Data security in telehealth and smart home environment

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I UNIVERSITY OF EASTERN FINLAND Faculty of Science and Forestry

Master’s Thesis

DATA SECURITY IN TELEHEALTH AND SMART HOME ENVIRONMENT

Author: Sujan Karanjeet Helmipöllönkatu 5 C 9

02680, Espoo Phone: +358 447388008

sujank@studen.uef.fi

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II ABSTRACT

UNIVERSITY OF EASTERN FINLAND Faculty of Science and Forestry

Sujan Karanjeet

DATA SECURITY IN TELEHEALTH AND SMART HOME ENVIRONMENT

Master’s Thesis

51 Pages, 10 Figures, 2 Tables.

Supervisors: Professor, D.Sc. (Tech.) Pekka Toivanen and Ph.D. Keijo Haataja

Keywords: Data Security, Mobile, Sensor Devices, Sensor Nodes, Telehealth, Wireless Sensor Monitoring, Wireless Sensor Networks.

This Master’s Thesis examines Telehealth care system, which is able to deliver medical services to remotely located patients using telecommunications technology like Internet and smart devices including sensors. In Telehealth care systems, security is one of the main challenges. Patients have more trust on face-to-face communications comparing to Telehealth care systems. Other challenges in Telehealth care system are the structure that needs to be built in order to monitor the patient remotely and the expenses which occur while building the network for Telehealth care system. Telehealth care systems are utilizing wireless sensor networks and devices for the communication and we need to make sure that the communication between the devices remains safe and secure. Compromise in the security of these devices could spoil the security of the whole healthcare system.

This thesis work deals with the different wireless technologies that can be involved in developing the telehealth care systems and focuses mainly on their security requirements.

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III ACKNOWLEDGEMENTS

I would like to express my gratitude to the University of Eastern Finland and the School of Computing for providing me such a great opportunity.

I would like to thank my supervisors Professor Pekka Toivanen and Ph.D. Keijo Haataja for their guidance and supervision on this thesis. I’m very grateful for their time and suggestions throughout the duration of the thesis. I would also like to thank M.Sc. Antti Väänänen for his suggestions and comments.

I’m very grateful to my wife Bandana, my family, and friends for their love and continuous support throughout the entire duration of my studies.

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IV

1. INTRODUCTION

The population of elderly has been increasing so rapidly these days. There is an expectation that the population of 60 years old and above will increase from 605 million to 2 billion by the year 2050 (Facts on ageing¹, 2014). This rapid growth of elderly results in the growth of people with chronic diseases. The cost of manual caring for elderly and the chronic disease patients are very high. It is even difficult for the family members to take care of them.

Research for improving the quality of life of elderly and the patients is becoming a very important subject (J. Edvards, 2006). People are realizing the importance of tele-health care systems and the study related to such systems are emerging as one of the most interesting fields of study.

Using the telecommunications technology such as Internet, tele-health care systems can provide the medical services to the patient located in the remote location (Qian Liu, et al., 2008). Huge number of tele-medicine devices these days use Wi-Fi (Wireless Fidelity) as a medium to send and receive medical signals that is then collected by Wi-Fi-based medical sensors. Tele-health care system provides non-invasive and inexpensive means for accurate and promptly diagnosing for many clinical conditions. It is done through continuous monitoring and medical signal analysis such as pulse, breathe rate, blood pressure, temperature, and lungs sound (Huyu Qu, et al., 2009). However, Their design and implementation have some challenges and specifically more crucial part is the security to tele-health applications. It’s very possible that the medical services are critical to the health of patients or even to their life itself (Qian Liu, et al., 2008).

These kinds of systems are precious and can be a lifesaver in many cases. However, it can also be dangerous to users when there is even a small issue or a fault in the system.

1 http://www.who.int/features/factfiles/ageing/en [Access Date: 2nd Nov 2014]

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Therefore, one of the important things to do while designing the system is to focus on the security issues and build the best possible system. This thesis is a part of the EU Artemis DEMANES (Design, Monitoring, and Operation of Adaptive Networked Embedded Systems) project² in which UEF’s CI (Computational Intelligence) research group developed the SEAL (Smart Environment for Assisted Living) system. The main idea here is to build a fully realized Telehealth and smart home systems for the elderly, the people with chronic conditions, and healthy people who want to monitor their health with unobtrusive mobile Telehealth system. The project focused on improving the independent living of the patients by monitoring and assisting them in everyday life with a secure, cheap, versatile, and adaptive Telehealth system.

The system includes a Body Area Network (BAN) with wireless sensor nodes, smart- phones, in-house automation servers, and the better means of connection between them.

The system will be responsible for analyzing and disseminating the data and will send the information to patients as well as the healthcare personnel.

This Master's Thesis focuses on the data security requirements of the project. The system will be using different protocols, standards, and different kinds of devices for sensing, tracking, transferring data, analyzing, alerting, etc. The thesis performs a study on the protocols and standards available for designing Telehealth care systems along with their evaluation. It also analyzes the data security situation planned for the SEAL system, which includes the analysis of data security in Body Area Network (BAN), Wireless Sensor Network (WSN), Client-Server communication, and User Interface Design. The analysis of security requirements is based on the efficient living of the elderly and the people with chronic diseases.

The major goal of this thesis is to find the best and the appropriate data security standard for safety, reliability, and confidentiality of the data in the SEAL system. The research methodologies used in this thesis are both Qualitative and Quantitative, which is also known as the mixed method (John W. Creswell, 2009). Quantitative method is used for

2 http://www.demanes.eu/

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comparing different standards and protocols using statistical data, while Qualitative method is used to find out the importance of standards and protocols. Additionally, review of literature is done as a method of research. In a literature survey, topic is selected and writing part is done reflecting the topic, which is followed by studying the existing literature in relation to the topic. The literature review provides the result of other studies and findings that are closely related to the specific topic and it can further be helpful in filling research gap. For example, topic can be WSN, sensor devices, wireless technologies, standards, protocols, data security, network security, technology, and other topics as well.

The primary information gathered is mostly from conference articles, journals, books, and Internet sources.

The study work has been developed with the help of required academic materials from databases such as IEEE. Focusing on journals and articles as well as relating them to the framework of this thesis helped in developing of the Research Questions. Framework developed as shown in Figure 1 supported a lot in generating research questions.

Although there were lots of literature reviews for this study, the priority was given mainly to the literature information that was relevant to the research questions.

The research questions are as follows:

1. What are the standards for data security in Tele-health?

2. What kinds of protocols are used in Tele-health?

3. How can SEAL be made safe, reliable, and confidential?

4. What is the most appropriate data security standard for safety, reliability, and confidentiality of the data in SEAL?

5. What are the limitations of the system?

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4

Figure 1. Thesis Framework.

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Chapter 2 defines Telehealth care system as a medical device. It will focus on using IT (Information Technology) and Tele-communication to provide assistance on the health care system. It helps the reader to understand the basic workflow of the Telehealth care systems and the necessary components required to build up the system and the importance and type of communication channels being used in today’s health care system.

Chapter 3 consists of the definitions of wireless sensor network, its structure, wireless network topologies, communication link, and wireless standards. It also briefly defines the sensor node, base station, and communication link. This chapter shows how the signal is generated by target node, how data is transmitted from a target node to the sensor node or a base station from sensor node and sent to mobile devices, personal computers, and other display devices. It also defines the sensor node architecture, which enables the reader to understand how the sensor node operates in real world environment. As the overview, Chapter 3 provides the detailed information on different wireless network topologies and different characteristics between star and mesh wireless network topologies.

Chapter 4 deals with data security. This chapter defines the security requirements, which allow the reader to understand the basic requirements for data integrity, data authentication, and data confidentiality. This chapter includes the detailed description about the wireless standards like Bluetooth, ZigBee, Ultra-wideband, and Wi-Fi. The importance of this chapter is that it allows the reader to clearly understand what type of security one can achieve with the use of those wireless standards. It defines in details the strengths and weakness of using each of those wireless standards in Telehealth care system. This chapter also defines several types of attacks and threats that could be encountered with the use of the wireless standards.

Chapter 5 consist the core part of this thesis. This section covers an analysis and a comparison of different types of wireless standards are made on the basis of the basic attributes like range, signal rate, type of cell used, encryption, authentication, and the data

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protection. The main importance of this chapter is that it allows the reader to select the correct wireless standard in Telehealth care system in order to get the data secured.

Finally, Chapter 6 will conclude the thesis with some future research work ideas.

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2. TELE-HEALTH CARE SYSTEM AS MEDICAL DEVICE

Tele-health is defined as a support system that uses telecommunication technology for facilitating the health care and services to the remotely located, physically confined person and geo-graphically dispersed people by exchanging information between the providers and the patient (Tele health Handbook³, 2013). Telehealth is also defined as the use of telecommunications and IT for providing access to health assessment, intervention, education, diagnosis, supervision, consultation, and information across distance” (Morreale, P.A., 2007).

Tele-health systems are simple as well as complex. Simple Tele-health system uses a computer and a telephone for providing health care, whereas complex Tele-health system uses latest mobile devices and latest technology. Simple Tele-health system is also called as informal Tele-health system (Garripoli, C, Mercuri, M. et al., 2015). Tele-health care systems today use wireless sensor nodes connected to the mobile devices and servers.

Tele-health system is therefore used as a tool for managing long-term conditions for proactively monitoring patient’s health. The approach of patient management would allow data transfer in timely manner and an immediate feedback. In Tele-health, system should promptly send a response to indicators of acute signals. By monitoring vital signs, Tele- health care system reduces unnecessary hospital admissions (Mei-Ju Chen, et al., 2012).

The very basic Tele-health system consists of end instruments like sensor devices, which take physical signals as input from patient and convert them to the electrical signals.

Then, those electrical signals are communicated to other end instruments or directly to clinical persons or doctors through communication channel like wireless communications (Garripoli, C, Mercuri, M. et al., 2015). Other end instruments here mean databases. In the database, all the health records are stored and this information is communicated as output to doctors. In response to the information received remotely from patients, doctors

3 http://www.eric.ed.gov/PDFS/ED165952.pdf

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make the analysis and send them feedback accordingly. In this way, the basic Tele-health care system works. Figure 2 shows basic Tele-health system elements.

Figure 2. Elements of a Basic Telehealth system (W. Leister et al., 2008).

End user Instruments

End user instruments are the transducers, which act as interface between the patient and the communication channel. Input transducers and sensors receive signals from patient and convert those signals into electrical form. The electrical form of signal is then transmitted to other end through a communication channel. Then the output transducer will convert the received signal into representable form in the other end and the data is saved in a database (W. Leister et al., 2008).

Communication Channel

Communication channel acts as an intermediate link between sensor nodes and the network. In Wireless Sensor Network, communication channel can be either short range communication link or long range communication link. Nowadays, Bluetooth is the most commonly used in short-range communication. The public networks, which are based on various technologies like GPRS (General Packet Radio Service), GSM (Global System for Mobile communication), WiMAX (Worldwide Interoperability for Microwave Access),

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UMTS (Universal Mobile Telecommunications System) and others, are used for long range communication (W. Leister et al., 2008).

System Design / Devices

A typical Tele-health care system consists of a Wireless Body Area Network, Wireless Sensor Network, Mobile devices, and Application Server as shown in Figure 3.

Wireless Body Area Network (WBAN) is emerging as one of the most suitable technologies in the field of healthcare technology supporting a wide range of medical and non-medical applications (Ramli, S.N, et al., 2013). It consists of sensor nodes capable of sensing and processing more physiological signals, storing and transmitting the data to other nodes, and the whole network.

Wireless Sensor Network (WSN) is a technology similar to WBAN but the sensors are not in the patient’s body. Sensor nodes cost less, need less power, and other multifunctional aspects allow them to be deployed in a wide range of areas (Morreale, P.A et al., 2007).

Central Nodes are the mobile devices, which are connected to the sensor node devices with short-range communication technologies, which would be Bluetooth or ZigBee. It gathers all the information from sensors and transmits them to the application server using long-range communication like Wi-Fi.

Application Server analyzes all the information gathered from the central nodes. It presents the information to the health personnel located at a different place in a User Interface.

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Figure 3. Tele-health care system (C. Zhou et al. 2013, R. Woo et al. 2015).

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3. WIRELESS SENSOR NETWORK

Nowadays, WSN is applicable to military applications, home applications, medical applications, building monitoring, machine conditions monitoring, distributed temperature monitoring, transportation, industrial monitoring, environmental monitoring, energy monitoring, and many other use cases as well (M.Sharifi et al., 2009; Chee-Yee Chong &

Srikanta P.Kumar, 2003). Wireless Sensor Network is made up of a number of sensors or motes, small in size, have limited memory size with sensing capabilities, and are cost effective (P.Radivojac et al., 2003, S.Krco et al., 2005 A.Ali et al., 2006; W.Leister et al., 2008, Rehena, Zeenat et al., 2011). Wireless Sensor Network also performs data processing tasks and can communicate wirelessly to other similar devices by single-hop communication or multi-hop communication.

Wireless Sensor Networks are deployed as ad-hoc network whereas sensor nodes are placed in geographically suitable area and they do not require any human supervision.

Spatially distributed sensor nodes receive signals from environment and respond to signals either periodically or continuously based on the requirements. Sensor devices measure the physical quantity like heat, temperature, light, radiation, pressure, etc. After receiving the signal, sensor devices then convert them into signal, which is understandable to readers and by instruments. (A. Ali et al., 2006)

Basically, a Wireless Sensor Network has a sensor node, target node, and BS (Base Station) or sink node. Target node generates signals called as stimuli. Sensor node detects signals that are generated by target node and forward the data to BS or sink node.

Then BS performs appropriate action. Finally, it allows user to sense and monitor data from distance using desktop computer, mobile devices, and others and does it very effectively. Many researchers have suggested that it is very important to know about the sensing task at the time of WSN deployment devices (Rehena, Zeenat et al., 2011; S.Krco et al., 2005; A.Ali et al., 2006; P.Radivojac et al., 2003; W.Leister et al., 2008).

Figure 4 shows an overview of a typical Wireless Sensor Network environment.

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Figure 4. An overview of a typical Wireless Sensor Network Environment (A. Abahsain et al. 2013).

The wireless sensor network is composed of sensors, base stations and communication links, which are defined in detail in section 3.1. It is followed with the different types of network topologies in section 3.2.

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3.1. STRUCTURE OF WIRELESS SENSOR NETWORK

The structure of WSN is shown in Figure 5. According to Liu in (WenjinXu&Jianfeng Liu, 2008) every task performed by WSN included retrieval of information from the environment. When there are many sensor nodes used in WSN, it increases the extended range of sensing, robustness, and fault tolerance as well as improves the accuracy and lowers the cost for data availability.

Figure 5. Wireless Sensor Network Architecture (Z. Dai et al. 2012).

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14 Sensor Node

As Figure 5 illustrates, the collection of sensor nodes makes each sensor network.

Sensors in sensor network collects or sense the information from certain area or from certain object of interest as the sensors are interconnected with each other and distributed in an appropriate environment (I.F. Akyildiz et al., 2002). Sensor network consists of many attributes such as sensor size, sensor type, number of sensors, composition, coverage area, deployment, sensing entities of interest like mobility and nature, operating environment, communication behavior, architecture and energy availability.

There are three types of sensor networks: Centralised, distributed, and hybrid. When all data is sent to central site, it is called as centralised sensor network and when data can be located at sensor itself or in other sites, it is called as distributed sensor network. Some examples of sensor nodes are Tactical Remote Sensor System (TRSS) Node (Sang Hyuk Lee, et al., 2009), ember (Chih-Chun Chang et al., 2008), and others. There are four primary components in sensor nodes, which are processing unit, sensing unit, transceiver unit, followed by a power unit (see Figure 6). Sensor nodes also consist of application dependent component like mobilizing system or localization system. Power unit is supported by batteries, such as AA batteries or solar power depending on the generations of sensor nodes used. (Chih-Chun Chang et al., 2008)

Sensing Unit consists of ADC (Analog to Digital Converter) and sensor. Sensor is a device that measures physical parameters. Properties of sensors define the characteristics of the sensors. Properties of sensors may include manufacturer size, weight, sensory type, calibration date, and others (S.Krco et al., 2005). In today’s market, there is a wide variety of sensor types such as seismic, thermal, visual, acoustic, infrared, and magnetic. A sensor can be an active sensor if it uses active manipulation of environment to sense data, for example, radar. Similarly, if sensing is carried out without active manipulation of environment, then it is regarded as passive sensor. Initially, the sensed information is in analog form, thus to make it digitised, ADC (Analog to Digital Converter) is used. An output from ADC is provided as an input to the processing unit (I.F. Akyildiz et al., 2002).

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Figure 6. Sensor Node Architecture (Liu W. et al. 2012).

Processing unit consist of storage unit and processor. Activities like data processing and classification occur within the processing unit. By collaborating one sensor node to other sensor node, processing unit manages the procedures in order to finish the assigned sensing task.

Finally, the transceiver is capable of transmitting and receiving the data to other devices by connecting a wireless sensor node into a network. Communication between the devices in wireless sensor network occur using RF transceivers and other wireless technologies such as Bluetooth and ZigBee.

Sensing of information and routing of data depends on exact location of sensor nodes.

Localisation unit manages the routing table while transmitting the information from one node to the other. Information related to location with high accuracy is very important in

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wireless sensor network during sensing of information form environment or from user movement. Localisation system is needed based on the application and end user monitoring requirement. But mobilisation unit is required only when there is requirement for sensor nodes to move from one place to another unit (I.F. Akyildiz et al., 2002).

Base Station

Base station (BS) is regarded as a central node in wireless sensor network. Information received by the sensor node is sent to the BS. Properties of the BS are similar to personal computers (PCs), thus it is regarded as a powerful device. BS can collect, store, and control the information received from the sensor nodes and route it back to required destination. In comparison to sensor nodes, BS has unlimited power supply. Nowadays we also have mobile base stations with more advanced computational capabilities. End user using mobile or computer system can be easily connected to BS, from BS end user can retrieve the data provided by sensor nodes to BS. BS also acts as interface between sensor network and Internet in case of front-end proxy solution where sensor node cannot be directly connected to Internet as every information need to be parsed through BS.

Depending on the scenarios, sensor nodes are independent of Internet and it facilitates sensor node from implementing own protocols and algorithms as well. In gateway application, BS sometimes acts as application layer. It is important to maintain the independence from sensor network point of view as the exchange of information between sensor node and Internet occurs directly. In order to maintain the independence of sensor network, it requires translation table. These are mapped to the sensor node address to Internet Protocol (IP) address. BS can also act as a router in the sense that it forwards packets to and from the sensor node in TCP/IP (Transmission Control Protocol / Internet Protocol). Sensor node itself is able to behave as a web servicer as it can reports its interface with the help of WSDL (Web Service Description Language) and connecting to other host using HyperText Transfer Protocol (HTTP) (Sang Hyuk Lee, et al., 2009).

BS needs to be placed in correct location. The positioning of BS influences various important factors like improvement in network performance, throughput, and increase the

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lifetime of network, balance energy expenditure, flow of data in WSN, and data rate (Sang Hyuk Lee, et al., 2009). Base station behaves like a sink node for the data that gets collected. According to most of the research performed, careful positioning of BS is important, because routing of data from source sensor to BS leads to numerous relay nodes, which further increase aggregate delay, more power consumption, and also risk chances of packet loss due to error in the links (I.F. Akyildiz et al., 2002, K. Akkaya et al., 2007). BS are positioned either statically or dynamically. In static positioning, each sensor node is transmitting some data at a fixed rate without any compression or suppression.

Based on exact node location, static BS positioning is defined. Sensor node locations are structured through Global Positioning System (GPS). Power saving can be achieved if the distances between the nodes are minimised. Compared to single static BS positioning, multiple static BS positioning is more challenging, as sensor node has to select among multiple destination to send data. Challenges occur in multiple static BS positioning due to type of network architecture. There are different approaches defined for multiple static BS positioning. Dynamic positioning of BS improves the network performance when network is operational by reducing effect of packet drop caused by links and node failure. Moving the BS toward highly loaded BS improves network performance by maintaining energy consumption, throughput, and delay (Sang Hyuk Lee, et al., 2009).

Communication Link

Wireless Sensor Network uses of two types of communication links: One is short-range communication link and the other is long range communication link. Most commonly, public networks that are based on various technologies like GSM, UMTS, GPRS, WiMAX are used for long-range communications. Nowadays, Bluetooth is mostly used in case of short-range communication (W. Leister et al., 2008).

The main function of a communication link is to act as a link between sensor nodes and a network. Short-range communication links in the Tele-health care systems are basically

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used to transmit the data among the end user devices to the sensor nodes and the long range communication links are used to send or receive the data from the nodes to the file or database server where the user’s data will be saved. The saved data should be sent to the health care personnel for the analysis and this can be achieved via the long-range communication links as well.

3.2. NETWORK TOPOLOGIES

Network topology is very important to be considered while deploying WSN. Network topology helps in determining the connectivity between nodes, which is necessary while routing data from one node to other nodes and BS during deployment phase (I.F. Akyildiz et al., 2002). There are different types of network topologies in WSNs. They are Star Topology, Mesh Topology, and Star-Mesh Hybrid Topology. Based on the transmission data frequency, distance of transmission, battery life, requirements for mobility, and level of changes in sensor nodes are all needed when choosing the appropriate WSN topology.

Star Topology

A star network topology is made up in such a way that a single BS is able to transmit or retrieve messages from or to a number of remote nodes is characteristics of a star network topology. In star topology there are many remote nodes, which are identical to each other and are connected to single BS for sending and receiving the data (Xiaodong Wang et al., 2007). It’s a single-hop topology where the available wireless sensor nodes can connect directly and are in between thirty to hundred meters to a BS. BS in star topology can be PC, PDA (Personal Device Assistant), dedicated devices for monitoring, or it can be other gateways to higher data rate device. Gateway communicates between the nodes, as nodes in star topology cannot send data to each other directly. BS also

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transfers data to higher level such as Internet. As there is a single BS, there is always a requirement for better routing, message handling and proper decision-making capabilities than other nodes. Star topology helps to reduce power consumption of the remote nodes.

However, it is limited to transmission distance of a radio, which is typically 30-100 meters in each node. Whenever the communication link is lost then it affects on a single node.

However, BS should also be in the communication range or otherwise the links in the network will be lost.

Some of the disadvantages of star topology are that it lacks robustness and scalability due to single hop and routing techniques. If there occurs any failure, then there is no alternative communication path in star topology as shown in Figure 7.

Figure 7. Star Topology (Xiaodong Wang et al., 2007).

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20 Mesh Topology

Mesh topology is available in Figure 8. Its a multi-hop system and decentralised in nature where all wireless sensor nodes are alik’e to each other. Nodes in mesh topology can directly communicate to each other, skipping a communication to the BS. It has distributed network where it allows transmission to nodes that are nearest neighbours (Xiaodong Wang et al., 2007).

It is very helpful for large-scale network of WSNs that can stay distributed over a large geographic region due to its multi-hop nature. Mesh topology is scalable and reliable because there is no single point of failure. It also provides many alternative communication paths. Additionally, it reconfigures new connections automatically around the failed sensor node.

Some disadvantages of mesh topology are as follows. With mesh topology, latency might be increased as the number of nodes increase. Also, the distances between them might increase the latency as sensor data from node to node is hopped when sending data to BS. In mesh topology there is a significant high power consumption, which is caused due to higher duty ratio of mesh network, as it has to always remain in the listening state for message or for change in prescribes route through mesh.

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Figure 8. Mesh Topology (Xiaodong Wang et al., 2007).

Star-Mesh Hybrid Topology

In hybrid topology (see Figure 9), wireless sensor nodes will be arranged as in star topology around routers where routers put themselves in mesh network and serves to increase the network range and to provide better fault tolerance (Xiaodong Wang et al., 2007).

Some of the advantages of using hybrid topology are that it is reliable as there isn’t a single point of failure, it also provides alternative communication paths and has lower power consumption compared to mesh topology. Additionally, it provides robust and versatile communication network due to which it offers very good mobility and flexibility of sensor nodes. For example, ZigBee uses mesh topology.

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Figure 9. Star-Mesh Hybrid Topology (Xiaodong Wang et al., 2007).

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4. DATA SECURITY

The amount of data has been increasing every day in this technology-oriented world.

There is networking and technology everywhere in the world today and with our important data all around, the concept of data security has a very significant meaning in today’s world. Data security not only deals with the data stored in a device but it also includes the securing of information during data communication.

Data in today’s world could include all the personal information, which people do not want to share with anyone else but they exist in the system isolated from others. If the system is not secure enough and those important personal information is exposed, it could be a very big problem to the people as well as the designer of the system. Thus we have to agree that the security of the data is very important when designing any systems, which contain the information or from which the information is transmitted.

Malicious attacks might take place on the wireless networks and some threats are very difficult to be avoided as well (Wen-Bin Hsieh, et al., 2013). The attacker might obtain the important information very easily if the system is not properly secured.

Wireless networks in the industry are especially very vulnerable to the threats and attacks these days. Some potential security threats are even difficult to be avoided. Tele-health care systems will have a lot of information on the patient’s health. Losing this information to someone might turn out to be very dangerous.

The requirements of the security are elaborated in the first section below Standards and protocols like Bluetooth, ZigBee, Ultraband and WiFi are defined in the later section.

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24 4.1. SECURITY REQUIREMENTS

People are very much concerned about the privacy of their data. Possible weakness in security of a wireless system should be recognized so that the right measures can be taken to improve the user level confidence.

Tele-health systems require data privacy, security, and physical security. A very small carelessness in the Tele-health security could really have a big impact to everyone involved (Huyu Qu, et al., 2009). These systems can have personal data of huge number of patients, which could be quite critical to loose (Alfaiate,J , et al., 2012). It will be a big loss to the health service providers and the patients themselves if their critical data is compromised in any possible way. Thus it is very important to have an analysis on the security risks before developing the system (Adekunle, A.A, et al., 2009). There should be a very good trust relationship between the patients and the health care professionals.

Otherwise, the patients might not provide the accurate or crucial information, which could directly affect the quality of service of the health service itself.

Problems like authorization, authentication, and accounting are important while considering the data security. Different devices and standards for communications should be studied properly. Any health care systems should have the security requirements for the following: Data Integrity, Data Authentication, and Data Confidentiality.

Data Integrity

Data integrity requirement should ensure that the transmitted data from source to destination is unaltered by any means. The data could be intercepted in transit and can be modified (Adekunle, A.A, et al., 2009). Therefore, the data checks should be performed so that the receiver could confirm that the data is not altered. Data integrity can be achieved by checking the fingerprint of the data.

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25 Data Authentication

Data authentication is the process that lets us know that the sender is truly the sender of the data (Huyu Qu, et al., 2009; Alfaiate,J , et al., 2012). The sender should be authenticated so that the attacker pretending to be the sender would not be able to fake the communication. Data authentication is performed with Message Authentication Code (MAC), a hash value that with its secret key being encrypted. Moreover, it used one-way hash function and only the sender and receiver know the encrypted secret key.

MAC can take care of the integrity and authentications, but the data that’s protected is in a clear text, which brings the new requirement of the data encryption (Adekunle, A.A, et al., 2009).

Data Confidentiality

Data confidentiality is the process of hiding the information so that only the recipients could know of what’s being transmitted by the sender. It can be achieved by using the data encryption algorithms, which are defined below.

Symmetric key encryption is the encryption where the receiver share the common key used for both encrypting and decrypting of data (Huyu Qu, et al., 2009; Alfaiate,J , et al., 2012). Advanced Encryption Standard (AES) is the mostly used symmetric algorithm.

Public key encryption is the encryption that has the public key as well as the private keys.

The main idea is that the only holder of the correct public-private key pair can decrypt the encrypted message.

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26 4.2. STANDARDIZATION AND PROTOCOLS

Following are the mostly used Wireless Sensor Network standards and the ones that will be studied in more details: Bluetooth, ZigBee, Ultra-Wideband (UWB), and Wi-Fi.

Bluetooth

Bluetooth is one of the most emerging technologies for connecting different fixed and portable devices over short distances. The growing world of mobile phones is increasing the importance of the Bluetooth technology. It is small in size, lightweight, and it provides are very good performance.

Bluetooth includes software and hardware definition for short range, low power, and low cost radio link (Hongyu Chu et al., 2010). It has both link layer and application layer definition for the product developers, making it different from other wireless standards (Alfaiate,J , et al., 2012; Bandyopadhyay, S, et al., 2003). IEEE 802.15.1 standard defines wide range of electronic devices to have a uniform structure so that communicating between the devices would be possible. It uses star network topology and follows master slave concept where master device acts as single base station and communication medium for other seven remote nodes. Frequency band, channel arrangements, and transmission characteristics for a Bluetooth device are defined in the radio layer.

(Alfaiate,J , et al., 2012; Bandyopadhyay, S, et al., 2003).

Bluetooth operates at 2.4 GHz frequencies in the free ISM (Industrial, Scientific, and Medical) (Hager, C.T, et al., 2003). It consists of total bandwidth of 83.5 MHz. The bandwidth is divided to 79 channels where every channel has a bandwidth of 1 MHz.

Radio frequency (RF) connections with other Bluetooth devices are handled by the Baseband layer. The layer is also able to distinguish between Synchronous Connection- Oriented (SCO) and Asynchronous Connection-Less (ACL) packets. The Link Manager (LM) layer of Bluetooth protocol stack handles link security, link setup, and configurations (Hager, C.T, et al., 2003).

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Common interface between host stack, lower level, and hardware-oriented layers are provided by HCI (Host Command Interface). L2CAP (Logical Link Control and Adaption Protocol) is considered as data link layer of the stack and it allows transportation of data packets. Today, some of the health equipment uses Bluetooth and its output power is 100 mW, which is sufficient for indoor environments (N.Nakajima, 2009).

Transmission rate of basic Bluetooth (without any speed enhancements) is 1 Mbps, which is greater than that of IEEE 802.15.4 whose transmission rate is 250 kbps (Alfaiate,J , et al., 2012). There are some limitations of Bluetooth device as well. Blutooth devices relatively use high power for short transmission range. Node synchronization to the network takes longer when returning from sleep mode which inturn increases the average power of the system. It also has less number of nodes per network that is, it allows only seven nodes in a network.

Ten different versions of Bluetooth have been released so far: 1.0A, 1.0B, 1.1, 1.2, 2.0, 2.1+EDR (Enhanced Data Rate), 3.0+HS (High Speed), 4.0, 4.1, and 4.2. The main security enhancement was released with version 2.1+EDR when SSP (Secure Simple Pairing) was introduced. Version 3.0+HS provided support for the use of WLAN when there is a need to transferring a large amount of data, thus giving transmission rates up to 24 Mbps. When there is no need to use higher speeds and thus device can save energy, transmission rate of 3 Mbps provided by the EDR will be used. Bluetooth versions 4.0-4.2 support LE (Low Energy) that further reduces the energy consumption and allows batteries to last for several months. Bluetooth LE devices also support LE Privacy mode that can be used to protect the identity of the device by using a pseudorandomly generated Bluetooth device address value. The old SAFER+ (Secure And Fast Encryption Routine +) algorithm was also updated to much safer AES (Advanced Encryption Standard) for Bluetooth versions 4.0-4.2.

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28 Bluetooth Security

When Bluetooth was introduced for the first time, it had a lot of security issues. Version 2.1+EDR, which was the sixth release, introduced more security features than other versions (Alfaiate J., et al., 2012). Bluetooth security is totally based on the authentication and encryption.

Four modes of security modes are available in Bluetooth. Security Mode 1 uses the unsecure links and does not need any authentication or any encryption. Security mode 2 has a security manager, which is able to control the access to different devices and services. It is only initiated after the link has been established (Hager, C.T, et al., 2003).

This level of security uses authentication and encryption for communication of individual services only. Security mode 3 fully supports authentication as well as encryption and is enforced to authenticate and encrypt before the link establishment. The device is initiated with the security process before the establishment of the physical link so all the traffic is encrypted. It is considered to be the strongest mode from NIST (The National Institute of Standards and Technology) because of the execution of authentication and encryption feature before the link establishment.

Security Mode 4 is a service level mode introduced in version 2.1+EDR. It is initiated after the link establishment. This mode has the SSP method for creating service level security.

Bluetooth also has some confidentiality service for tackling eavesdropping attempts on the payloads of exchanged packets. It has 3 encryption modes. Encryption Mode 1 does not have any encryption on the traffic. Encryption Mode 2 has encryption on the basis of individual link keys (Bouhenguel, R, et al., 2008; Karen Scarfone, et al., 2008). It actually broadcasts the traffic. In Encryption Mode 3, all the traffic is encrypted based on the master key. Common encryption mechanism is deployed in both Encryption Modes 2 and 3.

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Bluetooth provides four different options for its discoverability and connectability. The four options are Silent, Private, Public and LE (Low Energy) Privacy (Haataja K. et. al, 2013):

 Silent: This option makes the Bluetooth device not to accept any Bluetooth connections ever. It will only monitor the Bluetooth traffic.

 Private: The Bluetooth devices with private mode accepts connection only when the prospective master knows BD_ADDR (Bluetooth Device Address). The device cant be discovered at all with this option and it is also called non-discoverable device. Normally, a 48-bit BD_ADDR are unique which refers globally to only one indivitual Bluetooth device.

 Public: Bluetooth device with public mode option are called discoverable devices as it is both discoverable and is able to be connected.

 LE Privacy: These devices with LE Privacy mode is able to protect the ID (identity) of the device with the use of a pseudo-randomly generated BR_ADDR value. The BD_ADDR will be changed to a new pseudoramdom value after some predetermined time. The communication of such devices therefore looks like there are several different devices communicating which provides better protection agains device survelliance / tracking based attacks.

It would also be good to define the two levels of service security. Service security could be trusted or untrusted depending on its relationship with another and the level of access.

A fixed relationship is maintained between a trusted device and the other device and has full access to the services (Suri, P.R, et al., 2008; Tan, M, et al., 2011; Sandhya, S, et al., 2012). No relationships are established with another device in an untrusted service and there is no restricted access to the services.

John Paul Dunning has made a very interesting classification of the Bluetooth attacks and prioritized them according to the threat of the attack (see Table 1). He classifies the attacks to be Man-in-the-Middle attack, unauthorized direct data access (UDDA),

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malware, denial-of-service, Sniffing, Fuzzer, Obfuscation, Range Extension, and Surveillance (Suri, P.R, et al., 2008; Tan , M, et al., 2011; Sandhya, S, et al., 2012).

Table 1. Bluetooth Attacks (Suri, P.R, et al., 2008;

Tan , M, et al., 2011; Sandhya, S, et al., 2012).

Classification: Attacks: Purpose:

Man-in-the Middle

BlueSpoof, bthidproxy, BT-SSP-Printer-MITM

Placing a device in between two connected devices.

UDDA

Blueover, BlueSnarf, Bluesnarf++, Bluebug, BTCrack, HeloMoto, btpincrack, Car Whisperer.

Gather the unauthorized information.

Malware Caribe, CommWarrior,

Bluebag

To attack using self- replicating software form.

DOS

Battery Exhaustion, BlueSYN, signal jamming, Blueper, vCardBlaster, Bluejacking,

To deny resources by saturating communication channel.

Sniffing Merlin, BlueSniff,

Wireshark

To Capture traffic transferred.

Fuzzer

BluePass, Bluetooth Stack Smasher, BlueSmack, BlueStab

Submitting a non-standard input for getting different results.

Obfuscation Bdaddr, Spooftooph,

hciconfig

To hide the identity of an attacker.

Range Extension BlueSnipping, Bluetoone

To extend device range for attacking from far distance.

Surveillance

Blueprinting, bt_autdit, Bluefish, Bluescanner, BTScanner

To gather information about the device and the location.

Man-in-the-Middle attack is the most threatening classification where a user is unknowingly connected to a third device instead of connecting to the desired device, giving the access to the user’s data.

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31 Common Bluetooth attacks

The following list shortly explains the most common Bluetooth attacks (Haataja K. et. al, 2013):

 Bluebug: In bluebug attacks, an attacker is be able to get the contacts, call logs, and send/receive messages or even connect to the Internet. It used the device command without any notification to the user.

 BlueSnarf: Bluesnarfing is the process, which allows an attacker to have an access to the device for getting the information like address, calendar information, or even the IMEI (International Mobile Equipment Identity) code of the device, which could be used to route the user’s incoming calls to somewhere else (Suri, P.R, et al., 2008; Tan, M, et al., 2011; Sandhya, S, et al., 2012).

 BlueSnarf++: It is an enhancement of the BlueSnarf, which exposes the devices with full read/write access to the file system.

 Bluejacking: BlueJacking is the process of sending of text messages or anonymous business cards (vCards) to the devices (Bouhenguel, R, et al., 2008;

Karen Scarfone, et al., 2008). However, it is not very serious attack as the hacker cannot get any information from the device.

 Denial-of-Service: The attacker requests the pairing with a Bluetooth device repeatedly but no information is sent to the attacker and the attack can be stopped easily. However, repeated pairing requests could cause the device’s battery to drain and temporarily paralyze the device.

 HeloMoto: It is the combination of BlueSnarf and Bluebug.

 Car Whispering: It is the type of attack, which would allow an attacker to transmit and receive audio signals to and from a car audio system with Bluetooth. An attacker will be able to listen the conversation going inside the car and will also be able to announce something using the car audio.

 Fuzzing attacks: Fuzzing attacks transmit the malformed information to the Bluetooth radio and observe the functionality of the device. It should be understood that the device has a serious vulnerability in the protocol stack if the device is

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slowed or stopped by fuzzing attacks (Bouhenguel, R, et al., 2008; Karen Scarfone, et al., 2008).

 BlueBump: Bluebump can start a trusted connection with the Bluetooth device by sending a business card to make the authentication. The attacker asks the hacked device to delete the link key but does not close the connection. The victim is not aware of the connection and the hacker gets into the device without any authentication by requesting the regeneration of a link key.

 BlueSmack: It is a DoS attack where a large amount of echo requests are sent to the Bluetooth device. When the receiving device continuously receives such repeated requests, the input buffer overflows leading to the segmentation fault and finally causing the device to hang or crash.

 BlueDump: Attacker spoofs one of the device’s address and connects to other devices. In some cases, it causes a stored link key to be dumped, providing the possibility for another pairing with the hacker’s device.

 Bluechop: Bluechop disrupts an established Bluetooth network (piconet) with a device that is not in the network. Since the master device supports multiple connections, an extended network can be created with it. The hacker spoofs the address of some device of the piconet and makes a link to the master device hence disrupting the piconet.

 Blueover: Blueover is intended to serve as an audit tool allowing people to check the vulnerability. It was developed first as a proof-of-concept tool, which can initiate an attack using the mobile phones with J2ME (Java 2 Platform, Micro Edition) platform.

ZigBee

ZigBee is another wireless technology used for communication between the devices over short distances. It is based on IEEE 802.15.4. The best thing about ZigBee is in its design for the low power consumption, which makes its batteries last longer, up to months or even years (Hongwei Li, et al., 2010). It allows the devices to communicate in a variety of network topologies, especially star and hybrid topologies. It supports communication of

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data via unfriendly RF environments, which are quite general in commercial applications.

However, it is much slower than Wi-Fi and Bluetooth.

ZigBee is based on 128-bit AES algorithm providing simple and strong end-to-end security. Zigbee provides security to different layers including MAC layer, network layer, and application layer as well. Its security services include key establishment methods, frame protection and device management services. One of the key drawbacks of security in ZigBee is the high cost of resources (Hongwei Li, et al., 2010).

It provides the possibility to carry out secure communications, protection in establishment and transmission of cryptographic keys, controlling devices and cyphering frames (Hongwei Li, et al., 2010; Maoheng Sun, et al., 2011; Li Chunging et al., 2009). It focuses on the key establishment and distribution, which was not defined in its de-facto standard IEEE 802.15.4.

The specification of ZigBee security has two models. The first one is Standard Security Mode and the second one is High Security Mode. The first security mode is used in the residential applications with low security where as the high security mode is used for commercial applications with higher security.

ZigBee Security

ZigBee security includes encryption, integrity checking, and authentication on its three layers, which are physical (MAC) layer, network (NWK) layer, and application (APS) layer.

These three layers have the responsible of secure transmission of the data. AES-128 encryption is used for the data confidentiality and it uses some security mechanisms from AES algorithm for integrity checking and authentication (Dechuan Chen, et al., 2006; Dini, Gianluca, et al., 2010; Bin Yang, et al., 2009; Meng Qiangian, et al., 2009). These mechanisms can provide services for securing data transmission, device authentication, device management, key establishment, key transport, etc.

MAC layer’s AES encryption algorithm can keep secrecy, integrity, and authenticity. It is

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possible to determine if the MAC frame is encrypted or not by checking the bit on the header of MAC (Sarijari, M.A.B, et al., 2008; Hui Gao, et al., 2009). The MAC layer is responsible for calculating the header data and payload. It then gets a message integrity code to guarantee the data integrity. The frame number is present on the header of every MAC frame, which is used for detecting the missing frames and retransmitting them when needed.

NWK layer is responsible for transmitting messages via multi-hop links. It broadcasts the route requests and processes the received route replies. The NWK layer uses the link key for securing the outgoing NWK frames if link key is available but if not, it uses its active network key for securing the outgoing NWK frames.

ZigBee uses three kind of keys: master keys, network keys, and link keys. Master keys are used as an initial shared secret for Key Establishment Procedure and generating the link keys (Sarijari, M.A.B, et al., 2008; Hui Gao, et al., 2009). Link keys are used to encrypt information between the devices and they are managed in the application level (Dechuan Chen, et al., 2006; Dini, Gianluca, et al., 2010; Bin Yang, et al., 2009; Meng Qiangian, et al., 2009). Network keys are the unique shared 128 bit keys, which are shared to all the devices in the network.

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Figure 10. ZigBee (Sarijari, M.A.B, et al., 2008).

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36 UWB

Ultra-Wideband (UWB) is known for its nice geolocation features, robustness to interference, small-scale fading and its low complexity receivers (Jinyun Zhang, et al., 2009). It is able to provide accurate and very reliable measurement ranges, because of the fine delay resolution and robustness.

It is intended to be used for the high band multimedia links. It can be very useful for the indoor short-range requiring high-speed wireless communication (Pande, D.C, et al., 1999). It provides the bandwidth up to 480 Mbps and can transmit a few Mbps of data at 10 meters distance. It is considered suitable for multimedia applications like streaming audio and videos. UWB can also be used as an unwired replacement of USB 2.0/3.0 and IEEE 1394 standard (Jin-SHyan Lee, et al., 2007). It uses a large spreading factor, which helps in achieving better robustness against the interference and fading. It achieves very low energy consumption and a very simple transmission is made possible because of the short frequencies in impulse radio transmission and a good architectural design. It provides very good advantages for geolocation along with even 10-20 centimeter accuracy due to its bandwidth being proportional to the bandwidth of the precision of ranging measurements forming the basis of good geolocation features (Jinyun Zhang, et al., 2009).

UWB systems are very good option for the tracking applications because of their good time domain resolution and high-resolution localization capacities. One of the very good advantages of UWB is the low loss penetration. That allows the system to penetrate through the obstacles and operate under line-of-sight as well as non-line-of-sight situations. The power consumption of UWB devices is about 10 mW making it a very low power consuming system. UWB devices use a single chip architecture making it a great choice for mobile devices.

One of the issues with the UWB is that it does not provide high resistance to shadowing in the microwave range. However, collaborative communications and appropriate routing could help mitigate the issue. It’s not interfering with other systems in the used

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environments. IEEE developed 802.15.4a standard for UWB based sensor networks that are able to provide high flexibility. Modulation, coding, and a multiple access scheme are being used, allowing either coherent or non-coherent receivers to receive the data.

Environments with different delay spreads can be adapted by UWB (P. Marco, et al., 2011).

It can be greatly used in the hospital locating, tracking, and communication systems. UWB will be able to provide the communication as per the requirements, required location accuracy, and lower cost solution, which will be very helpful in the healthcare industries.

UWB Security

UWB systems are operating below the electro-magnetic noise floor level. This makes the intruders to detect and intercept the transmitting data very difficult. UWB systems are robust against jamming sources as well (Jinyun Zhang, et al., 2009).

Wi-Fi

Wi-Fi is standardized as 802.11 a/b/g/n/ac by IEEE and it is meant for local area networking where a relative high bandwidth is required. The data transfer rate could go up to 6.9 Gbps and has the transmission range of about 300 meters with a normal standard antenna and the range could also be increased with a directional high gain antenna (Huyu Qu, et al., 2009).

It is used very widely these days since its introduction in 1985 as it is the cheapest way to deploy a wireless local area network (Haishen Peng, 2012). It skips the part of heavy cabling, which has always been a problem. Wi-Fi is the most popular wireless network providing the best quality of service along with the security and performance (Joon Hyoung Shim, et al., 2003).

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38 Wi-Fi Security

As Wi-Fi is the most popular and used wireless networking protocol, securing the data over it becomes equally important. Wi-Fi uses Wired Equivalent Privacy (WEP), Wi-Fi Protected Access (WPA), or Wi-Fi Protected Access 2 (WPA2).

WEP is using Rivest Cipher (RC4) algorithm for providing the data confidentiality and CRC-32 is used for the shake of data integrity, but it uses a very simple encryption logic.

WEP encryption is possible to crack within minutes so it is not a safe encryption at all today. It is considered insecure and thus it is not to be used at all (Joon Hyoung Shim, et al., 2003).

WPA was then introduced by the Wi-Fi Alliance. Security enhancements were introduced in WPA for authenticating, access control, message integrity, replay prevention, message privacy, and key distributions. WPA provides the user authentication and it also controls the access with EAP (Extensible Authentication Protocol) and IEEE 802.1x standard is used to provide port-based access control. WPA uses TKIP (Temporal Key Integrity Protocol), which was developed to address the issues seen in WEP.

TKIP makes use of per-packet key, which is able to dynamically generate a new 128 bit key. TKIP is able to defend from replay and weak key attacks (Joon Hyoung Shim, et al., 2003).

WPA supports two operating modes. They are WPA Personal and WPA Enterprise modes. WPA Personal is also called Pre-Shared Key (PSK) as a shared secret key is used for authentication and the user credentials where as WPA Enterprise modes makes use of RADIUS (Remote Authentication Dial-In User Service) protocol for authentication and key distribution (Xiao Luo, 2008).

WEP encryption used an insecure CRC, which was then replaced in WPA with strong message integrity. However, the use of WPA is also limited nowadays, because of the dependency on stream cipher and weak integrity in terms of cryptography.

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WPA2 used AES encryption algorithm with CCMP (Counter Mode with Cipher Block Chaining Message Authentication Code Protocol) in counter mode (Joon Hyoung Shim, et al., 2003). This was the mandatory element defined by IEEE 802.11i standard and it resolved the TKIP security issue found in WPA1. WPA2 is the only security protocol of Wi-Fi without any known or exploited security flaws. (T. Hayajneh, et al., 2015)

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5. DATA ANALYSIS AND COMPARISON

Table 2 provides an overview of data analysis and comparison between Bluetooth, UWB, ZigBee, and Wi-Fi.

Table 2. Data Analysis and Comparison.

Protocol: Bluetooth: UWB: ZigBee: Wi-Fi:

IEEE Standard 802.15.1 802.15.3a 802.15.4 802.11a/b/g/n/ac

Range 10-100 m 10 m 10-100 m 100-300 m

Max signal rate 1-24 Mbps 480 Mbps 250 Kbps 6.9 Gbps

Basic Cell Piconet Piconet Star BSS

Extention of basic cell Scatternet Peer-to-Peer Cluster tree, Mesh ESS

Encryption SAFER+

or AES

AES AES RC4 or AES

Authentication Shared secret

CBC-MAC (CCM) CBC-MAC (ext. of CCM)

WPA2 (802.11i)

Data protection 16-bit CRC 32-bit CRC 16-bit CRC 32-bit CRC

Bluetooth, UWB, and ZigBee are usually meant for the lower range transmission whereas Wi-Fi supports up to 300 meters range of transmission (Bouhenguel, R, et al., 2008;

Karen Scarfone, et al., 2008). Similarly, Bluetooth and ZigBee supports the lower data rate while UWB and Wi-Fi supports much higher data transmission rate.

All the protocols use encryption and authentication mechanisms. Talking about the encryption, Bluetooth used SAFER+ or AES whereas both UWB and ZigBee use AES.

However, Wi-Fi uses RC4 or AES for encryption. People generally use WPA2 security these days because WEP can be cracked very easily (Jin-SHyan Lee, et al., 2007).

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Bluetooth devices use a pre-shared key and a strong encryption mechanism. The strength depends on the length of the randomness of passkeys for pairing. However, the security also depends on the discoverability and the connectivity settings on the devices.

It provided four different modes of security and it also offers optional user authentication, which adds the additional security.

ZigBee uses 128 bit AES algorithm for the encryption. It uses master keys, link keys, and network keys for encrypting and includes methods for key establishment, transport, device management, and frame protection (Dechuan Chen, et al., 2006; Dini, Gianluca, et al., 2010; Bin Yang, et al., 2009; Meng Qiangian, et al., 2009).

UWB is considered very strong in the physical layer security. Many applications are already using the UWB channels for device secret keys.

Wi-Fi is by far, the mostly used wireless protocol and has the best security features as well. Since WEP can be cracked very easily, people use mostly WPA or WPA2 to secure their networks.

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6. CONCLUSION AND FUTURE WORK

Security is an important aspect when it comes to the Tele-health care systems. A compromised system can easily risk the data of the patients and expose the personal information to unwanted hands. Lots of security protocols have been developed to secure the data but many of them seem to have the loopholes and cannot be considered very secure. Therefore, we need to take some countermeasures ourselves to keep the data more secured.

Tele-health care systems use the short-range communication as well as long-range communication for the data transmission. Wi-Fi is the most secured means of communication if properly implemented using the proper encryption. But in case of short- range communication protocols, such as Bluetooth, UWB, and ZigBee, there are more precautions to take before taking the device in use. For example, by setting a Bluetooth device into undiscoverable mode and allowing the pairing to happen only with the known legitimate devices when needed could easily minimize the security risk. Similarly, in case of Wi-Fi, we can keep the Wi-Fi network SSID (Service Set Identifier) hidden so that it at least slows down the attacker.

The future of Tele-health care systems is very promising as the use of these kinds of systems are increasing everyday and helping the patients to fight with their conditions in a very efficient way. With this, the future study of the security requirements in tele-health becomes very important as well. The development of tele-health care systems is using relatively new technologies so there is always a chance for new attacks. There is a clear need to work on the security aspects further to avoid the critical security vulnerabilities.

Bluetooth and WiFi security has improved quite a lot in the last few years, as they are the most widely used technologies. ZigBee and UWB security needs a lot of research and work to be done as they are lagging behind in the security aspects. One of the important future work that can be done is to utilize the security of Bluetooth devices to implement it in ZigBee and UWB. As they are very similar technologies, it would be nice to have one

Data security in telehealth and smart home environment

Master’s Thesis