39,829 research outputs found
Building Confidential and Efficient Query Services in the Cloud with RASP Data Perturbation
With the wide deployment of public cloud computing infrastructures, using
clouds to host data query services has become an appealing solution for the
advantages on scalability and cost-saving. However, some data might be
sensitive that the data owner does not want to move to the cloud unless the
data confidentiality and query privacy are guaranteed. On the other hand, a
secured query service should still provide efficient query processing and
significantly reduce the in-house workload to fully realize the benefits of
cloud computing. We propose the RASP data perturbation method to provide secure
and efficient range query and kNN query services for protected data in the
cloud. The RASP data perturbation method combines order preserving encryption,
dimensionality expansion, random noise injection, and random projection, to
provide strong resilience to attacks on the perturbed data and queries. It also
preserves multidimensional ranges, which allows existing indexing techniques to
be applied to speedup range query processing. The kNN-R algorithm is designed
to work with the RASP range query algorithm to process the kNN queries. We have
carefully analyzed the attacks on data and queries under a precisely defined
threat model and realistic security assumptions. Extensive experiments have
been conducted to show the advantages of this approach on efficiency and
security.Comment: 18 pages, to appear in IEEE TKDE, accepted in December 201
On Properties of Policy-Based Specifications
The advent of large-scale, complex computing systems has dramatically
increased the difficulties of securing accesses to systems' resources. To
ensure confidentiality and integrity, the exploitation of access control
mechanisms has thus become a crucial issue in the design of modern computing
systems. Among the different access control approaches proposed in the last
decades, the policy-based one permits to capture, by resorting to the concept
of attribute, all systems' security-relevant information and to be, at the same
time, sufficiently flexible and expressive to represent the other approaches.
In this paper, we move a step further to understand the effectiveness of
policy-based specifications by studying how they permit to enforce traditional
security properties. To support system designers in developing and maintaining
policy-based specifications, we formalise also some relevant properties
regarding the structure of policies. By means of a case study from the banking
domain, we present real instances of such properties and outline an approach
towards their automatised verification.Comment: In Proceedings WWV 2015, arXiv:1508.0338
Data DNA: The Next Generation of Statistical Metadata
Describes the components of a complete statistical metadata system and suggests ways to create and structure metadata for better access and understanding of data sets by diverse users
Soft Constraint Programming to Analysing Security Protocols
Security protocols stipulate how the remote principals of a computer network
should interact in order to obtain specific security goals. The crucial goals
of confidentiality and authentication may be achieved in various forms, each of
different strength. Using soft (rather than crisp) constraints, we develop a
uniform formal notion for the two goals. They are no longer formalised as mere
yes/no properties as in the existing literature, but gain an extra parameter,
the security level. For example, different messages can enjoy different levels
of confidentiality, or a principal can achieve different levels of
authentication with different principals.
The goals are formalised within a general framework for protocol analysis
that is amenable to mechanisation by model checking. Following the application
of the framework to analysing the asymmetric Needham-Schroeder protocol, we
have recently discovered a new attack on that protocol as a form of retaliation
by principals who have been attacked previously. Having commented on that
attack, we then demonstrate the framework on a bigger, largely deployed
protocol consisting of three phases, Kerberos.Comment: 29 pages, To appear in Theory and Practice of Logic Programming
(TPLP) Paper for Special Issue (Verification and Computational Logic
Quantitative analysis of the leakage of confidential data
Basic information theory is used to analyse the amount of confidential information which may be leaked by programs written in a very simple imperative language. In particular, a detailed analysis is given of the possible leakage due to equality tests and if statements. The analysis is presented as a set of syntax-directed inference rules and can readily be automated
Compiling and securing cryptographic protocols
Protocol narrations are widely used in security as semi-formal notations to
specify conversations between roles. We define a translation from a protocol
narration to the sequences of operations to be performed by each role. Unlike
previous works, we reduce this compilation process to well-known decision
problems in formal protocol analysis. This allows one to define a natural
notion of prudent translation and to reuse many known results from the
literature in order to cover more crypto-primitives. In particular this work is
the first one to show how to compile protocols parameterised by the properties
of the available operations.Comment: A short version was submitted to IP
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