eap Mailing List: Proposed Resolution to Issue 356: Ciphersuite Independence

[Bernard Aboba (bernard_aboba]

The text of Issue 356 is enclosed below.   The proposed resolution is to 
replace the first paragraph of Section 3.7 with the following:

3.7. Key Strength

As noted in Section 2.1, EAP lower layers determine TSKs in
different ways. Where EAP keying material is utilized in
the derivation, encryption or authentication of TSKs, it
is possible for EAP key generation to represent the weakest
link.

In order to ensure that EAP methods produce keying
material of an appropriate symmetric key strength,
it is RECOMMENDED that EAP methods utilizing public
key cryptography choose a public key that has a
cryptographic strength providing the required level
of attack resistance. This is typically provided by
configuring EAP methods, since there is
no coordination between the lower layer and EAP method
with respect to minimum required symmetric key strength."

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Issue 356: Ciphersuite Independence
Submitter name: Joe Salowey
Submitter email address: jsalowey [at] cisco.com
Date Submitted: April 30, 2006
Reference: http://lists.frascone.com/pipermail/eap/msg04223.html
Document: KEYING-12
Comment type: 'E'ditorial
Priority: '2' May fix
Section: 1.6.4
Rationale/Explanation of issue:

Section 3.7 implies that there is a system level coordination between
the strength of the keys exported by the EAP method and the strength of
keys required by the lower layer.

This section should reference this and indicate that the coordination is
done outside of EAP.