Robust Password-Protected Secret Sharing

Abstract. Password-protected secret sharing (PPSS) schemes allow a user to publicly share this highentropy 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. In particular, this secret will remain safe as long as not too many servers get corrupted. However, servers are not always reliable and the communication can be altered. To address this issue, a robust PPSS should additionally guarantee that a user can recover his secret as long as enough servers provide correct answers, and these are received without alteration. In this paper, we propose new robust PPSS schemes which are significantly more efficient than the existing ones. We achieve this goal in two steps. First, we introduce a Robust Threshold Secret Sharing Scheme with respect to Random Failures that allows us to drop the verifiable property of Oblivious Pseudorandom Functions. Then, we use this new construction ...

• Type: Journal
• Year: 2016
• Where: IACR
• Authors: Michel Abdalla, Mario Cornejo, Anca Nitulescu, David Pointcheval
• Keywords: Biometrics, IACR 2016