Shin-ya Nishizaki

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We are developing a secure and certified e-mail system AnZenMail that provides an experimental testbed for our cutting-edge security enhancement technologies. In addition to a provably secure message transfer protocol, we have designed and implemented a server (MTU) and a client (MUA) in order that they could survive recent malicious attacks such as(More)
This paper describes a formalization of a class of xed-point problems on graphs and its applications. This class captures several wellknown graph theoretical problems such as those of shortest path type and for data ow analysis. An abstract solution algorithm of the xedpoint problem is formalized and its correctness is proved using a theorem proving system.(More)
Recently, software verification using model checkers has achieved widespread success. It can locate hard-to-find bugs in software by exhaustively searching executing paths. In this paper, we propose a new software design method that enables the evaluation of the fault tolerance of software behavior at the specification level: we can check software behavior,(More)