1,025,510 research outputs found
Partial Order Reduction for Security Protocols
Security protocols are concurrent processes that communicate using
cryptography with the aim of achieving various security properties. Recent work
on their formal verification has brought procedures and tools for deciding
trace equivalence properties (e.g., anonymity, unlinkability, vote secrecy) for
a bounded number of sessions. However, these procedures are based on a naive
symbolic exploration of all traces of the considered processes which,
unsurprisingly, greatly limits the scalability and practical impact of the
verification tools.
In this paper, we overcome this difficulty by developing partial order
reduction techniques for the verification of security protocols. We provide
reduced transition systems that optimally eliminate redundant traces, and which
are adequate for model-checking trace equivalence properties of protocols by
means of symbolic execution. We have implemented our reductions in the tool
Apte, and demonstrated that it achieves the expected speedup on various
protocols
Aquaculture, fisheries, poverty and food security
Fisheries and aquaculture play important roles in providing food and income in many developing countries, either as a stand-alone activity or in association with crop agriculture and livestock rearing. The aim of this paper is to identify how these contributions of fisheries and aquaculture to poverty reduction and food security can be enhanced while also addressing the need for a sustainability transition in over-exploited and over-capitalized capture fisheries, and for improved environmental performance and distributive justice in a rapidly growing aquaculture sector. The focus of the paper is on the poverty and food security concerns of developing countries, with an emphasis on the least developed. The emphasis is on food security rather than poverty reduction policies and strategies, although the two are of course related. The food security agenda is very much to the fore at present; fish prices rose along with other food prices in 2007-8 and as fish provide important nutritional benefits to the poor, food security has become a primary concern for sector policy
Economic Reforms and Labor Markets: Policy Issues and Lessons from Chile
This paper deals with the reform to labor market regulation implemented by Chile during the last twenty years. We concentrate on the reform to job security, on the decentralization of the wage bargaining process, and on the reduction in payroll taxes. Our interest is to understand to what extent these reforms helped reduce Chile's rate of unemployment from European' to U.S' levels. We argue that the reduction of payroll taxes (within the context of the social security reform), and the decentralization of bargaining increased labor market flexibility and contributed to the reduction of unemployment. Our analysis suggests that the reform on job security had no significant effect on the aggregate rate of unemployment.
Orthogonal-state-based cryptography in quantum mechanics and local post-quantum theories
We introduce the concept of cryptographic reduction, in analogy with a
similar concept in computational complexity theory. In this framework, class
of crypto-protocols reduces to protocol class in a scenario , if for
every instance of , there is an instance of and a secure
transformation that reproduces given , such that the security of
guarantees the security of . Here we employ this reductive framework to
study the relationship between security in quantum key distribution (QKD) and
quantum secure direct communication (QSDC). We show that replacing the
streaming of independent qubits in a QKD scheme by block encoding and
transmission (permuting the order of particles block by block) of qubits, we
can construct a QSDC scheme. This forms the basis for the \textit{block
reduction} from a QSDC class of protocols to a QKD class of protocols, whereby
if the latter is secure, then so is the former. Conversely, given a secure QSDC
protocol, we can of course construct a secure QKD scheme by transmitting a
random key as the direct message. Then the QKD class of protocols is secure,
assuming the security of the QSDC class which it is built from. We refer to
this method of deduction of security for this class of QKD protocols, as
\textit{key reduction}. Finally, we propose an orthogonal-state-based
deterministic key distribution (KD) protocol which is secure in some local
post-quantum theories. Its security arises neither from geographic splitting of
a code state nor from Heisenberg uncertainty, but from post-measurement
disturbance.Comment: 12 pages, no figure, this is a modified version of a talk delivered
by Anirban Pathak at Quantum 2014, INRIM, Turin, Italy. This version is
published in Int. J. Quantum. Info
Some Characteristics of Pro-poor Growth, and Policy Implications for Mozambique
Resultados das investigaçÔes do Departamento de AnĂĄlise de PolĂticas MADER-Direcção de EconomĂafood security, food policy, Mozambique, pro-poor growth, poverty reduction, Agricultural and Food Policy, Food Security and Poverty, Q18,
Aquaculture, fisheries, poverty and food security
Fisheries and aquaculture play important roles in providing food and income in many developing countries, either as a stand-alone activity or in association with crop agriculture and livestock rearing. The aim of this paper is to identify how these contributions of fisheries and aquaculture to poverty reduction and food security can be enhanced while also addressing the need for a sustainability transition in over-exploited and over-capitalized capture fisheries, and for improved environmental performance and distributive justice in a rapidly growing aquaculture sector. The focus of the paper is on the poverty and food security concerns of developing countries, with an emphasis on the least developed. The emphasis is on food security rather than poverty reduction policies and strategies, although the two are of course related. The food security agenda is very much to the fore at present; fish prices rose along with other food prices in 2007-8 and as fish provide important nutritional benefits to the poor, food security has become a primary concern for sector policy.Aquaculture, Food security, Fisheries, Nutrition
Improving governance to eradicate hunger and poverty:
Poverty reduction, Hunger, Governance, food security, Political economy, Policy implications,
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