The Internet of Things (IoT) implicates an infrastructure that creates new value by connecting everything with communication networks, and its construction is rapidly progressing in anticipation of its great potential. Enhancing the security of IoT is an essential requirement for supporting IoT. For ensuring IoT security, it is desirable to create a situation that even a terminal component device with many restrictions in computing power and energy capacity can easily verify other devices and data and communicate securely by the use of public key cryptography. To concretely achieve the big goal of penetrating public key cryptographic technology to most IoT end devices, we elaborated the secure cryptographic unit (SCU) built in a low-end microcontroller chip. The SCU comprises a hardware cryptographic engine and a built-in access controlling functionality consisting of a software gate and hardware gate. This paper describes the outline of our SCU construction technology's research and development and prospects.

In this paper, a multiplication algorithm in extension field Fpm is proposed. Different from the previous works, the proposed algorithm can be applied for an arbitrary pair of characteristic p and extension degree m only except for the case when 4p divides m(p-1) and m is an even number. As written in the title, when p>m, 4p does not divide m(p-1). The proposed algorithm is derived by modifying cyclic vector multiplication algorithm (CVMA). We adopt a special class of Gauss period normal bases. At first in this paper, it is formulated as an algorithm and the calculation cost of the modified algorithm is evaluated. Then, compared to those of the previous works, some experimental results are shown. Finally, it is shown that the proposed algorithm is sufficient practical when extension degree m is small.

This paper proposes a public-key cryptography by applying RSA and Petri nets. We introduce RSA and a Petri net based private-key cryptography and then taking the advantages of these two cryptography, we propose a new public-key cryptography, PNPKC. To compare with RSA on security as well as computation order, we do simulation experiments. As the results, the security of PNPKC is as strong as RSA cryptography, and the encryption and decryption of PNPKC are in average 239 times as fast as RSA cryptography from our experiments. Besides, to see if our current PNPKC program can be practically used, we do comparative experiment with PGP, which shows PNPKC takes computation time in average as much as 36 times of PGP cryptography. That means our PNPKC program still needs to be technically improved.

Modern cryptology was born in the late seventies and developed in the eighties. A decade since 1991 is the period of continuation of the development and new expansion of cryptology. In this paper we survey the development of cryptologic researches in this decade with emphasis on the results in Japan. We also present some future important works and propose the foundation of a public institution for evaluation of information security techniques.