Re: [TLS] TLS 1.3 Recommended ECC curve for 192-bit security

The statement i [1] is about AES, and is very true. AES-192 is very seldom
used, and people tend to jump directly to AES-256.

For ECC curves, the opposite is true, people tend to use P-384 instead of
P-521. Most likely because of that P-384 is used in suite B. According to
[2], Google Chrome recently dropped support of P-521.

[2] 
https://support.globalsign.com/customer/portal/articles/1995283-ecc-compati
bility

The security level of the AES_256_GCM_SHA384-algorithms is clearly no more
than 192 as SHA-384 is used.

On 12/10/15 15:18, "Sean Turner" <sean@sn3rd.com> wrote:

>It is interesting to note that in discussing update IPSec’s RFC 4307
>somebody suggested making 192 a MAY because folks only use 128/256 [1].
>
>spt
>
>[1] http://mailarchive.ietf.org/arch/msg/ipsec/1F5h4j-dP5dLPCCAqg4iqgjjYFE
>
>On Oct 12, 2015, at 05:01, John Mattsson <john.mattsson@ericsson.com>
>wrote:
>
>> I think the selection of MTI Cipher Suites (Section 8.1 of
>>draft-ietf-tls-tls13-09) is excellent, but I am missing a recommended
>>ECC curve for the “SHOULD” cipher suites. Little benefit of using
>>AES-256 with P-256 or curve25519. Shouldn’t there be a SHOULD implement
>>ECC curve giving at least 192-bit security? E.g.
>> 
>> "These cipher suites SHOULD support both digital signatures and key
>>exchange with secp384r1 (NIST P-384)."
>> 
>> Cheers,
>> John
>>  
>> <13DEFB94-F735-49B0-8196-BDB5C9017A32[3].png>
>> 
>> JOHN MATTSSON
>> MSc Engineering Physics, MSc Business Administration and Economics
>> Ericsson IETF Security Coordinator
>> Senior Researcher, Security
>> 
>> Ericsson AB
>> Ericsson Research
>> Färögatan 6
>> SE-164 80 Stockholm, Sweden
>> Phone +46 10 71 43 501
>> SMS/MMS +46 76 11 53 501
>> john.mattsson@ericsson.com
>> www.ericsson.com
>> 
>> 
>> <D377E800-0A1A-43D3-AF5E-165F697789B5[3].png>
>>  
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>