Historical Communications Security
“Check your flaps and seals.”
If you’re a spy history buff, like I am, you’ll recognize that as an admonition to a fellow practitioner to make sure that their communication is secure and that they don’t have any “leaks” in their organization. When I was in high school, back before essentially all communication that mattered was digital, “tradecraft”, as it related to the spy game, was all about surreptitiously opening someone else’s mail, reading it, and then sending it along, possibly altered. The first codes go back to at least the time of Caesar and have been in use for centuries. In modern secure communications, we are often concerned with verifying that the sender of information is, in fact, the party who claims to have sent it and that it hasn’t been tampered with. In digital communications, both tampering and providing algorithmic checks to discover tampering are surprisingly easy to implement and use. Of course, most people don’t bother because, well, most of us don’t have to worry much about secure communications.
But, somewhere between the two extremes of ancient cyphers and modern digital encryption and verifications, between the 10th and 17th centuries, innovative letter-writers developed other ways to let their recipient know that the letter is from whom it claims to be and hasn’t been tampered with called letterlocking. I’d never heard of this, until I read Before Envelopes, People Protected Messages With Letterlocking. Now, I figure most of my readers will be familiar with things like wax seals and signet stamps to “secure” letters, but, like me, had never heard of “letterlocking”. It’s fascinating, the idea of folding and stamping and marking letters, mostly without envelopes, to try to ensure message security. It reminds me of my primitive note-passing in grade school. If I’d had access to the letterlocking dictionary, things might have been more interesting.
So, as I warned you earlier this year, I’d still post things on Friday, but I completely expect that they’ll be increasingly idiosyncratic and may not be “fun” or interesting to anyone else but me. But, also, I encourage you to write a physical letter and use the letterlocking dictionary to teach yourself one of the letterlocking methods there, just for fun. I may just start leaving love notes for my wife this way. Then again, I may not. Maybe if she reads this and mentions it to me, I will. Think of it as yet another method of verifying communication. (Also, don’t worry. My blushing bride has a pretty damn good sense of humor. She needs to be married to me!)
Come back next week to see what I come up with next!
This post originally appeared on Use Your Words!
