Anandarup Mukherjee

Design and implementation analysis of a public key infrastructure-enabled security framework for ZigBee sensor networks

SUMMARY ZigBee is a wireless network technology suitable for applications requiring lower bandwidth, low energy consumption and small packet size. Security has been one of the challenges in ZigBee networks. Public Key Infrastructure (PKI) provides a binding of entities with public keys through a Certifying Authority (CA). Public key cryptography using public–private key pairs can be used for ensuring secure transmission in a network. But large size of public and private keys and memory limitations in ZigBee devices pose a problem for using PKI to secure communication in ZigBee networks. In this paper, we propose a PKI enabled secure communication schema for ZigBee networks. Limited memory and power constraints of end devices restrict them from storing public keys of all other devices in the network. Large keys cannot be communicated due to limited power of the nodes and small transmission packet size. The proposed schema addresses these limitations. We propose two algorithms for sending and receiving the messages. The protocols for intercommunication between the network entities are also presented. Minor changes have been introduced in the capabilities of devices used in the ZigBee networks to suit our proposed scheme. Network adaptations depending on different scenarios are discussed. The approach adopted in this paper is to alter the communication flow so as to necessitate minimum memory and computational requirements at the resource starved end points. In the proposed PKI implementation, end devices store the public keys of only the coordinator which in turn holds public keys of all devices in the network. All communication in our scheme is through the coordinator, which in the event of failure is re-elected through an election mechanism. The performance of the proposed scheme was evaluated using a protocol analyzer in home automation and messenger applications. Results indicate that depending on the type of application, only a marginal increase in latency of 2 to 5 ms is introduced for the added security. Layer wise traffic and packets captured between devices were analyzed. Channel utilization, message length distribution and message types were also evaluated. The proposed protocols performance was found to be satisfactory on the two tested applications. Copyright

A PKI Adapted Model for Secure Information Dissemination in Industrial Control and Automation 6LoWPANs

Wireless sensor nodes have a wide span of applications ranging from industrial monitoring to military operations. These nodes are highly constrained in terms of battery life, processing capabilities, and in-built memory. Industrial wireless sensor networks (IWSNs) have to meet the constraints and peculiarities of industrial environments to ensure synchronization with parallel production processes. Applications of WSNs in industrial communication vary from condition monitoring and sensing to process automation. The 6LoWPAN standard enables efficient utilization of IPv6 protocol over low-power wireless personal area networks (LoWPANs). The use of 6LoWPANs for industrial communication necessitates the fulfillment of special QoS and security. We examine the aspect of secured information dissemination for industrial control and automation processes in this paper. Researchers have proposed several schemes to secure transfer of data over the Internet. Public key infrastructure (PKI) is one of the most popular security schemes being used in the present scenario. The hostile deployment scenarios of 6LoWPANs and resource constraints of the nodes necessitate the presence of a robust security mechanism to safeguard the communication. In this paper, we propose an integration scheme for PKI and 6LoWPAN to meet the enhanced security needs of industrial communication. The approach is to delegate a major portion of key management activity to the edge routers (gateway) of the LoWPAN and limit the involvement of the end nodes to minimal communication with the edge router. We do not propose a change in the current PKI, but we put forth a scheme to facilitate the integration of PKI to 6LoWPAN in an efficient manner. The effectiveness of the proposed algorithm was evaluated using a protocol analyzer for normal 6LoWPAN traffic as well as HUI HC-01 compressed traffic. A marginal increase of 2% in channel utilization was observed, which scaled down to 1% using HUI HC-01 compression. The results indicated that the proposed algorithm can be implemented for industrial control and automation networks without any speed, security, or performance tradeoffs.

Securing intra-communication in 6LoWPAN: A PKI integrated scheme

6LoWPAN standard enables efficient integration of low power wireless networks with IPv6. However the security requirements of 6LoWPANs are high due to undefined deployment scenarios and constrained capabilities of sensor nodes. A number of schemes have been devised for secure communication over the Internet, PKI being the most widely used of them. It provides authentication, non-repudiation, confidentiality and integrity. PKI does not qualify for use in 6LoWPAN as it is not streamlined for these networks and creates a communication and processing overhead which cannot be borne by a simple wireless sensor node. We provide a scheme to integrate PKI and 6LoWPAN by essentially delegating a major portion of key management activity to the edge routers (gateway) of the LoWPAN and limiting the involvement of the end nodes to minimum communication with the edge router. The edge router maintains a Local Key Database (LKDB) by remaining in constant contact with the certification authority (CA) server and oversees all related keying functions in the LoWPAN. A request packet format and algorithm to acquire keys of the destination from edge router is proposed. Performance evaluation of the proposed scheme using a protocol analyzer indicated a time and increased packet count tradeoff for the enhanced level of security. An increase in packet payload during evaluation led to a significant increase in transmitted message count. The proposed scheme did not alter the nature of the packets transmitted and performed well at scalable loads.

Knowledge discovery for enabling smart Internet of Things: A survey

The use of knowledge discovery on the Internet of Things (IoT) and its allied domains is undeniably one of the most indispensable ones, which results in optimized placement architectures, efficient routing protocols, device energy savings, and enhanced security measures for the implementation. The absence of knowledge discovery in IoT results in just an implementation of large‐scale sensor networks, which generates a huge amount of data, and which needs, an often under‐optimized, processing for actionable outputs. In this survey, we explore various domains of IoT for which knowledge discovery is inseparable from the application, and show how it benefits the overall implementation of the IoT architecture.

Establishing the presence of Cardiac Sub-Harmonics and its Importance in detecting Cardiac Abnormalities

This paper presents a novel method for detecting cardiac abnormalities in a way which is both noninvasive and low cost. This method utilizes the presence of harmonics generated within the human heart as indicators of possible cardiac abnormalities such as cardiac blocks or cardiac valve dysfunctions. Our work is divided into two sections; firstly, the establishment of the fundamental frequency of the human heart along with its associated sub-harmonics and secondly, the presence of various harmonics in normal and abnormal cardiac signals which may serve as possible indicators to determine cardiac dysfunctions. Our method was applied on Phonocardiograph (PCG) signals of patients with various cardiac conditions.

A Fourier series based Template Matching Approach to Detect the Splitting of Second Heart Sound

In this paper, we present a method of detecting the splitting of heart sound S2 based on a template matching approach. A mathematical model of normal S2 is created and tested on other normal S2 complexes for goodness of fit. The generalized mathematical model is used as a template for detecting splitting of S2 sounds, as they will not generate a good fit with a model of a normal S2 complex. This automated detection of splitting of S2 can be used in the detection of congenital heart diseases or pulmonary hypertension. We have provided an estimate of the fit results of the mathematically synthesized S2 complex with the split S2 complexes.