## 3 Home Area Network
### Smart Home HAN Requirements
#### 3.2.1 Secure Communication  
Home data networks are increasingly exposed to external attacks from the internet. At the same time, near local networks inside or outside of the house may be used to get access to sensitive information such as data metering or to change the dose of diabetic medicine endangering the lives of their residents. This means that the HAN has to authenticate all devices, protect data integrity and privacy (e.g., by encryption) and provide protection against replay attacks; such attacks are a particular concern where the HAN is used to support a security related application (people and/or property). HAN connected devices may have very limited resources to achieve low cost and long battery lifetime. This is the case of wireless HAN tailored for portable devices used, for example, to monitor patient health state or for tracking packages with restrictions such as antibiotics. As for networks based on physical cables, Ethernet enabled devices have enough hardware resources for accomplishing the security issue. Despite the physical and energy constraints advanced security services are expected to be provided by the wireless HAN technology and the platform operators. This is to say, higher level software does not need to implement security measures if the same are provided by the communication protocol. Figure 2: The classification of the main characteristics and requirements for HAN. Security is one of the most significant characteristics of any system. Researchers have different perspective regarding security and it can be defined in many ways, for instance, the US department of commerce defines security as a condition that results from the creation and maintenance of protecting measures that guarantee a state of inviolability from hostile acts or influences [51]. In general, security is a concept similar to safety of the system as a whole. Thus, its intention is to defend HAN area of attacks such as: data modification, impersonation attack, eavesdropping and replaying. The security requirements are:  
Integrity  
It certifies if a message that is being sent reaches the receiver intact. It is important that this is done in an effective and accurate manner. If this does not happen the receiver equipment can be unutilized, damaged or even a message could be sent to the wrong receiver by the source. Falsifying message contents, including the sender's address, has to be detected. The sender of a message must be able to prove that a specific message has been sent and if the receiver has indeed received the message. Nobody can falsify the network operators in terms of usage fees and the network operators can only charge fees for successfully delivered messages. Authentication  
Authentication is known due to its three major aspects. Entity authentication helps to verify the veracity of a claimed or presumed identity of the sender. Data origin authentication verifies the source of the message. Location authentication guarantees the truthfulness of the claimed or presumed location information [52]. This requirement is utilised by one node to identify another node or to verify the source of origin of data in the network. Thus, it is essential for tasks like association, beaconing, parametrization, and sending and/or receiving of critical data for the adequate operation of the involved network's elements. Confidentiality  
Message contents must be kept confidential, which means that only the communication partners may comprehend it. The messages of the sender and/or receiver should be indecipherable for everybody else, and third parties, such as the network operators, should be incapable to perceive their communication. Furthermore, potential communication partners or third parties cannot be capable to locate HAN stations or their users. This can be achieved by generating the information incomprehensible by using cryptographic encryption. As the information travels across the home networks, data must be ensured to prevent non-authorised access from other elements.