A Study Of Certificateless Public Cryptography In Internet Of Things

With the rapid development of computer and communication technology,the demand for informatization in society has shown an explosive growth,which leading the direction of advanced technology to Big Data,Cloud Computing,Mobile Internet,Artificial Intelligence,Internet of Things,and Block Chain.Among them,the Internet of Things(Io T)plays an important role in driving force in digital times,it is an important means to realize social information revolution.In consideration of safety and efficiency,we need to conduct research and discussion on the basic security issues of the Io T.The main security issues in the Io T are identity authentication and privacy protection.It is an extension and expansion of traditional Internet security,but more complicated compared to the Internet.In traditional Internet security,it is effective to build public key infrastructure and use digital certificates as an important cryptographic tool for entity identity authentication.In the context of the Io T,the scale of the Io T is too large,and the problem of certificate management caused by a large number of devices is particularly prominent.We urgently need to find a lightweight management solution to replace public key certificates to reduce the burden on managers.At the same time,the capabilities and properties of the various Io T components are quite different.We also need to find lightweight solutions to meet the security needs of the various Io T components while ensuring the efficiency of it.In elliptic curve cryptography,the computation cost of the bilinear pairing can reach 20 times to the point multiplication.For some devices which have limit power supply and computing resources,it is quite difficult to implement the logic of bilinear pairing by code.In this thesis,an improved hierarchical certificateless crypto scheme without bilinear pairing was proposed,which is aimed to solve the cross-domain identity authentication and key agreement for the Io T environment.This solution fully inherits the characteristics of the public key infrastructure supporting cross-domain authentication,and has obvious computing advantages in the hierarchical signature verification process.The design avoids complex bilinear pairing operations,makes the solution universally applicable in the Internet of Things environment,and provides an idea for solving cross-domain problems under the certificateless cryptosystem.At the same time,to solve the increasingly prominent privacy protection problem in Io T,this thesis analyzes the existing two certificateless aggregate signature schemes that support anonymity without bilinear pairing and points out their respective security problems.Based on these,an improved certificateless aggregate signature scheme which supports controllable anonymity was redesigned.It is proved to be secure under the random oracle model,and each scheme was implemented by code in a series of hardware platforms.By comparing the spending time of different schemes on different hardware platforms,the conclusion could be drawn that the new proposed certificateless aggregate signature scheme is more effective compared to these original schemes,and the new one shows a better adaptation to various kind of devices with different computing capabilities in the Io T environment.