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Publications

Publications by HASLab

2016

Digital Government and Administrative Burden Reduction

Authors
Veiga, L; Janowski, T; Barbosa, LS;

Publication
9TH INTERNATIONAL CONFERENCE ON THEORY AND PRACTICE OF ELECTRONIC GOVERNANCE (ICEGOV 2016)

Abstract
Administrative burden represents the costs to businesses, citizens and the administration itself of complying with government regulations and procedures. The burden tends to increase with new forms of public governance that rely less on direct decisions and actions undertaken by traditional government bureaucracies, and more on government creating and regulating the environment for other, non-state actors to jointly address public needs. Based on the reviews of research and policy literature, this paper explores administrative burden as a policy problem, presents how Digital Government (DG) could be applied to address this problem, and identifies societal adoption, organizational readiness and other conditions under which DG can be an effective tool for Administrative Burden Reduction (ABR). Finally, the paper tracks ABR to the latest Contextualization stage in the DG evolution, and discusses possible development approaches and technological potential of pursuing ABR through DG.

2016

Applying the 3C Model to FLOSS Communities

Authors
Fernandes, S; Barbosa, LS;

Publication
COLLABORATION AND TECHNOLOGY, CRIWG 2016

Abstract
How learning occurs within Free/LibreOpen Source (FLOSS) communities and what is the dynamics of such projects (e.g. the life cycle of such projects) are very relevant questions when considering the use of FLOSS projects in a formal education setting. This paper introduces an approach based on the 3C collaboration model (communication, coordination and cooperation) to represent the collaborative learning dynamics within FLOSS communities. To explore the collaborative learning potential of FLOSS communities a number of questionnaires and interviews to selected FLOSS contributors were run. From this study a 3C collaborative model applicable to FLOSS communities was designed and discussed.

2016

Electronic governance in Portugal: a silent pioneer

Authors
Fernandes, S; Barbosa, LS;

Publication
EGOSE

Abstract

2016

Electronic governance in Portugal

Authors
Fernandes, S; Barbosa, LS;

Publication
Proceedings of the International Conference on Electronic Governance and Open Society Challenges in Eurasia - EGOSE '16

Abstract

2016

Foundations of Hardware-Based Attested Computation and Application to SGX

Authors
Barbosa, M; Portela, B; Scerri, G; Warinschi, B;

Publication
1ST IEEE EUROPEAN SYMPOSIUM ON SECURITY AND PRIVACY

Abstract
Exciting new capabilities of modern trusted hardware technologies allow for the execution of arbitrary code within environments completely isolated from the rest of the system and provide cryptographic mechanisms for securely reporting on these executions to remote parties. Rigorously proving security of protocols that rely on this type of hardware faces two obstacles. The first is to develop models appropriate for the induced trust assumptions (e.g., what is the correct notion of a party when the peer one wishes to communicate with is a specific instance of an an outsourced program). The second is to develop scalable analysis methods, as the inherent stateful nature of the platforms precludes the application of existing modular analysis techniques that require high degrees of independence between the components. We give the first steps in this direction by studying three cryptographic tools which have been commonly associated with this new generation of trusted hardware solutions. Specifically, we provide formal security definitions, generic constructions and security analysis for attested computation, key-exchange for attestation and secure outsourced computation. Our approach is incremental: each of the concepts relies on the previous ones according to an approach that is quasi-modular. For example we show how to build a secure outsourced computation scheme from an arbitrary attestation protocol combined together with a key-exchange and an encryption scheme.

2016

Private Functional Encryption: Indistinguishability-Based Definitions and Constructions from Obfuscation

Authors
Arriaga, A; Barbosa, M; Farshim, P;

Publication
PROGRESS IN CRYPTOLOGY - INDOCRYPT 2016

Abstract
Private functional encryption guarantees that not only the information in ciphertexts is hidden but also the circuits in decryption tokens are protected. A notable use case of this notion is query privacy in searchable encryption. Prior privacy models in the literature were fine-tuned for specific functionalities (namely, identity-based encryption and inner-product encryption), did not model correlations between ciphertexts and decryption tokens, or fell under strong uninstantiability results. We develop a new indistinguishability-based privacy notion that overcomes these limitations and give constructions supporting different circuit classes and meeting varying degrees of security. Obfuscation is a common building block that these constructions share, albeit the obfuscators necessary for each construction are based on different assumptions. In particular, we develop a composable and distributionally secure hyperplane membership obfuscator and use it to build an inner-product encryption scheme that achieves an unprecedented level of privacy, positively answering a question left open by Boneh, Raghu-nathan and Segev (ASIACRYPT 2013) concerning the extension and realization of enhanced security for schemes supporting this functionality.

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