Lightweight Datagram Encryption And New Block-based Agile Authentication Mechanism

With the continuous development and popularization of information technology and network communication,embedded,and Internet of Things devices are widely used in people’s production and life.However,while bringing convenience,the information security of many devices under the local area network has also been threatened.The identity authentication,datagram encryption,access and other operations of multi-node IoT devices in local area networks put forward higher requirements for security.How to solve the rapid authentication and datagram lightweight encryption in the local multi-node IoT environment has become an important research direction.This thesis analyzes the current research status of IoT devices and communication methods under the current network system,focusing on lightweight encryption and block-based authentication key technologies for dedicated IoT networks with weak computing power and numerous nodes.The main work content is as follows:(1)A block-based agile authentication mechanism is proposed,which uses the storage capacity of multiple nodes in the local area network to cache the verified self-signed digital certificates in a distributed manner.It reduces the computational pressure of nodes through efficient communication capabilities in the local area network.Based on the ElGamal digital certificate scheme,the certificate establishment and verification rules are formulated.The hardware fingerprints of the node devices in the network are collected,and the unique number is specified.The Othello Hashing certificate locator is designed and managed uniformly by chain rules.The node location of the cached certificate can be quickly found by two array lookups and one XOR operation.For this authentication mechanism,the Beta trust evaluation principle is applied here to identify malicious devives quickly.(2)Aiming at the shortcomings of the single round key update principle in the TEA encryption algorithm,a new round key update algorithm is proposed.The round key is randomly selected in the group key interval based on the timestamp to improve the single key update principle.A lightweight AES encryption algorithm improvement scheme for embedded devices is proposed.The lightweight improvement of AES is carried out by using a look-up table and merge linear operation.The encryption efficiency is further improved by using accelerated memory access for embedded devices.(3)The local multi-node IoT communication engineering prototype is constructed,and the block-based agile authentication mechanism and improved encryption algorithm proposed in this thesis are tested and evaluated.The nodes in the platform are developed in client/server mode based on ARM architecture.The transmission layer and application layer adopt TCP/IP and MQTT communication protocols,and the auxiliary server is set to record relevant data.In this thesis,experiments are carried out many times in the range of 64-1000 nodes,32-512 KB cache pool size,and 5-10/min certificate application frequency.The results show that the block-based agile authentication mechanism can improve authentication efficiency by more than 38%and significantly save computing costs.In this thesis,TTEA and lightweight AES encryption algorithms are tested.The results show that TTEA can improve the avalanche effect of the TEA algorithm by 50%without increasing the computational complexity of the TEA algorithm,and the lightweight scheme of the AES algorithm can improve the efficiency by 15.02%.This thesis studies and conducts experiments on the identity authentication and datagram encryption communication of the local Internet of Things,and provides some reference for future research on the Internet of Things and communication security.