Confidentiality, integrity and availability (CIA) are the three basic requirements for an encryption mechanism utilized in any security architecture. Implementation of such a comprehensive security framework for pervasive computing environment, specifically in wireless sensor networks (WSN), is not feasible in the context of scarce resource availability and its efficient utilization. Application of stream ciphers for conventional security applications has proved to be proficient in terms of efficient energy and memory consumption. This paper presents WSN-specific NesC based implementations of two stream ciphers selected from the eSTREAM project, namely HC-128 and Rabbit. HC-128 and Rabbit have both qualified for the final portfolio phase of the eSTREAM project but their suitability for WSNs needs to be justified in a totally different context. If the two stream ciphers manage to adhere to the WSN-specific requirements and perform efficiently under these requirements only then the scheme/s can be classified as suitable. This paper tends to test the suitability of HC-128 and Rabbit for WSN-specific environment and evaluates the schemes in terms of memory usage, time consumption and energy utilization. The aim of this study is to present either one of the two schemes as an efficient solution for pervasive computing.