Ruizhong Wei

Sai Swaroop Madugula, Ruizhong Wei

In this paper, we propose a simple enhancement for the passkey entry protocol in the authentication stage 1 of Secure Simple Pairing using preexisting cryptographic hash functions and random integer generation present in the protocol. The new protocol is more secure and efficient than previous known protocols. Our research mainly focuses on strengthening the passkey entry protocol and protecting the devices against passive eavesdropping and active Man-in-the-middle (MITM) attacks in both Bluetooth Basic Rate/Enhanced Data Rate (BR/EDR) and Bluetooth Low Energy (Bluetooth LE). This method can be used for any device which uses the passkey entry protocol.

Douglas R. Stinson, Ruizhong Wei

In this paper, we consider methods whereby a subset of players in a $(k,n)$-threshold scheme can "repair" another player's share in the event that their share has been lost or corrupted. This will take place without the participation of the dealer who set up the scheme. The repairing protocol should not compromise the (unconditional) security of the threshold scheme, and it should be efficient, where efficiency is measured in terms of the amount of information exchanged during the repairing process. We study two approaches to repairing. The first method is based on the "enrollment protocol" from \cite{NSG} which was originally developed to add a new player to a threshold scheme (without the participation of the dealer) after the scheme was set up. The second method distributes "multiple shares" to each player, as defined by a suitable combinatorial design. This method results in larger shares, but lower communication complexity, as compared to the first method.