Group Key Management for PIM-SM Routers

1
Group Key Management for PIM-SM Routers

• J.W. Atwood, Salekul Islam
• Concordia University
• supplement to
• draft-ietf-pim-sm-linklocal-00

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Multicast groups formed by PIM routers

• PIM routers will form a large number of small SSM
  groups
• The number of SSM groups will be equal to the
  number of routers in the region
• In each SSM group, one router will be the
  speaker, and all the adjacent routers will be the
  listeners.

3
Join/Leave mechanisms

• No explicit join/leave
• Join deemed following
• New router added
• Router rebooted/power restored
• Leave deemed following
• Router crashes
• Router shut down/power fails

4
Forward/backward secrecy

• For user applications, PFS and PBS can be
  important
• For PIM-SM, legitimate routers are allowed to
  receive future messages
• This will reduce the work of the GCKS and
  simplify the required group key management

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Functions of GCKS

• Maintain membership information of all SSM groups
• Generate keys for each SSM group, and distribute
  keys to all pertinent routers
• Maintain key hygiene re-key as necessary
• Authenticate individual routers

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Functions 2

• When new router joins region, it is speaker for
  its group, and its neighbors are listeners. Need
  to send new key to (n1) routers.
• Refreshing the sequence numbers (for anti-replay)
  will be non-trivial
• Re-initialize SAs, or
• Inform new router of current sequence s

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Contact Information

• PPT/PDF of these slides are at www.cse.concordia
  .ca/bill/internet-drafts/IETF67-KeyManagement.pp
  t or IETF67-KeyManagement.pdf
• Email addresses
• bill_at_cse.concordia.ca
• salek_is_at_cse.concordia.ca