Apparently this topic's in the air, what with the release of the Imitation Game this month.

That film's about Alan Turing and cryptanalysis of those German Enigma machines during WWII.

I said cryptanalysis and not cryptography, a word you may know better,

because cryptography is about sending a message securely by changing it, often changing it so it looks meaningless.

This is obviously useful when there's a way for the receiver to change it back and see the original message.

Cryptanalysis, on the other hand, works out ways to understand and break those systems,

to understand how the message is being changed by this system

so that you, unintended recipient with your prying eyes, can read the original message.

But this is all my brother's field. I should grab him and you two can talk about it sometime.

It's all separate from decipherment, which is an attempt to recover messages in an unknown writing system.

Cryptanalysis works with texts that were meant to elude you.

Decipherment works with messages that were once plainly readable,

but aren't any more thanks to accidents of history.

So, as you'll see in next Friday's video, which contains both, hidden codes often use characters we recognize to hide a secret message,

undeciphered scripts have characters we can't even read or identify

that stand between us and a not-so-secret, or not intentionally secret, message.

Of course, there is that pesky Voynich manuscript, which may be both!

With all this in mind, you've got a bit of background to appreciate next week's video.

I'd like to take the time to welcome all new subscribers, you're making it so much fun to talk about language here.

Big smiles for all of you! And let me know in the comments if you're interested in continuing this topic

with a short series that looks deeper at the decipherment of writing systems like Egyptian and Mayan.