Re: [perpass] SMTP and SRV records

[Eliot Lear <[e-mail]>]

Yeah, this is what I would suggest as well, especially for SMTP.  There
are a host of operational problems with attempting to vary the port.

Eliot


On 11/24/15 11:41 PM, Ted Hardie wrote:
> On Tue, Nov 24, 2015 at 2:23 PM, Ted Lemon <[e-mail]
> <mailto:[e-mail]>> wrote:
>
>     Tuesday, Nov 24, 2015 4:25 PM Eliot Lear wrote:
>     > What benefit would this add to the average user?
>
>     It's the germ of an interesting idea.   The theory would be that a
>     sniffer at the backbone would have to listen to all traffic, not
>     just traffic on port 25. 
>
>
> ​I don't think that's quite right.  A port-specific sniffer would have
> to know what SMTP port was correct for a specific domain.  Depending
> on the TTL of the record, that might turn into a table lookup for
> setting the sniffers rather than listening to all traffic.
>
> That said, I rather suspect that listening to all traffic is pretty
> much in the program of most signals intelligence agencies anyway,
> because the ephemeral ports can be be used by VoIP and other media
> traffic. DPI on that would tell you which ones were SMTP and which
> others pretty rapidly.
>
>      However, it's not as good as SMTP+TLS, and has the same adoption
>     problem, plus SMTP+TLS has a _big_ head start, so it's probably
>     better to concentrate our efforts on making that work even better.
>
>
> ​ Yes, focusing on getting encryption underneath it seems like a
> better use of energy; at most, port shifting is minor security through
> obscurity, and that doesn't tend to give you a lot of bang for your buck.
>
> Just my two cents,
>
> Ted ​
>
>  
>
>
>     --
>     Sent from Whiteout Mail - https://whiteout.io
>
>     My PGP key: https://keys.whiteout.io/[e-mail]
>     _______________________________________________
>     perpass mailing list
>     [e-mail] <mailto:[e-mail]>
>     https://www.ietf.org/mailman/listinfo/perpass
>
>