4 Implementation

We conduct the implementation on two TelosB Mote, one as reader and the other as user, 5, supported by UC Berkeley’s 2.x TinyOS[13] operating system6 and the NesC[14] programming language. For ECC implementation, we adapted a WM-ECC7 package for TinyOS, developed by a security team led by Dr. Qun Li at College of William and Mary. In experiments, we make appropriate modifications on their program to make them executable on TinyOS 2.x platform.

4.1 Performance Analysis

In experiments, we first measure the execution time of between the basic implementation and the scenario of adapting EC computation, which involves with several point multiplication and point addition. Here is the result:


ScenarioAuthentication Time
Basic 103 ms
EC 5000 ms

Table 1: Execution Time

The following table compares the code size of two implementation on both entry and user sides. The major difference is EC scenario occupy approximately 30kB ROM and 2.7kB RAM, whereas the basic model uses 21kB ROM and 1.0kB RAM. Both model implements Sha-1 hash function.


Scenario Entry Code Size User Code Size
Basic 21kB (ROM) + 1.0kB (RAM)21kB (ROM) + 1.3kB (RAM)
EC 31kB (ROM) + 2.7kB (RAM)21kB (ROM) + 1.3kB (RAM)

Table 2: Code Size