Date: 2008/3/20(Tue) 15:30〜17:00

      Place: Collaboration Room #7 (Information Science Building, 5th floor)

      Name: Yvo Desmedt
      The BT Chair of Information Security at University College London, UK. He is also a courtesy professor at Florida State University.

      Title: Revisiting pairing based group key exchange

      Abstract: We propose new constant round pairing based group authenticated key exchange (AKE) protocols, which require lower computational complexity per user compared to previous proposals. Furthermore, one of our schemes is particularly interesting for groups in which some members enjoy more computational power than others. The protocol is most efficient if these members constitute roughly half of the group. If the parameters are chosen appropriately so that the pairing computations are fast the protocols can outperform traditional Burmester-Desmedt key exchange protocols. (This work is jointly with Tanja Lange and was presented at Financial Crypto 2008.)