Evolutionary theory predicts that animals act to maximize their fitness when choosing among a set of options, such as what to eat or where to live. Making the best choice is challenging when options vary in multiple attributes, and animals have evolved a variety of heuristics to simplify the task. Many of these involve ranking or weighting attributes according to their importance. Because the i...

Cipher-policy attribute-based encryption (CP-ABE) is a more efficient and flexible encryption system as the encryptor can control the access structure when encrypting a message. In this paper, we propose a privacy-preserving decentralized CP-ABE (PPDCP-ABE) scheme where the central authority is not required, namely each authority can work independently without the cooperation to initialize the ...

The existing model of Federated Identity Management (FIM) allows a user to provide attributes only from a single Identity Provider (IdP) per service session. However, this does not cater to the fact that the user attributes are scattered and stored across multiple IdPs. An attribute aggregation mechanism would allow a user to aggregate attributes from multiple providers and pass them to a Servi...

Cost-based optimizers in relational databases make use of data statistics to estimate intermediate result cardinalities. Those cardinalities are needed to estimate access plan costs in order to choose the cheapest plan for executing a query. Since statistics are usually collected on single attributes only, the optimizer can not directly estimate result cardinalities of conjunctive predicates ov...

It is inadequate to just assure the functional requirements. Quality of service (QoS) must also be satisfied. An important challenge for developing efficient Service Oriented Architecture (SOA) is to maintain the QoS attributes because of compositional and dynamical environment of SOA. It is significant to scrutinize how quality attributes are supported by SOA. However, implementation of SOA pr...