How do We Make Encryption More Accessible?

This post is about a program I wrote to publish public keys in gravatar images. You can try it (if you’ve got a gravatar account) here or look at the source here.

HELO
250 Hello, I am glad to meet you
MAIL FROM:˂professor.bob@staff.uni.edu˃

When I was at university, discovering that I could easily have a conversation with the computer that managed mail was great fun. There were rules for our conversation of course, but they all seemed very civilized; I had to start by saying HELO, and it would give me some equally polite response. After that though, it quickly became obvious that it was a little too trusting. If I said that I was giving it mail from the.president@theWhitehouse.gov, or some lecturer or even some cute girl that my friend liked and that the mail was for my friend, it would just say Ok, Bye and then go ahead and deliver it.

It doesn’t take a genius to see that there’s quite a lot of potential for mischief there. Things have moved on a little since then, but probably less than you think. Email for most people is still not much more advanced than passing crumpled notes around a classroom. It has many of the same features – anyone on the path from the originator to the recipient can read it, the originator can pretend they never sent it if it turns out that their affection is not reciprocated, or worse, it’s easy for someone to forge one and create all kinds of opportunity for comedy. I suppose the main difference is that instead of it being a classroom, we’re talking about the world, and instead of it being about whether Emma likes Richard or not (she did), it’s about every aspect of our lives, including money, job, family, etc.

PRISM logo

This has been in peoples minds recently with news that various governments are logging every word, not just of email, but of everything we do online. This of course opens up even more potential for mischief. Normal individuals have already used the no fly list as a way of punishing people they didn’t like, but given the NSA and others, a few well placed forged emails might be easier than the phone calls and less risky.

Anyway, I’ve got some great news. A bunch of guys have been working on this, and they’ve come up with a really clever system that makes it basically impossible for anyone you didn’t intend to look your messages to read them. I was telling my Dad about it recently, and he found it hard to believe, but it’s just a bunch of maths, not even as complicated as you might expect and it more or less completely solves this problem.

There is of course a catch. The catch is that this scheme was invented independently at least twice in the 1970s, predates the use of the word ‘internet’ yet for some reason normal people are still using systems that are much less deserving of trust than they appear.

One of the problems is that of ‘key management’. You usually use a pair of computer ‘keys’ to enable this kind of security and you need a way to make one as available as possible, and the other as secret as possible. This is not really within the realm of possibility for normal humans, who regularly lose their physical keys or ‘hide’ them in obvious places despite the fact that they secure a majority of their worldly possessions. That’s a simple metal token that can easily be carried everywhere with you and is always around when you need it, and can’t be copied quickly without you noticing (generally speaking). The computer keys are harder to change if stolen, and easier to lose. Basically I shouldn’t be trusted with anything as precious as my own private key.

The next problem is that so few people are currently using any better system that it becomes difficult to find people to communicate with. This is probably partially because of the third problem:

The third problem is probably just software. There is no software that doesn’t make sending and receiving encrypted messages a massive pain. On top of that it’s hard (but not impossible) to enable important features like search on encrypted data.

I came up with a few ideas of my own to try to make this more reasonable. I wanted to use images with public keys embedded into them, so that when you see the image of someone in your address book, you also have the means to send them private messages, and possibly little seal images that are your private key, so you drag them onto data to sign the data. I think a much more visual, drag and drop system stands a much better chance of getting people using it. I also wanted to build on top of services that people already know about. Bitcoin is an encryption based currency system that lots of people are interested in, and Gravatar provides a sort of directory of email addresses to images.

The perfect system that I imagine is something that is easy enough to use for people who aren’t very technical, builds on top of things like Bitcoin and Gravatar, and probably provides a mail service that can’t read your stored history of emails but allows you to search them quickly and automatically encrypts messages to people or alternatively sends them a link that enables them to retreive the message over https. I didn’t create that, but I have created a proof of concept to show that some of these ideas are pretty doable. It’s still very rough and ready, so it’s not something for the non technical yet, but I think it shows one approach we could try using to bring private communications to everyone. You can try it (if you’ve got a gravatar account) here or look at the source here.

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