Thursday, March 13, 2014

Transport layer security on the Internet

Yesterday I posted this:

and sent the link off to some friends and family. They had some good things to say, and some of that helped me clean it up a bit. But the feedback and discussions I had also helped me to step back a bit from the specifics of that proposal and think more generally about the problem.

The problem I'm talking about is a mash-up of technical detail, privacy concerns, security concerns and good old fashioned apocalypse with a dash of conspiracy anti-government kind of stuff. So there's definitely more than one way to look at it. I like to think of it as "collapse of trust on the Internet as we know it".

Here's the scenario: at some point in the next 5 years, a method is discovered that allows people with enough computer power to decrypt 'secure' https connections. Once this is generally known to the public (e.g. via a leak like that of Mr. Snowden), no one will 'trust' that any communications on the Internet is safe. Banks and credit cards companies will stop accepting any transactions from the Internet, and e-commerce will collapse. How that will impact the world, I'll leave to your imagination, but I don't think it will be pretty.

The anti-establishment rogue in me gets some satisfaction from that scenario, but I also know that in a crisis, it's the people at the bottom of the ladder that get crushed, and mass human suffering isn't something I'd like to encourage.

So here are some follow-up notes to my post:

What problem are we trying to solve?

Avoiding a disaster is a nice big picture goal, but not one that lends itself to a specific solution. One way of framing the problem is narrowly, which is what I suggested in my post - i.e. focus on the mathematics behind the encryption problem.

On the other hand, perhaps that's not the right problem to solve? It's not a new problem, and it's been around for about 20 years and there hasn't been a whole lot of progress or change.

The mathematical piece of the problem as it is currently framed is about how to provide a "Public Key Infrastructure" (PKI) using mathematics. A PKI is a way of solving the more abstract problem of 'how do you establish trust between two parties on the Internet', where the only communication between them is this stream of bytes that appear to be coming from a source that is reliably identifiable only as number? What if that doesn't have a reliable solution?

The short version of what suddenly got quite complicated is this: this part of internet security was designed for e-commerce, in a bit of a hurry, back in the early days of the Internet when machines were less powerful and e-commerce was a dream. Then the dream actually came true (after the Internet bubble and collapse) but those emperor's clothes are pretty skimpy.

So "who do you trust and why" is the bigger, more abstract problem, and treads on some scary ground. Is there a different solvable technical problem somewhere in here, bigger than the mathematical problem of a PKI but smaller than the completely abstract one?

What problems are already solved?

My smarter older brother pointed me to these:


A smaller more tractable problem is 'symmetric encryption' (which isn't a mathematical solution to a PKI on it's own), and this solution has been adopted as a new standard. In other words, if you have a prior relationship with someone and way of sharing secrets outside of the Internet, then a secure private channel is not all that difficult.


This appears to be a solution to negotiating a shared random secret key, which solves part of the PKI problem (it helps provide a secure channel with your correspondent, it doesn't help prove who they are).

c. Human nature

Yeah, just kidding. Just to be clear though - none of this solves the general problems of fraud and how humans have built a glorious, terrible thing built on machines and social interaction, and how fragile it is. Perhaps that part of the problem (who do you trust) is not going to have a technical solution.