63,510 research outputs found
Encrypted Shared Data Spaces
The deployment of Share Data Spaces in open, possibly hostile, environments arises the need of protecting the confidentiality of the data space content. Existing approaches focus on access control mechanisms that protect the data space from untrusted agents. The basic assumption is that the hosts (and their administrators) where the data space is deployed have to be trusted. Encryption schemes can be used to protect the data space content from malicious hosts. However, these schemes do not allow searching on encrypted data. In this paper we present a novel encryption scheme that allows tuple matching on completely encrypted tuples. Since the data space does not need to decrypt tuples to perform the search, tuple confidentiality can be guaranteed even when the data space is deployed on malicious hosts (or an adversary gains access to the host). Our scheme does not require authorised agents to share keys for inserting and retrieving tuples. Each authorised agent can encrypt, decrypt, and search encrypted tuples without having to know other agentsā keys. This is beneficial inasmuch as it simplifies the task of key management. An implementation of an encrypted data space based on this scheme is described and some preliminary performance results are given
Autonomic management of multiple non-functional concerns in behavioural skeletons
We introduce and address the problem of concurrent autonomic management of
different non-functional concerns in parallel applications build as a
hierarchical composition of behavioural skeletons. We first define the problems
arising when multiple concerns are dealt with by independent managers, then we
propose a methodology supporting coordinated management, and finally we discuss
how autonomic management of multiple concerns may be implemented in a typical
use case. The paper concludes with an outline of the challenges involved in
realizing the proposed methodology on distributed target architectures such as
clusters and grids. Being based on the behavioural skeleton concept proposed in
the CoreGRID GCM, it is anticipated that the methodology will be readily
integrated into the current reference implementation of GCM based on Java
ProActive and running on top of major grid middleware systems.Comment: 20 pages + cover pag
Masquerade attack detection through observation planning for multi-robot systems
The increasing adoption of autonomous mobile robots comes with
a rising concern over the security of these systems. In this work, we
examine the dangers that an adversary could pose in a multi-agent
robot system. We show that conventional multi-agent plans are
vulnerable to strong attackers masquerading as a properly functioning
agent. We propose a novel technique to incorporate attack
detection into the multi-agent path-finding problem through the
simultaneous synthesis of observation plans. We show that by
specially crafting the multi-agent plan, the induced inter-agent
observations can provide introspective monitoring guarantees; we
achieve guarantees that any adversarial agent that plans to break
the system-wide security specification must necessarily violate the
induced observation plan.Accepted manuscrip
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