Public wireless networks are quite popular and provide the so-called "Free Wi-Fi" services in various places. In order to make the network secure, a user authentication such as the one based on IEEE802.1X needs to be introduced . Although the user authentication is important in terms of security, Service Providers (SPs) cannot ignore the management cost for user accounts. To reduce such cost, there has been a movement for enabling us to use identity federation like eduroam , . On the other hand, when the Great East Japan Earthquake and the accompanying great tsunamis took place in 2011, many people lost communication means due to equipment damages. In such a situation, people suffered from the disaster and required communication means in order to get information about disaster situations and relief supplies. Therefore, the demand of the methods for easier and quicker deployment of Access Points (APs) in disaster areas is high and one of the desired solutions would be to use Wireless Mesh Network (WMN) which does not require wiring work . Any network should need to have appropriate security functions not only in a usual city but also in disaster areas since there may be some attacks by malicious people in any situations. This paper proposes an architecture design for deploying secure and disaster-tolerant WMN system quickly. We explore certificate-based roaming system in this work.