Abstract
Recently, IoT devices such as robots, speakers, domestic electrical appliances and smart devices are provided everywhere for everyone. While their authentication request is quite ubiquitously, namely, an authentication for sharing services, the actual implementations are patchy schemes of variety security policies. In this study, we propose the new authentication scheme for IoT devices without certificate authority which is fast enough as well as secure. The verification algorithm is based on suitable ciphered metric. We define a class of such verifiable encryption and give an example for authentication. Moreover, we show the implementation which keeps perfect secrecy by means of Shannon's theory.