides authenticated broadcast for severely resource-constrained environments. We implemented the above protocols, and show that they are practical even on minimal hardware: the performance of the protocol suite easily matches the data rate of our network.
Sensor Network Protocol Design and Implementation
Distibuted, wireless networks with limited resources
– Energy, energy, energy.
• Communication is expensive.
– Idle listening is the principal energy cost.
– Radio hardware transition times can be important.
– Low transmission rates can lower cost of idle listening.
• Nodes cannot maintain a lot of state.
– RAM is at a premium.
TAG vs. ODI
TAG: computes exact value, bound to a specific routing layer that is vulnerable to loss and requires complex synchronization– If it works right once, you get the precise answer.– Really hard to get to work right.
• ODI: computes estimate, decoupled from network layer, multipath makes it more resistant to loss, requires simple synchronization– Simple implementations can accurately compute estimate, many estimates needed for a precise answer
• TAG: implemented in TinyDB system
– Two months of work to get TinyDB to work in deployment.
– Very low data yield, no-one has been able to get it to work again (TASK project).
• ODI: a count query is 30 lines of code
– A few tricks: coarse time synchronization needed.
– Hasn’t been tested to the same degree as TAG