Secure Cloud Storage in Android Devices

110 Pages·2017·3.79 MB·English

Secure Cloud
Storage in Android
Devices
PPaauulloo AAlleexxaannddrree CCaarrvvaallhhoo RRiibbeeiirroo
Master’s Degree in Network and Information Systems Engineering
DDeeppaarrttaammeennttooddeeCCiiêênncciiaaddeeCCoommppuuttaaddoorreess
2017
Orientador
SSéérrggiiooCCrriissóóssttoommoo,ProfessorAuxiliar,
FFaaccuullddaaddeeddeeCCiiêêcciiaassddaaUUnniivveerrssiiddaaddeeddooPPoorrttoo
Coorientador
RRuuiiPPrriioorr,ProfessorAuxiliar,
FFaaccuullddaaddeeddeeCCiiêêcciiaassddaaUUnniivveerrssiiddaaddeeddooPPoorrttoo

Todasascorreçõesdeterminadas
pelojúri,esóessas,foramefetuadas.
OPresidentedoJúri,
Porto, / /

Dedicado aos meus pais, à minha namorada Filipa Crespo e ao meu avô Manuel Veloso
de Carvalho.
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Acknowledgments
I would first like to express my sincere gratitude to my supervisors, Prof. Rui Prior and Prof.
Sérgio Crisóstomo, for all of their support, time and advice. They always allowed this paper to be
my own work, but steered me in the right direction whenever I needed it.
I would also like to thank my friends for all the good moments during this years.
Finally, I must express my very profound gratitude to my parents and to my girlfriend for providing
me with unfailing support and continuous encouragement throughout my years of study and
through the process of researching and writing this thesis. This accomplishment would not have
been possible without them.
Thank you.
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Abstract
Digital data storage is essential nowadays. We store all types of data in our devices, either locally
or using cloud storage services. Cloud services have several advantages, such as data sharing
among devices, space saving in local storage, and data preservation in case of devices hardware
failure. However, they also pose some risks, which users often do not realize, such as temporary
or permanent unavailability or loss of confidentiality of the stored files. This work consists on
the development of a secure file storage system based on public cloud services that mitigate the
mentioned risks by combining the use of multiple cloud providers with redundancy mechanisms
and cryptographic techniques. The system ensures that, even if one provider is hostile or goes
out of business, there is no loss of data or confidentiality.
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