Re: [Tcpcrypt] v3 of the charter

[Joe Touch <[e-mail]>]

On 4/30/2014 1:20 AM, Eggert, Lars wrote:
> Hi,
>
> a few comments. This is looking good overall.
>
> On 2014-4-30, at 8:35, marcelo bagnulo braun <[e-mail]> wrote:
>> TCP Increased Security (TCP Inc.)
>
> am not in love with the name, but don't want to start a bikeshed.
>
>> This is better than plain-text
>> because it thwarts passive eavesdropping, but is weaker than using
>> authenticated keys, because it is vulnerable to man-in-the-middle attacks.
>
> Is it desirable to have a model where you're vulnerable to MiM the
> first time you connect to a server, but not afterwards? (Like what SSH
> provides in terms of warning when the server key has changed?)

It might be, but this might require configuration coordination between 
hosts that share ID info - whether at a load-server or behind a NAT.

...
>> - must allow client to avoid fingerprinting: some clients may want to avoid appearing as the same
>>   client when connecting to a remote peer on subsequent occasions.  This should either
>>   be the default (clients cannot be "fingerprinted" by the server based on shared state)
>>   or some mechanism should be available for clients to drop or ignore shared state to avoid
>>   being fingerprintable any more than would be present for a cleartext session.
>
> Not sure if this achievable if you can already fingerprint clients based on existing IP and TCP header fields.

It already says "any more than would be present for a cleartext 
session". Sure, you get the info that TCP-Inc is supported, but 
shouldn't need to expose more about the client than that.

Joe