Subject: [Hipsec] Reference problem in 5201-bis wrt SECP160R1

From: Robert Moskowitz <[email-masked]>
Date: Wed, 08 Aug 2012 09:24:22 -0400

For low security we have SECP160R1 from:

    [SECG]                      SECG, "Recommended Elliptic Curve Domain
                                Parameters", SEC 2 , 2000,
                                <http://www.secg.org/>.

I went there yesterday to look up some of the information on actual 
sizes and got to:

http://www.secg.org/download/aid-784/sec2-v2.pdf, published Jan 27, 2010.

And no SECP160R1, the smallest keysize now is SECP192R1 (sec 2.2.2).

So we have a reference problem here as well as giving a developer the 
parameter values needed to implement SECP160R1.

Corrective action options:

1) Directly supply the parameters for SECP160R1 in Appendix D and 
reference the version of secg they were pulled from.

2) Find a more stable source for SECP160R1 to reference.

3) Move to SECP192R1 (which I am leary of as ver 3.0 of secg could drop 
that!).

I vote for 1) and ask whoever has the older version of secg to forward 
the parameters for inclusion.

BTW, HIP DEX works a bit differently in that the keys generated from the 
ECDH exchange are only used in protecting HIP packets and a wrapped key 
exchange within HIP provides the keying material for session keys (eg 
ESP or 802.15.4 security).  So in DEX, using SECP160R1 may not be as 
much of a risk as in BEX, so I DO plan on providing the SECP160R1 
parameters in DEX.

---

From: Rene Struik <[email-masked]>
Date: Wed, 08 Aug 2012 14:35:14 -0400

Hi Bob:

You are correct that SECG removed the prime curve secp160r1 from the
SEC1 specification, when moving from v1.0 to v2.0. However, you can
still access this under the "superseded specifications" tab: the weblink
should be http://www.secg.org/download/aid-386/sec2_final.pdf.

You may also find this curve specified elsewhere, e.g., (if memory
serves me well) with some copy protection schemes, such as DTCP.

I hope this helps.

Best regards,

Rene

On 08/08/2012 9:24 AM, Robert Moskowitz wrote:
> 3) Move to SECP192R1 (which I am leary of as ver 3.0 of secg could
> drop that!).
>
> BTW, HIP DEX works a bit differently in that the keys generated from
> the ECDH exchange are only used in protecting HIP packets and a
> wrapped key exchange within HIP provides the keying material for
> session keys (eg ESP or 802.15.4 security).  So in DEX, using
> SECP160R1 may not be as much of a risk as in BEX, so I DO plan on
> providing the SECP160R1 parameters in DEX.
>
>
> _______________________________________________
> Hipsec mailing list
> [email-masked]
> https://www.ietf.org/mailman/listinfo/hipsec

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