Re: SC-based link encryption

2007-01-05 Thread Paul Hoffman

At 7:58 PM -0800 1/3/07, Steve Schear wrote:
I haven't been following the smartcard scene for a while.  I'm 
looking to create a low-cost and portable link encryptor, with D-H 
or similar key exchange, for lower 100kbps data speeds. Is this 
possible?


You could take an IPsec stack and repurpose it down one layer in the 
stack. At least that way you'll know the security properties of what 
you create.


--Paul Hoffman, Director
--VPN Consortium

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Re: SC-based link encryption

2007-01-05 Thread John Denker
On 01/05/2007 10:53 AM, Paul Hoffman wrote:

 You could take an IPsec stack and repurpose it down one layer in the
 stack. At least that way you'll know the security properties of what you
 create.

That is a Good Idea that can be used in a wide range of
situations.  Here is some additional detail:

This can be understood as follows:  Half of IPsec tunnel
mode can be described as IPIP encapsulation layered on
top of transport mode which does the encryption and
arranges for transport of the encrypted packets.

   The other half of IPsec is the SPDB, which is an
   important part of IPsec but is often underappreciated
   by non-experts.

So ... one obvious way forward is to do what might be
called L2sec (layer 2 security) in analogy to IPsec.
That is, do layer-2-in-IP encapsulation using GRE or
the like, and then layer that on top of IPsec transport
mode.

  Then you make some straightforward tweaks to the
  SPDB and you've something pretty nice.  As PH
  said, the security properties will be well known.

This may sound like overkill, but it is likely to be
/easier/ than anything else you can think of (not to
mention more secure and more richly featured).

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SC-based link encryption

2007-01-04 Thread Steve Schear
I haven't been following the smartcard scene for a while.  I'm looking to 
create a low-cost and portable link encryptor, with D-H or similar key 
exchange, for lower 100kbps data speeds. Is this possible?


Steve

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