Accessible and usable websites and mobile applications for people with autism spectrum disorders: A comparative study

Accessibility, usability and inclusion represent desirable challenges of current research in the field of universal design: in some cases, these features require adaptive behaviours and specialised customisations, while, in general, it is possible to identify common and hareable guidelines. We focus our attention on hildren with autism spectrum disorders. Many studies show the positive impact of using computer technologies for supporting the lives of these users. Despite that, just a restricted part of the current websites and apps is accessible and usable for people with ASD. In this paper, we present general and shared guidelines and best practices for accessibility and usability for all; and we propose specialised guidelines for designers and developers of websites and mobile applications for users with ASD. We then present a review of many of the existing websites and applications, in order to check which comply with all, or parts of these guidelines

Type-Based Analysis of Generic Key Management APIs

In the past few years, cryptographic key management APIs have been shown to be subject to tricky attacks based on the improper use of cryptographic keys. In fact, real APIs provide mechanisms to declare the intended use of keys but they are not strong enough to provide key security. In this paper, we propose a simple imperative programming language for specifying strongly-typed APIs for the management of symmetric, asymmetric and signing keys. The language requires that type information is stored together with the key but it is independent of the actual low-level implementation. We develop a type-based analysis to prove the preservation of integrity and confidentiality of sensitive keys and we show that our abstraction is expressive enough to code realistic key management APIs

Broadcasting with Mobile Agents in Dynamic Networks

We study the standard communication problem of broadcast for mobile agents moving in a network. The agents move autonomously in the network and can communicate with other agents only when they meet at a node. In this model, broadcast is a communication primitive for information transfer from one agent, the source, to all other agents. Previous studies of this problem were restricted to static networks while, in this paper, we consider the problem in dynamic networks modelled as an evolving graph. The dynamicity of the graph is unknown to the agents; in each round an adversary selects which edges of the graph are available, and an agent can choose to traverse one of the available edges adjacent to its current location. The only restriction on the adversary is that the subgraph of available edges in each round must span all nodes; in other words the evolving graph is constantly connected. The agents have global visibility allowing them to see the location of other agents in the graph and move accordingly. Depending on the topology of the underlying graph, we determine how many agents are necessary and sufficient to solve the broadcast problem in dynamic networks. While two agents plus the source are sufficient for ring networks, much larger teams of agents are necessary for denser graphs such as grid graphs and hypercubes, and finally for complete graphs of n nodes at least n-2 agents plus the source are necessary and sufficient. We show lower bounds on the number of agents and provide some algorithms for solving broadcast using the minimum number of agents, for various topologies

Communication in distributed systems

Dottorato di ricerca in informatica. 10 ciclo. Coordinatori Giancarlo Mauri e Daniele MundiciConsiglio Nazionale delle Ricerche - Biblioteca Centrale - P.le Aldo Moro, 7 Rome; Biblioteca Nazionale Centrale - P.za Cavalleggeri, 1, Florence / CNR - Consiglio Nazionale delle RichercheSIGLEITItal

Secure Key Management Policies in Strand Spaces

Key management is the Achilles heel of cryptography. In recent years, several attacks have been identified due to poor key management or too liberal APIs, which do not provide a policy that precisely determines the intended use of cryptographic keys. In this paper, we have taken advantage of the expressiveness and simplicity of strand spaces, first introduced in 1998 by Joshua Guttman et al., to specify a significant subset of key management APIs. We used the automatic CPSA tool to rediscover, in an extremely clear and effective way, some known attacks. We have therefore defined a generic key management policy model and proved a key secrecy theorem for a typed version of the API. The proof highlighted the necessary requirements of the policy that we formalized through a closure property that, in fact, computes which types a key can take at runtime