Re: [Hipsec] additional comments on latest RFC5201-bis draft

[Robert Moskowitz <[e-mail]>]

On 09/10/2013 03:56 AM, Miika Komu wrote:
> Hi,
>
> On 09/09/2013 07:50 AM, Henderson, Thomas R wrote:
>> Last week I published a new version of RFC5201-bis:
>> http://tools.ietf.org/html/draft-ietf-hip-rfc5201-bis-13
>>
>> This was mainly to address ID-nits and prepare the draft for the next 
>> stage of the review process. However, I also received a number of 
>> comments from Anders Brandt (cc'ed) on the version-12 draft. The 
>> purely editorial ones were included in version-13, but I decided to 
>> post a few for review on the list.
>>
>> In the interest of expediency, I'd like to suggest that we aim for 
>> resolving all of these within the next two weeks.
>>
>> 1) Section 4.1, the statement is made:
>>
>> "As a result, it is believed that the HIP opportunistic mode is at 
>> least as secure as current IP."
>>
>> Anders questioned what this statement means. Further clarifications 
>> are needed here.
>
> I would just suggest combining this sentence with the previous 
> paragraph. Alternatively, this could perhaps be rephrased as:
>
> As a result, opportunistic mode in HIP offers a "better than nothing" 
> security model. Initially, a base exchange authenticated in the 
> opportunistic mode involves a leap of faith subject man-in-the-middle 
> attacks, but subsequent datagrams related to the same HIP association 
> cannot be compromised by a new man-in-the-middle attack. Thus, it can 
> be stated that opportunistic mode in HIP is at least as secure as 
> unprotected IP-based communications.

+10000 :)

I really like this way of putting it. The MITM has one chance only and 
then must ALWAYS be in the middle. So maybe something else is needed 
that if the MITM "steps away", the attack is exposed after the fact?