  Systems using 5G are expected to be used in various cases of Society 5.0 and
Industrie 4.0 such as smart cities, smart factories, and also critical
infrastructures. These systems are essential for our life, thus cyberattacks
against the system must be prevented. In this paper, we tackle two problems
posed by 5G features: system construction using multi-vendor devices and
softwarized functions. Specifically, there are supply-chain risks that
malicious devices are used in the construction phase. Moreover, the softwarized
network functions are easy to be attacked compared to hardware. To cope with
these problems, we propose a concept of architecture comprising a blockchain to
record security events including supply-chain information and a tamper
detection engine to ensure the integrity of software components in 5G system.
We implement the initial prototype of the architecture and show its
feasibility.
