Dynamic PDP vs. Dynamic POR: Are they really different ?

As many services are moving to the cloud, we are losing control of our own data. This constitutes one of the biggest problems that we face in this decade. The talk will start simple, presenting basics of cryptographic mechanisms for security protection of outsourced data. The basics will include data structures, such as rank-based authenticated skip lists, used in dynamic provable data possession (DPDP) schemes. Later, we will switch gears, and talk about dynamic proofs of retrievability (DPOR) schemes. At the technical level, the difference is that the POR-type schemes employ erasure codes. We will see how the first DPOR scheme PORAM is achieved with the help of oblivious RAM, and then informally talk about some latest results on how to achieve DPOR without the full complexity of the oblivious RAM constructions. As a surprise, we will talk about how to achieve DPOR using only static PDP and DPDP, meaning that the first DPOR scheme existed (though no one knew) in 2009 already. Finally, we will conclude with a philosophical discussion of their difference in practice.

Speaker Details

Alptekin Küpçü has received his Ph.D. degree from Brown University Computer Science Department in 2010. Since then, he has been working as an assistant professor at Koç University, and leading the Cryptography, Security & Privacy Research Group he has founded. His research mainly focuses on applied cryptography, and its intersection with cloud security, privacy, peer-to-peer networks, and mechanism design. He has also led the development of the Brownie Cashlib cryptographic library, which is available as open source online. Dr. Küpçü has various accomplishments including 2 patents pending, 6 funded research projects (for 4 of which he was the principal investigator), 2 European Union COST Action management committee memberships, and Koç University Teaching Innovation Grant. For more information, visit http://crypto.ku.edu.tr

Alptekin Kupcu
Koc University
    • Portrait of Jeff Running

      Jeff Running