arXiv subjects

Takeshi Takahashi

Publications and source records attributed to Takeshi Takahashi.

21 records · Page 2Linked to original sources

arXiv2014

Ontological Approach toward Cybersecurity in Cloud Computing

Widespread deployment of the Internet enabled building of an emerging IT delivery model, i.e., cloud computing. Albeit cloud computing-based services have rapidly developed, their security aspects are still at the initial stage of development. In order to preserve cybersecurity in cloud computing, cybersecurity information that will be exchanged within it needs to be identified and discussed. For this purpose, we propose an ontological approach to cybersecurity in cloud computing. We build an ontology for cybersecurity operational information based on actual cybersecurity operations mainly focused on non-cloud computing. In order to discuss necessary cybersecurity information in cloud computing, we apply the ontology to cloud computing. Through the discussion, we identify essential changes in cloud computing such as data-asset decoupling and clarify the cybersecurity information required by the changes such as data provenance and resource dependency information.

cs.CR↗

arXiv2014

Tailored Security: Building Nonrepudiable Security Service-Level Agreements

The security features of current digital services are mostly defined and dictated by the service provider (SP). A user can always decline to use a service whose terms do not fulfill the expected criteria, but in many cases, even a simple negotiation might result in a more satisfying outcome. This article aims at building nonrepudiable security service-level agreements (SSLAs) between a user and an SP. The proposed mechanism provides a means to describe security requirements and capabilities in different dimensions, from overall targets and risks to technical specifications, and it also helps in translating between the dimensions. A negotiation protocol and a decision algorithm are then used to let the parties agree on the security features used in the service. This article demonstrates the feasibility and usability of the mechanism by describing its usage scenario and proof-of-concept implementation and analyzes its nonrepudiability and security aspects.

cs.CR↗

arXiv2009

Galois points for a normal hypersurface

We study Galois points for a hypersurface $X$ with $\dim {\rm Sing}(X) \le \dim X-2$. The purpose of this article is to determine the set $Δ(X)$ of Galois points in characteristic zero: Indeed, we give a sharp upper bound of the number of Galois points in terms of $\dim X$ and $\dim {\rm Sing}(X)$ if $Δ(X)$ is a finite set, and prove that $X$ is a cone if $Δ(X)$ is infinite. To achieve our purpose, we need a certain hyperplane section theorem on Galois point. We prove this theorem in arbitrary characteristic. On the other hand, the hyperplane section theorem has other important applications: For example, we can classify the Galois group induced from a Galois point in arbitrary characteristic and determine the distribution of Galois points for a Fermat hypersurface of degree $p^e+1$ in characteristic $p>0$.

math.AG↗