Serviço de autenticação resiliente

U NIVERSIDADE DE L ISBOA
Faculdade de Ciˆencias
Departamento de Inform´atica

RESILIENT AUTHENTICATION SERVICE

Oleksandr Malichevskyy

˜
DISSERTAC
¸ AO

´
MESTRADO EM ENGENHARIA INFORMATICA
Especializac¸a˜ o em Sistemas de Informac¸a˜ o

2013

U NIVERSIDADE DE L ISBOA
Faculdade de Ciˆencias
Departamento de Inform´atica

RESILIENT AUTHENTICATION SERVICE

Oleksandr Malichevskyy

˜
DISSERTAC
¸ AO

Projecto orientado pelo Prof. Doutor Alysson Neves Bessani e co-orientado pelo Prof. Doutor Marcelo Pasin

´
MESTRADO EM ENGENHARIA INFORMATICA
Especializac¸a˜ o em Sistemas de Informac¸a˜ o

2013

Acknowledgments

Initially, I would like to thank my advisers, Professors Marcelo Pasin and Alysson
Bessani, for all lessons given to me day after day.
I also thanks to my colleagues in the Navigators research group and the LaSIGE, and to all my professors from master and undergraduate courses by all the teaching on computer science and regarding life. Special thanks to Diego Kreutz that during this work was always presents to help and advice. So I can say he was my third supervisor.
Last but not least, I would like thank all my family by their unconditional support, patience and encouragement even I being physically away most of the time.
Finally, I would like to thank Jo˜ao Sousa for help in use of BFT-SMaRt library and
Typhon.
This work is partially supported by the European Commission through the project SecFuNet (STREP 288349, FP7-ICT-2011-EU-Brazil) and FCT through multiyear programs
(LaSIGE) and CMUPORTUGAL and CloudFIT (PTDC/EIACCO/108299/2008).

iii

Dedico este trabalho aos Navigators.

Resumo

A grande maioria dos sistemas on-line dependem dos servic¸os b´asicos de autenticac¸a˜ o e autorizac¸a˜ o. Estes s˜ao respons´aveis por prover os recursos necess´arios para evitar acessos indevidos ou n˜ao autorizados a aplicac¸o˜ es, dados ou redes. Para aceder aos recursos por norma os utilizadores usam um nome de utilizador e uma prova, que geralmente e´ uma senha, ou