[HN Gopher] Letterlocking
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Letterlocking
Author : krisbolton
Score : 137 points
Date : 2021-03-23 14:06 UTC (8 hours ago)
(HTM) web link (en.wikipedia.org)
(TXT) w3m dump (en.wikipedia.org)
| prionassembly wrote:
| Something like this is mentioned in the _Hagakure_ , but I didn't
| understand what it was for until now.
| akeck wrote:
| There's a sub-culture of origami related to this called "Envelope
| and Letter Folding".
| anorakoverflow wrote:
| Looking at the links in the Wikipedia article I discovered this
| wonderfully "old web"-style page with various envelope folding
| guides[1]. I found it so endearing that I sat down and tried a
| few of them out, which was great fun.
|
| [1] http://www.orihouse.com/elfa.html
| [deleted]
| SamBam wrote:
| In the example image, it seems sealing wax is required to
| authenticate that the lock has not been opened.
|
| If sealing wax is going to be used anyway, why not just fold the
| letter and seal with wax like normal?
| function_seven wrote:
| With just a flat wax seal, is it possible to lift it off one
| surface, read the letter, then with a little extra wax, reseal
| the letter?
|
| If there are other pieces of paper held in the wax like a 3D
| matrix of sorts, it gets much more difficult to undo then redo
| the seal.
| hinkley wrote:
| If you can color match, probably.
|
| Rumor has it that Cardinal Richelieu's men had ways to read
| wax sealed documents.
|
| How many of these documents have multiple layers of meaning
| embedded in them? Steganography, euphemisms, inside jokes,
| shibboleths, what have you. I wonder how many things these
| letters say that we simply cannot read.
| signaturefish wrote:
| It's pretty easy to non-destructively lift a wax seal off of
| paper, with a sharp, hot knife and a bit of practice. You can
| then read the letter and reseal it with a touch more hot wax or
| the back of a heated spoon (to melt the back of the original
| seal).
|
| Not that I've ever done that, as a courier, in a live-roleplay
| game, ever. Repeatedly ;D
|
| Depending on the security level of the letter, of course, a
| non-letterlocked letter might be pretty readable even if
| sealed. A simple letter where the seal authenticates the sender
| but doesn't protect the contents might simply be folded in
| three and sealed closed - you can bend and flex such a letter
| without breaking the seal to read most of it. A more important
| letter being _protected_ by a seal might be folded into an
| ersatz envelope and then sealed on the join ... but that's most
| of the way to a basic letterlock.
|
| So, like all communications there's a tradeoff between
| complexity and security, and whether you're using the seal
| merely to authenticate the sender (which was pretty common) or
| also to protect the contents.
| pavel_lishin wrote:
| > _Not that I 've ever done that, as a courier, in a live-
| roleplay game, ever. Repeatedly ;D_
|
| Well now I'd love to hear more about this!
| signaturefish wrote:
| To answer your question, the lifting technique I refer to
| works well on flat paper and variably well on non-flat paper.
| Something as delicate as a letterlock, I'd be seriously
| concerned about my hot knife nicking or tearing a part of the
| lock that I can't see under the seal ... and /that/ would be
| obvious.
|
| So it's not so much that the seal holds the lock closed, as
| that the seal obscures the lock to the point that opening
| non-destructively is much harder.
| Animats wrote:
| There was at one time a stapler-like device which did that
| automatically. It cut a slot and a tab, and pushed the tab
| through the slot.
| codazoda wrote:
| Apparently these are called a "paper clinch".
| cbcrenshaw wrote:
| I don't know much about the device you describe, but fastening
| papers with something like this is probably way better than
| staples if the goal is long-term storage. Staples and other
| metal fasteners are pretty destructive. The National Archives
| offers guidance for fastened document preservation, for
| example, here: https://www.archives.gov/preservation/holdings-
| maintenance/f.... Staples can add a lot of unneeded bulk to
| records, too.
| dhosek wrote:
| There still is. We have a couple of these in my house. It's not
| as effective as a metal stapler, but it works well enough for
| things that we don't need permanently connected (plus it's much
| safer for my 6-year-old kids to use).
| gen220 wrote:
| There was a cool article on this subject a few weeks ago:
| https://www.npr.org/2021/03/02/972607811/reading-a-letter-th...
|
| Basically, opening centuries-old letters that are sealed with
| this technique is usually a destructive process: you might end up
| rendering some portions of the letter unreadable.
|
| As such, many of these letters have never been opened! They might
| contain interesting things, but we have no idea.
|
| Some researchers figured out a way to "unfold" X-rays of these
| intricately-locked letters, to render the letter legible without
| having to actually open it! It's a pretty cool technique.
|
| The underlying paper is here:
| https://www.nature.com/articles/s41467-021-21326-w
| hinkley wrote:
| Some of the things we've done with old letters are fascinating.
|
| I remember when they figured out how to use spectral analysis
| to 'see' the solvents that soak into paper from the ink,
| allowing them to read words that had flaked off due to the ink
| or the paper delaminating, especially at the edges of paper.
| msp-m wrote:
| this is one of those technologies - drop a letter from
| centuries ago onto an x-ray and let it get displayed on a
| computer screen - that will really make future tech look like
| "magic"
| jedimastert wrote:
| That articles leads me to one of my kinds of YouTube channels,
| and my favor type of little corner of the internet: A vast
| array of oddly specific and niche knowledge I had no idea I
| wanted
|
| https://www.youtube.com/channel/UCNPZ-f_IWDLz2S1hO027hRQ
| morsch wrote:
| Great style. Very old school. A candidate for
| (unintentional?) ASMR.
|
| It seems almost impossible to find these videos or channels
| intentionally, you can only stumble upon them.
| bb123 wrote:
| Ah yes the original version of "warranty void if opened".
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