## 2 Related Work
The authors have used DTLS in combination with other standard protocols such as RSA. The use of RSA adds a high computational complexity and overhead to the network. In addition to that, the authentication handshake process in DTLS in which the client and server authenticate each other takes in excess of three round trips. Authors of [20] have suggested a technique for lightweight authentication using Advanced Encryption Standard (AES). In this tech \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Protocol** &
\begin{tabular}{c} **Bytes per** \\ **Transaction** \\ \end{tabular} & **Power** & **Life Time** \\ \hline HTTP & 1451 & 1.333 mW & 84 days \\ CoAP & 154 & 0.744 mW & 151 days \\ \hline \hline \end{tabular}
\end{table} 
Table 1: HTTP and CoAP comparison based on resource consumption. nique, the client and server ensure the identity of the devices based on the message payload. During this process, a total of four messages are exchanged between the client and server. In [21] [PERSON] et al. have presented an implementation of an architecture that uses a delegation method to send and receive messages. In this implementation, a Secure Service Manager (SSM) is used in the handshake process. This system requires the SSM, sensors and trust manager to be located in a constrained network. Hence it may not be suitable for all kinds of IoT setups. In [22], [PERSON] et al. propose a plan for end-to-end security by using DTLS algorithm. This system uses the Elliptic Curve Cryptography (ECC) to encrypt data in resource constrained nodes. Although ECC consumes less power and memory compared to other public key encryption algorithms, it still uses up more resources than the symmetric key encryption algorithms [23]. Using complex cipher suites for encryption results in high energy consumption. The authors have used a symmetric key cryptography algorithm, AES to replace DTLS in the authentication process. AES performs a four-way handshake between the CoAP based server and CoAP client. This process adds two header options in the CoAP packet for enabling secure mode. In [24], the authors present a scheme for the authentication between client and server by modifying the header of the CoAP packets. AES 128 is used for the encryption process and UDP protocol is used without DTLS in the transport layer. This scheme reduces the number of messages required for authentication between two parties without any loss in the overall efficiency. In [25], the various advantages of the new features of \"Future Internet\" are described, which greatly benefits farm management techniques. The \"Future Internet\" programme overcomes the limitations of the already existing Internet. These benefits include generic software modules that can be modified to build specific modules related to farming. The main architecture of the farm management system is specified, depending on which model is stored in the cloud. [PERSON] et al. [26] the main focus of this paper is to protect and secure agricultural goods from rodents and insects in storage units and fields. Real-time security systems are used, which provide notifications as soon as an issue is identified. Python scripts are used to integrate the various electronic devices and sensors. The algorithm of this system is based on data collection to achieve accuracy in alerting the user and starting the repellent. The system is tested in a 10 m\({}^{2}\), the device is fixed in a corner during the testing. As the PIR sensor senses heat, it immediately starts the URD sensor and starts video recording through a webcam. The accuracy achieved from these test cases reaches up to 84.8%. It will be beneficial to incorporate the security system in storage units to prevent rodents from attacking the goods. [PERSON] et al. [27] this paper emphasizes on the role of greenhouse technology in the agricultural field and presents the design and development of an environment monitoring system. This system makes use of ZigBee technology and CC2530 chip.