Presentation on theme: "Pairwise Key Agreement in Broadcasting Networks - 2005.11.11 - Ik Rae Jeong."— Presentation transcript:
Pairwise Key Agreement in Broadcasting Networks - 2005.11.11 - Ik Rae Jeong
Contents I.Security Notions of Key Exchange II.Type of Networks III.Key Agreement for Key Graphs
I.Security Notions of Key Exchange IA (Implicit Authentication) –Only a designated party can calculate the same session key. Dishonest parties can not get any information about the session key. KI (Key Independence) –security against Denning-Sacco attacks (known key attacks) –for the cases when other session keys are revealed FS (Forward Secrecy) –for the cases when long-term secrets are revealed
II.Types of Network half-duplex full-duplex 4 Rounds 2 Rounds Alice Bob Alice Bob
Session Identifier The unique string per session Used to define matching session in the definition of security of key exchange In the full-duplex channel: the message concatenation by the ordering of owners
III. Key Agreement for Key Graphs We have constructed more efficient key exchange schemes which provides pairwise key exchange between parties via randomness re-use technique.
Sequential Key Exchange between Parties P1 P4P3 P2
Concurrent Key Exchange between Parties P1 P4P3 P2
Motivation How do we efficiently do concurrent execution of the two-party key exchange scheme ?
Our Results An efficient one-round key exchange scheme providing key independence in the standard model A two-round key exchange scheme providing forward secrecy in the standard model