97,675 research outputs found
Designing Normative Theories for Ethical and Legal Reasoning: LogiKEy Framework, Methodology, and Tool Support
A framework and methodology---termed LogiKEy---for the design and engineering
of ethical reasoners, normative theories and deontic logics is presented. The
overall motivation is the development of suitable means for the control and
governance of intelligent autonomous systems. LogiKEy's unifying formal
framework is based on semantical embeddings of deontic logics, logic
combinations and ethico-legal domain theories in expressive classic
higher-order logic (HOL). This meta-logical approach enables the provision of
powerful tool support in LogiKEy: off-the-shelf theorem provers and model
finders for HOL are assisting the LogiKEy designer of ethical intelligent
agents to flexibly experiment with underlying logics and their combinations,
with ethico-legal domain theories, and with concrete examples---all at the same
time. Continuous improvements of these off-the-shelf provers, without further
ado, leverage the reasoning performance in LogiKEy. Case studies, in which the
LogiKEy framework and methodology has been applied and tested, give evidence
that HOL's undecidability often does not hinder efficient experimentation.Comment: 50 pages; 10 figure
Securing open multi-agent systems governed by electronic institutions
One way to build large-scale autonomous systems is to develop an open multi-agent system
using peer-to-peer architectures in which agents are not pre-engineered to work together and in
which agents themselves determine the social norms that govern collective behaviour. The social
norms and the agent interaction models can be described by Electronic Institutions such as those
expressed in the Lightweight Coordination Calculus (LCC), a compact executable specification
language based on logic programming and pi-calculus. Open multi-agent systems have
experienced growing popularity in the multi-agent community and are expected to have many
applications in the near future as large scale distributed systems become more widespread, e.g.
in emergency response, electronic commerce and cloud computing. A major practical limitation
to such systems is security, because the very openness of such systems opens the doors to
adversaries for exploit existing vulnerabilities.
This thesis addresses the security of open multi-agent systems governed by electronic
institutions. First, the main forms of attack on open multi-agent systems are introduced and
classified in the proposed attack taxonomy. Then, various security techniques from the literature
are surveyed and analysed. These techniques are categorised as either prevention or detection
approaches. Appropriate countermeasures to each class of attack are also suggested.
A fundamental limitation of conventional security mechanisms (e.g. access control and
encryption) is the inability to prevent information from being propagated. Focusing on
information leakage in choreography systems using LCC, we then suggest two frameworks to
detect insecure information flows: conceptual modeling of interaction models and language-based
information flow analysis. A novel security-typed LCC language is proposed to address
the latter approach.
Both static (design-time) and dynamic (run-time) security type checking are employed to
guarantee no information leakage can occur in annotated LCC interaction models. The proposed
security type system is then formally evaluated by proving its properties. A limitation of both
conceptual modeling and language-based frameworks is difficulty of formalising realistic
policies using annotations.
Finally, the proposed security-typed LCC is applied to a cloud computing configuration case
study, in which virtual machine migration is managed. The secrecy of LCC interaction models
for virtual machine management is analysed and information leaks are discussed
Proving soundness of combinatorial Vickrey auctions and generating verified executable code
Using mechanised reasoning we prove that combinatorial Vickrey auctions are
soundly specified in that they associate a unique outcome (allocation and
transfers) to any valid input (bids). Having done so, we auto-generate verified
executable code from the formally defined auction. This removes a source of
error in implementing the auction design. We intend to use formal methods to
verify new auction designs. Here, our contribution is to introduce and
demonstrate the use of formal methods for auction verification in the familiar
setting of a well-known auction
An Introduction to Mechanized Reasoning
Mechanized reasoning uses computers to verify proofs and to help discover new
theorems. Computer scientists have applied mechanized reasoning to economic
problems but -- to date -- this work has not yet been properly presented in
economics journals. We introduce mechanized reasoning to economists in three
ways. First, we introduce mechanized reasoning in general, describing both the
techniques and their successful applications. Second, we explain how mechanized
reasoning has been applied to economic problems, concentrating on the two
domains that have attracted the most attention: social choice theory and
auction theory. Finally, we present a detailed example of mechanized reasoning
in practice by means of a proof of Vickrey's familiar theorem on second-price
auctions
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