Friday, March 02, 2007

Very Hush Hush

Earlier today I had a need to e-mail someone a bunch of passwords. I'm not usually the paranoid type, but even I think that it can be a bit sketchy sending root passwords through e-mail. So, what's a guy to do?

Well, the obvious answer is encrypt them. But, the problem with most basic encryption schemes is you need to share with the other party the secret password to unlock the encrypted file. That kind of defeats the purpose, as you end up sending the password over e-mail, or IM, or through your wiretapped phone.

But, it turns out there's a much better way. That is, use public/private key encryption. This stuff is nothing short of magic of the coolest kind. Here's what you do: you send me your public key, which is totally public information. In fact, you want to publish your public key all over the place.

I then use your public key to encrypt a message for you. I then send you the message. Now, the only person on the planet who can decrypt that message is the you, using your private key.

Even myself, who created the encrypted message, can't decrypt it. It's a one-way kinda thing.

I'm sorry, but I just happen to think that's so cool that you can do that. It seems to defy all logic that you can use something completely public to make something totally private.

Anyway, it turns out that you can easily get the software to do this form of encryption. One well respected implementation of it is Gnu Privacy Guard.

GPG is industrial grade stuff, too. It's not unusual to have programs like Quicken that claim to encrypt files, yet you can buy a shareware program for $30 to "instantly recover lost or forgotten passwords." Sure, yeah, encrypted.

GPG also supports the idea of digitally signing documents. By signing a document you give people a way to verify not a single byte in the message has changed.

Check out this howto out to get started. You'll be feeling like a crypto-hacker in no time.

And here's my public key. Feel free to send me an encrypted message to make sure your setup works.

-----BEGIN PGP PUBLIC KEY BLOCK-----
Version: GnuPG v1.4.5 (Cygwin)
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=aVoF
-----END PGP PUBLIC KEY BLOCK-----

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