Abstract
This chapter reports the authors' experiences regarding security of the electronic medical record (EMR). Although the EMR objectives are to support shared care and healthcare professionals' workflow, there are some barriers that prevent its successful use. These barriers comprise not only costs, regarding resources and time, but also patient / health professional relations, ICT (information and communication technologies) education as well as security issues. It is very difficult to evaluate EMR systems; however some studies already made show problems regarding usability and proper healthcare workflow modeling. Legislation to guide the protection of health information systems is also very difficult to implement in practice. This chapter shows that access control, as a part of an EMR, can be a key to minimize some of its barriers, if the means to design, develop and evaluate access control are closer to users' needs and workflow complexity. © 2009, IGI Global.

Abstract
There is no generally accepted definition of conditional Renyi entropy. The (unconditional) Renyi entropy depends on a parameter alpha, which for the case of min-entropy takes the value infinity. Even for this particular case, there are several proposals for the definition of conditional entropy. This paper describes three general definitions of conditional Renyi entropy that were found or suggested in the literature. Their properties are studied and their values, as a function of alpha, are compared. The particular case of min-entropy is widely used in cryptography as a security parameter; this case is studied in some detail.

Abstract
The Electronic Medical Record (EMR) integrates heterogeneous information within a Healthcare Institution stressing the need for security and access control. The Biostatistics and Medical Informatics Department from Porto Faculty of Medicine has recently implemented a Virtual EMR (VEMR) in order to integrate patient information and clinical reports within a university hospital. With more than 500 medical doctors using the system on a daily basis, an access control policy and model were implemented. However, the healthcare environment has unanticipated situations (i.e. emergency situations) where access to information is essential. Most traditional policies do not allow for overriding. A policy that allows for "Break-The-Glass (BTG)" was implemented in order to override access control whilst providing for non-repudiation mechanisms for its usage. The policy was easily integrated within the model confirming its modularity and the fact that user intervention in defining security procedures is crucial to its successful implementation and use.

Abstract
We revisit the notion of computational depth and sophistication for infinite sequences and study the density of the sets of deep and sophisticated infinite sequences. Koppel defined he sophistication of an object as the length of the shortest total program that, given some data as input, produces the object and such that the sum of the size of the program with the size of the data is as concise as the smallest description of the object. However, the notion of sophistication is not properly defined for all sequences. We propose a new definition of sophistication for infinite sequences as the limit of the ratio of the sophistication of the initial segments and its length. We prove that the set of sequences with sophistication equal to zero has Lebesgue measure one and that the set of sophisticated sequences is dense, when the sophistication is, respectively, defined either using lim inf or lim sup. Antunes, Fortnow, van Melkebeek and Vinodchandran captured the notion of useful information by computational depth, the difference between time bounded and unbounded Kolmogorov complexities. We show that the set of deep infinite sequences is dense. We also prove that sophistication and depth for infinite sequences are distinct information measures.

Abstract
Usually one can quantify the subjective notion of useful information in two different perspectives: static resources - measuring the amount of planing required to construct the object; or dynamic resources - measuring the computational effort required to produce the object. We study the robustness of logical depth measuring dynamic resources, proving that small variations in the significance level can cause large changes in the logical depth. © 2012 Springer-Verlag.

Abstract
Patients visit multiple health institutions and leave a trail of information scattered around hospitals, healthcare centres and laboratories. Information availability is of major importance in healthcare delivery. Most of the Electronic Patient Record systems are unarticulated and usually address only the specificities of a single medical specialty. Virtual Electronic Patient Records such as MAID (Multi Agent system for the Integration of Data) system provide for the necessary means for intra-institutions departmental information integration. In this paper is presented a mobile agent based extension to the agent based MAID system in order to enable inter-institution patient data integration. This system was designed as a MAID extension with additional patient data integration features. In order to accomplish this, modules for external data discovery and collection where developed using mobile agents. Data collection activities are trigged by scheduled clinical events. The system is intended to enhance an existing institutional system taking it beyond the institutional barrier providing health professionals with a more complete patient clinical history.