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Improved CCMP PN Usage. Mark Matson mmatson@broadcom.com David Johnston david.johnston@ieee.org. Problem. CCMP Packet Number Ordering Is Inconsistent: Broadcast order changed to LS (octet 0) first MIC and CTR usage remained MS first Early specs didn’t show byte reversal
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Improved CCMP PN Usage Mark Matson mmatson@broadcom.com David Johnston david.johnston@ieee.org Mark Matson, Broadcom; David Johnston, Mobilian.
Problem • CCMP Packet Number Ordering Is Inconsistent: • Broadcast order changed to LS (octet 0) first • MIC and CTR usage remained MS first • Early specs didn’t show byte reversal • During reception, hardware implementation must buffer and reverse this one field only • Increased complexity Mark Matson, Broadcom; David Johnston, Mobilian.
Solution • Insert PN into MIC_IV and CTR_PRELOAD in the same order it’s broadcast (octet 0 first) • Maintains security • Satisfies NIST CCM nonce requirements • PN field remains unique for each packet • PN still available to facilitate replay detection Mark Matson, Broadcom; David Johnston, Mobilian.
Packet Number Is Broadcast and Received As PN0-5 Mark Matson, Broadcom; David Johnston, Mobilian.
Use in CTR_PRELOAD in Same Order Mark Matson, Broadcom; David Johnston, Mobilian.
Use in MIC_IV in Same Order Mark Matson, Broadcom; David Johnston, Mobilian.
The Text • Document 12-02-xxxr0 contains text and instructions to the editor for making changes to section 8.3.4 and its subsections. • Changes are with respect to D3.0 of TGi spec. Mark Matson, Broadcom; David Johnston, Mobilian.
Motion • Instruct the editor to incorporate into the draft the changes described in document 11-02-xxxr1 Mark Matson, Broadcom; David Johnston, Mobilian.