Subject: [perpass] Metrics and Work Factor

From: Phillip Hallam-Baker <[email-masked]>
Date: Mon, 28 Oct 2013 22:43:42 -0400

I am at a workshop on Cyber Metrics at MIT.

When we are talking about protection against targeted surveillance then we
look for the cost of a single attack to be prohibitive and we accept a
certain set of costs to the user.

But for stopping pervasive surveillance we can't always bear those costs.
Significantly increasing the per message work factor is still a benefit
even if the work factor is not prohibitive for single messages.

-- 
Website: http://hallambaker.com/

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From: Yoav Nir <[email-masked]>
Date: Tue, 29 Oct 2013 06:42:49 +0000

On Oct 29, 2013, at 4:43 AM, Phillip Hallam-Baker <[email-masked]>
 wrote:

> When we are talking about protection against targeted surveillance then we look for the cost of a single attack to be prohibitive and we accept a certain set of costs to the user.
> 
> But for stopping pervasive surveillance we can't always bear those costs. Significantly increasing the per message work factor is still a benefit even if the work factor is not prohibitive for single messages. 

Absolutely. If we can get the cost of surveillance to be such that the NSA can only afford to spy on 10,000 people, it's likely that most of us will not be under surveillance. I believe that I don't rank anywhere on the list of 10,000 most dangerous terrorists or criminals. That doesn't necessarily have to be measured in bits. If reading my email required breaking into my home and stealing the private key off of my computer, that would severely limit the scale.

If we can ever get there, we've made significant progress in terms of privacy. That would still leave the issue of activists and whistleblowers treated as terrorists (or more correctly, wasting tax-payer money to fight political opponents), but it would still be progress

Yoav

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From: Phillip Hallam-Baker <[email-masked]>
Date: Tue, 29 Oct 2013 23:16:03 -0400

On Tue, Oct 29, 2013 at 2:42 AM, Yoav Nir <[email-masked]> wrote:

> > When we are talking about protection against targeted surveillance then
> we look for the cost of a single attack to be prohibitive and we accept a
> > But for stopping pervasive surveillance we can't always bear those
> costs. Significantly increasing the per message work factor is still a
> benefit even if the work factor is not prohibitive for single messages.
>
> Absolutely. If we can get the cost of surveillance to be such that the NSA
> can only afford to spy on 10,000 people, it's likely that most of us will
> not be under surveillance. I believe that I don't rank anywhere on the list
> of 10,000 most dangerous terrorists or criminals.

Security researchers will always be targets because people tell us about
exploits. I avoid any contact with dissident groups precisely because there
is a risk that I am being watched for other reasons.

> That doesn't necessarily have to be measured in bits. If reading my email
> required breaking into my home and stealing the private key off of my
> computer, that would severely limit the scale.
>

Please don't limit the threat model to the NSA. Yes they have goofed and
they understand that. And every public and private piece of information I
have on the matter points to a massive editing session taking place on the
senior ranks of the entire intel apparatus of the US right now.

But the new threat model includes all the governments aspiring to copy the
Snowden era NSA.

And pretty soon quite a few governments besides the US govt. are going to
realize that they are now in a decidedly negative sum game.

Cryptography is not about defending secrets, it is about enabling. Think of
all the Internet commerce happening today because of cryptography. That is
what, a trillion dollars of global activity a year?

So far we have only secured the Web to create the Internet equivalent of
shops. We still don't have secure mail to compliment that.

I don't know how much economic value we can generate with the next
generation of Internet crypto but I will bet it is in the tens or the
hundreds of billions.