{'fraction_non_alphanumeric': 0.011226252158894647, 'fraction_numerical': 0.0, 'mean_word_length': 5.51123595505618, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
A Dynamic Trust Establishment and Management Framework for Wireless Sensor Networks

In this paper, we present a trust establishment and management framework for hierarchical wireless sensor networks. The wireless sensor network architecture we consider consists of a collection of sensor nodes, cluster heads and a base station arranged hierarchically. The framework encompasses schemes for establishing and managing trust between these different entities. We demonstrate that the proposed framework helps to minimize the memory, computation and communication overheads involved in trust management in wireless sensor networks. Our framework takes into account direct and indirect (group) trust in trust evaluation as well as the energy associated with sensor nodes in service selection. It also considers the dynamic aspect of trust by introducing a trust varying function which could be adjusted to give greater weight to the most recently obtained trust values in the trust calculation. The architecture also has the ability to deal with the inter-cluster movement of sensor nodes using a combination of certificate based trust and behaviour based trust.