Many-to-Many Information Flow Policies

Information flow techniques typically classify information according to suitable security levels and enforce policies that are based on binary relations between individual levels, e.g., stating that information is allowed to flow from one level to another. We argue that some information flow properties of interest naturally require coordination patterns that involve sets of security levels rather than individual levels: some secret information could be safely disclosed to a set of confidential channels of incomparable security levels, with individual leaks considered instead illegal; a group of competing agencies might agree to disclose their secrets, with individual disclosures being undesired, etc. Motivated by this we propose a simple language for expressing information flow policies where the usual admitted flow relation between individual security levels is replaced by a relation between sets of security levels, thus allowing to capture coordinated flows of information. The flow of information is expressed in terms of causal dependencies and the satisfaction of a policy is defined with respect to an event structure that is assumed to capture the causal structure of system computations. We suggest applications to secret exchange protocols, program security and security architectures, and discuss the relation to classic notions of information flow control

Distributed Non-Interference

Information flow security properties were defined some years ago (see, e.g., the surveys \cite{FG01,Ry01}) in terms of suitable equivalence checking problems. These definitions were provided by using sequential models of computations (e.g., labeled transition systems \cite{GV15}), and interleaving behavioral equivalences (e.g., bisimulation equivalence \cite{Mil89}). More recently, the distributed model of Petri nets has been used to study non-interference in \cite{BG03,BG09,BC15}, but also in these papers an interleaving semantics was used. We argue that in order to capture all the relevant information flows, truly-concurrent behavioral equivalences must be used. In particular, we propose for Petri nets the distributed non-interference property, called DNI, based on {\em branching place bisimilarity} \cite{Gor21b}, which is a sensible, decidable equivalence for finite Petri nets with silent moves. Then we focus our attention on the subclass of Petri nets called {\em finite-state machines}, which can be represented (up to isomorphism) by the simple process algebra CFM \cite{Gor17}. DNI is very easily checkable on CFM processes, as it is compositional, so that it does does not suffer from the state-space explosion problem. Moreover, we show that DNI can be characterized syntactically on CFM by means of a type system

Optimization of management information support as a basis for organizational transformations at an enterprise

Increasing of information flows cause the necessity of optimizing their quantity, structure and distribution. In order to eliminate the disadvantages inherent in information systems of electricity delivery enterprises for the processing of internal information, a methodical approach to optimizing document circulation on the basis of modeling with the help of Petri Nets is developed. This article presents a systematic methodology for modeling document circulation flows at enterprise. The constructed model allows to form the structure of the system and the processes taking place in it, to analyze the static state of the system of document circulation and the dynamics of information flows. Also, we described mathematical model of document circulation process, where the central place is occupied by identification and removing of duplicate documents and those that are not processed at each stage of their moving. At final stage we propose to distribute information flows due to specificity of division. For this we need to define and assign information functions to divisions and formalize them considering the rules for processing documents. To determine the extent to which the processing rules of the documents actually go in the subdivision of its main for each transition we introduce the measure of its specificity for subsystem

Estudo de ineficiências na logística externa de empresa produtora de componentes automóveis

A presente dissertação foi desenvolvida durante um período de estágio, em contexto industrial, na empresa FicoCables, que é produtora de componentes como cablagens metálicas e sistemas de conforto para a indústria automóvel. Este trabalho foi incorporado no departamento de logística externa. Em termos gerais, a problemática dos transportes urgentes leva às empresas um custo extra e desnecessário de forma a cumprir os seus compromissos comerciais com os seus clientes. Em grande parte dos casos, deve-se ao facto de lacunas no planeamento. Este caso em particular não é exceção, sendo que, este tipo de custos representa cerca de 33% dos custos totais em transportes, revelando ter um grande impacto económico. Assim sendo, este trabalho surge da necessidade de analisar os transportes a cargo da empresa em estudo, tanto os transportes normais como os transportes urgentes, bem como a melhoria do processo de pedido e gestão de transportes. A caracterização dos transportes normais revelou-se uma tarefa importante pois a partir dela foi desenvolvido um modelo de otimização com o objetivo de maximizar os envios realizados pela empresa. O desenvolvimento do protótipo de uma aplicação para a gestão dos transportes tornou-se uma mais valia para a organização pois permitiu ter uma aplicação “ready-to-code” facilitando e tornando mais rápida a sua implementação. Em termos mais específicos, esta aplicação permitirá um maior controlo dos pedidos de transportes efetuados, bem como a redução do tempo necessário para preenchimento dos formulários de pedido de cotação, a condensação dos dados e documentos relativos ao transporte numa única plataforma, um maior rigor dos dados e, ainda, uma maior monitorização dos transportes. Para a análise dos transportes urgentes foram utilizadas algumas das ferramentas de qualidade de forma a determinar as causas-raiz do problema identificado (elevado custo com transportes urgentes). O uso destas ferramentas, nomeadamente, brainstorming, diagrama de Ishikawa e Cinco Porquês, permite um maior envolvimento por parte dos colaboradores das diferentes áreas e, desta forma, é possível a partilha de conhecimentos e, por consequência, uma análise mais fiável das possíveis causas-raiz do problema, bem como, a implementação de ações para as combater. Com a aplicação das ações identificadas, conseguiu-se uma redução dos custos de transportes urgentes em cerca de 68%.The present dissertation was developed during an internship in an industrial context at Fico Cables, a company responsible for producing components such as bowden cables and comfort systems for the automobile industry. The work developed was integrated in the external logistics department. In general terms, the problem of urgent transports takes companies an extra and unnecessary cost in order to meet their business commitments to their customers. In most cases, it is due to the existence of planning gaps. This particular case is no exception, representing a cost of 33% of the total transport cost, revealing a major economic impact. Therefore, there is the need for examining the transport methods carried out by Fico Cables led to the development of this project. Both normal and urgent transports were reviewed, as well as the improvement of the request process and transport management. The description of normal transportation turned out to be a fundamental task, prompting the development of an optimisation model with the ultimate goal of maximising the shipments made by the company. The program prototype design for the transport management became a surprising asset, allowing the company to have access to a computer app “ready-to-code”, making its implementation swift and straight forward. More specifically, this application will allow a greater control of the transport requests made, as well as a reduction in the time required to fill out the request quotation forms, a condensation of the transport data documents onto a single platform, a greater accuracy of data and better monitoring of the transports. The analysis of urgent transports required the application of a few quality tools in order to determine the identified root cause problem (high cost of urgent transport), followed by actions to minimise the cost impact with urgent transport. The use of this tools, namely, brainstorming, Ishikawa diagram and the Five Whys, allows for a greater involvement by employees from different areas and thus, abling knowledge sharing and, as a result, a more reliable analysis of possible root causes of the problem, as well as the actions needed to counteract it. By implementing the identified actions, urgent transport costs were reduced by about 68%

Many-to-many information flow policies

Information flow techniques typically classify information according to suitable security levels and enforce policies that are based on binary relations between individual levels, e.g., stating that information is allowed to flow from one level to another. We argue that some information flow properties of interest naturally require coordination patterns that involve sets of security levels rather than individual levels: some secret information could be safely disclosed to a set of confidential channels of incomparable security levels, with individual leaks considered instead illegal; a group of competing agencies might agree to disclose their secrets, with individual disclosures being undesired, etc. Motivated by this, we study a semantic foundation for such properties based on causal models of computation. We propose a simple language for expressing information flow policies where the usual admitted flow relation between individual security levels is replaced by a relation between sets of security levels, thus allowing to capture coordinated flows of information. The flow of information is expressed in terms of causal dependencies and the satisfaction of a policy is defined with respect to an event structure that is assumed to capture the causal structure of system computations. We also preliminarily explore possibilities for practical applicability of our approach by focusing on systems specified as safe Petri nets, a formalism with a well-established causal semantics. We show how unfolding-based verification techniques for Petri nets can be adopted for solving the problem of checking policy satisfaction