Research And Implementation Of Secure Communication System For Oma Lightweight Machine-to-Machine

The advent of the Internet of Things communication era makes it possible to connect everything,and the 5G era also poses challenges to new Internet of Things communication methods.Among them,the CoAP defined by the Open Mobile Alliance(OMA)and formulated by the IETF realizes the communication between the LWM2M server and the LWM2M client deployed in restricted IoT devices,and has become a research direction that has attracted much attention.In order to ensure the security of application layer data in UDP communication,IETF proposed the DTLS protocol on the basis of TLS.Although DTLS 1.3 is still in the draft stage,it can be predicted that it will soon become the most widely used version of the DTLS version.The implementation in the mainstream CoAP software environment and the adaptation in the SMS communication environment have become the gaps in the current research field.In order to solve the above problems,this paper designs and implements some of the specifications in the DTLS 1.3 draft based on the Californium framework,and adapts them to the SMS environment.The main contents are as follows:The first part is to implement the DTLS 1.3 draft handshake function,the upper layer is connected to the CoAP protocol,and the lower layer is connected to the UDP protocol.In order to make the transmission efficiency of IoT nodes that use the Californium framework and DTLS to ensure communication security higher,this research implements the DTLS 1.3 version of the handshake protocol and deploys it on Android phones to test the efficiency of the handshake protocol.DTLS 1.2 for comparison.The second part is to implement the control mechanism for the coexistence of DTLS 1.2 and DTLS 1.3 in the Californium framework.Since DTLS 1.2 will coexist with DTLS 1.3,it is extremely necessary to implement a negotiation selection mechanism that supports both versions at the same time.This research implements a communication negotiation mechanism for the coexistence of the two versions of DTLS in the Californium framework,and records whether the versions can be completed negotiation function normally.The third part is the reliability mechanism implemented in the DTLS 1.3 record layer,and studies and evaluates the impact of the acknowledgment retransmission mechanism of the record protocol on SMS communication.In the DTLS 1.3 draft,the reliability mechanism of the record layer is mainly realized by sending and receiving ACK messages.The record layer reliability mechanism of DTLS 1.3 will greatly reduce the size of the data packets that need to be retransmitted in the case of timeout retransmission.It has important significance in the SMS environment.