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Security for the cloud

Abstract : Cryptography has been a key factor in enabling services and products trading over the Internet. Cloud computing has expanded this revolution and it has become a highly demanded service or utility due to the advantages of high computing power, cheap cost of services, high performance, scalability, accessibility as well as availability. Along with the rise of new businesses, protocols for secure computation have as well emerged. The goal of this thesis is to contribute in the direction of securing existing Internet protocols by providing an analysis of the sources of randomness of these protocols and to introduce better protocols for cloud computing environments. We propose new constructions, improving the efficiency of current solutions in order to make them more accessible and practical. We provide a detailed security analysis for each scheme under reasonable assumptions. We study the security in a cloud computing environment in different levels. On one hand, we formalize a framework to study some popular real-life pseudorandom number generators used in almost every cryptographic application. On the other, we propose two efficient applications for cloud computing. The first allows a user to publicly share its high-entropy secret across different servers and to later recover it by interacting with some of these servers using only his password without requiring any authenticated data. The second, allows a client to securely outsource to a server an encrypted database that can be searched and modified later.
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Submitted on : Thursday, April 5, 2018 - 9:09:07 AM
Last modification on : Wednesday, October 14, 2020 - 4:21:11 AM


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  • HAL Id : tel-01399914, version 2



Mario Cornejo-Ramirez. Security for the cloud. Cryptography and Security [cs.CR]. Université Paris sciences et lettres, 2016. English. ⟨NNT : 2016PSLEE049⟩. ⟨tel-01399914v2⟩