Maybe It's Snake Oil All the Way Down

Bill Stewart bill.stewart at pobox.com
Tue Jun 3 18:01:51 EDT 2003


At 11:38 AM 06/03/2003 -0400, Ian Grigg wrote:
>I (arbitratrily) define the marketplace for SSL as browsing.
...
>There, we can show statistics that indicate that SSL
>has penetrated to something slightly less than 1% of servers.

For transmitting credit card numbers on web forms,
I'd be surprised if there were 1% of the servers that *don't* use SSL/TLS.

Virtually all deployed browsers support SSL, except a few
special-purpose versions.  The web servers supporting
almost all of the web support SSL if they have keys installed.
While many of them haven't bothered paying money for certified keys
or doing self-signed keys, I'd be surprised if it's really
as low as 1%.  What's your source for that figure?

While only a small fraction of web pages, and a much smaller
fraction of web bits transmitted, use SSL, that's appropriate,
because most web pages are material the publisher wants the public to see,
so eavesdropping isn't particularly part of the threat model,
and even integrity protection is seldom a realistic worry.
(By contrast, eavesdropping protection and integrity protection
are critical to telnet-like applications, so SSH is a big win.)

It's nice to have routine web traffic encrypted,
so that non-routine traffic doesn't stand out,
and so that traffic analysis is much harder,
but there is a significant CPU hit from the public-key phase,
which affects the number of pages per hour that can be served.
Corporate intranet web traffic carried across the public internet
sometimes uses SSL, but usually uses IPSEC because that also supports email.



In addition to web browsing and email submission,
there's an emerging market for SSL-based VPNs appliances.
Neoteris is one of the pioneers, and Aventail and some others are players.
The intention is that you can get "clientless" (browser-based)
support for intranet web browsing and email,
and lightweight client support for telnet,
while only having to buy an overpriced server box.
(And the box doesn't even need crypto accelerator help,
because the public-key phase only gets used for login,
while most sessions are long enough that this amortizes quickly.)


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