Authors
Martín Vigil, Denise Demirel, Sheikh Mahbub Habib, Sascha Hauke, Johannes Buchmann, Max Mühlhäuser (Technische Universität Darmstadt)

Abstract
Digital archiving systems are necessary to store documents for several years, such as electronic health records. However, security breaches in these systems may allow attackers to tamper with archived documents without being noticed. To address this threat, standardized archiving systems require a public key infrastructure, where a time-stamp authority is trusted to date and sign stored documents periodically. However, in practice a time-stamp authority may not be fully trustworthy, allowing an attacker to forge documents. Thus, in this paper, we introduce a novel reputation-based trust system for time-stamping-based archiving called Long-term evaluation of Trust (LoT), which alleviates the required trust assumptions. This makes LoT an important contribution to realize trust and security management for digital archiving systems using public key infrastructures. We implemented LoT showcasing its applicability to electronic health records and demonstrate its efficacy by simulations.

Venue
The Tenth International Conference on Emerging Security Information, Systems and Technologies - SECURWARE 2016, http://www.iaria.org/conferences2016/SECURWARE16.html
Track: Security management

Place and Date
July 24 - 28, 2016 - Nice, France

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Sören Bleikertz (IBM Research - Zurich), Carsten Vogel (IBM Research - Zurich), Thomas Groß (Newcastle University), Sebastian Mödersheim (DTU Compute)

Abstract

The pervasiveness of cloud computing can be attributed to its scale and elasticity. However, the operational complexity of the underlying cloud infrastructure is high, due to its dynamics, multi-tenancy, and size. Misconfigurations and insider attacks carry significant operational and security risks, such as breaches in tenant isolation put both the infrastructure provider and the consumers at risk.We tackle this challenge by establishing a practical security system, called Weatherman, that proactively analyzes changes induced by management operations with respect to security policies. We achieve this by contributing the first formal model of cloud management operations that captures their impact on the infrastructure in the form of graph transformations. Our approach combines such a model of operations with an information flow analysis suited for isolation as well as a policy verifier for a variety of security and operational policies. Our system provides a run-time enforcement of infrastructure security policies, as well as a what-if analysis for change planning.

Venue

2015 Annual Computer Security Applications Conference (ACSAC 31) (https://www.acsac.org/2015/)

Place and Date

Los Angeles, California, USA, December 5th-9th 2015

Publication Reference

Sören Bleikertz, Carsten Vogel, Thomas Groß, Sebastian Mödersheim. "Proactive Security Analysis of Changes in Virtualized Infrastructures", Information Security and Cryptology - ICISC 2015 - 2015 Annual Computer Security Applications Conference, Los Angeles, California, December 5-9, 2015.

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