William Whyte, NTRU Cryptosystems

1
1609.2

• William Whyte, NTRU Cryptosystems
• October 15, 2008

2
1609.2-2006

• IEEE Std 1609.2-2006 contains secure message
  formats and certificate formats
• Some omissions anonymous certs
• Some bugs cert management messages need refining
• Incomplete set of services only really suited
  for apps that communicate by exchanging a small
  number of messages
• Integration with other 1609.x services is not
  clean
• Signed WSAs, secured WSMs have half the
  processing described in .2 and half described in
  .3
• No SAPs

3
1609.2 Revision 30,000 foot version

• Complete omissions
• Fix cert management bugs
• Expand set of services provided to include
  multiple security protocols
• At the very least, session-based protocols as
  well as message-based protocols
• Define classes of applications with different
  performance/security requirements
• Provide optimized security protocol for each
  class of applications
• Provide consistent way for applications to
  reference the security protocol they want to use

4
1609.2 Revision Structure

• Overview, Normative References, Definitions etc
• Presentation language
• Common formats and mechanisms
• Certs
• Scope checks and cert chain construction
• Security protocol 1 (eg secured messages)
• Message type definitions
• Message processing
• SAPs

• Security protocol 2 (eg secured WSAs)
• Message type definitions
• SAPs
• Certificate Management
• Requests
• Revocation
• Large revocation lists
• Annexes

5
Potential classes of application

• Types of message
• WSA
• Broadcast
• High-volume (eg Heartbeat)
• Moderate or infrequently changing (curve
  rollover)
• Perhaps less important to perform replay checking
• Transactional
• Secure session with local app (tolling /
  payment?)
• Secure session with server remote over backhaul,
  persistent across comm zones (download large
  amounts of navigation data)
• Type of identification
• Identified (broadcast)
• Identified (to specific endpoint, opt-in)
• Anonymous

6
Definition of SAPs

• Two different settings

App
Security Services
App
Network stack
Network stack
Security Services
7
How are mechanisms specified by their consumer?

• Application requests specific security service
  from security services or from network stack
• 1609.2 perhaps mandates that apps must use
  security
• Choice of security mechanism is made by app
• 1609.2 provides guidance as to how to specify that

8
Principles for adding mechanisms

• Avoid unnecessary multiplication of entities
• One protocol per application type
• Be reluctant to add additional crypto algorithms

9
Next steps

• WG consensus on this approach
• Develop and agree list of application classes
• Determine mechanisms (new or existing)
• See if there is a uniform SAP structure or if
  each mechanism requires specific SAPs
• Start on write-up