In my world, there are a race of mystical elves called iSophIans or as they called themselves Philosopherios, Keepers of the Road. They are a dual faction race of secretists. Few who aren't born into it have attained camaraderie by discovering their elusive trail of encoded messages throughout a network of readily available information. How would one contact them or learn how to decode there crumbs?
One pattern can be found in countless books and movies: The path is intuitive to one who has reached enlightenment.
Assume that the secret society publishes part of their teachings. Could be a blog on spiritual living, a book long out of print that is available in dusty bookstores, or the personal guidance of a guru in a remote temple. These teachings are the introduction to a coherent worldview. Anybody who has mastered those teachings will find similar patterns in other parts of the world.
- Hey, the sign of that cafe looks exactly like the carving of the hidden temple. Let's go there, order a herbal tea, and say ommmm. See if the barkeeper recognizes me as a brother in faith and gives me a cryptic koan for the next step.
- This mountain glade looks exactly like the one described in The Secret of Enlightenment, chapters 42 to 84. So this is the path to worldly success, and that is the path to eternal bliss. Let's hike that way.
- When in doubt, take the more rugged path, the upward path, or the left path if nothing else helps to make the call. But if there is a rugged, left, upward path, taking that one would be presumptious (i.e. the wrong choice) unless you are almost to the destination.
- The teaching suggests e.g. to meditate at the shore of mountain lakes, and many mountain lakes have villages of your elves nearby.
Compare with the fictional conspiracy theorists who look for the pentagram in a city map or building plan and overlay it with the symbols on a banknote, divided by the square root of the height of the cathedral, or with the real nutcases who do the same.
As usual it depends on a lot of different factors, so I will make some assumptions to keep it simple:
- The iSophIans don’t change the code
- The iSophIans code is relatively simple
- The iSophlans coded messages are regularly accessible
- The iSophIans and the outsiders use the same alphabet and language
- The iSophIans use coded communications to relay messages about what is going on in the world around them
One option would be to gather as many coded messages as possible and then count the frequency of occurrence of each letter in the collection. Next count the frequency of occurrence of letters in a lot of plain text. Now compare the frequencies to find out which letter is which. The most common letter used in the code is the same as the most common letter used in plain text which in fact is “e”. Repeat for the second most frequent and third most frequent until you have identified all of the letters.
You would be lucky to get all of the letters, but you should be able to get a lot of them if you had a sufficiently large sample of text to work on. After that the same process might be repeated with words for example t*e is used a lot – well * is probably “h”.
Another technique that could be used would be to trick them. If you suspect you know their place name for a location but want to confirm it, you can arrange for something odd to happen there. Something that you know they would be bound to notice and report. Perhaps a carnival in a remote location or someone dressed up in strange clothing or someone waving an enormous flag. Wait for the coded message and see if it matches your expectations.
There are many other methods that could be used. There are also ways of dealing with all of the simplifying factors I have introduced but things become more complex.
Ive seen a similar story subject through various movies and TV shows that was very intriguing. Basically its:
Subtle Iconography interpreted through Religious understanding
In the show I saw, they claimed gypsies would mark various areas with subtle symbols like a moon or sword or glyph. The meaning of these symbols would only be known to other gypsies who had the same mythical tradition. Like the door marked with the moon is a trap because the moon represents death while the door marked with a leaf is the way out as it represents life.
This is indeed a practice used by secret orders like the masons with their own symbolism and ancient civilizations like the Egyptians.
But what is important for you to consider is, the more graphic the symbol is (as in a recognizable shape like a leaf or sword) the easier it is for unaware people to ignore it as senseless graffiti. The meaning of the symbol can be virtually anything related to the cultures mythology. A sword could represent safety because there is a prolific story of some swordsman saving a town from some disaster, whereas everyone else would think oh sword means "danger or violence, stay away".
I like the idea that these mystical elves are very full of themselves and their secrets, but are actually not all that smart and are very unsophisticated with essentially no interactions with societies outside their own. Their code is a letter substitution cipher (each letter substitutes for a letter 3 letters down). This is immediately obvious to the person who is interested in reading the secret annals of their order.
When the iSophlan elves realize that someone is able to read their code, they indignantly make a new code much harder to break: each letter is substituted first for a letter 3 letters down, then 4 letters up, then 5 letters down, then 6 letters up, then 7 letters down, then 8 letters up. They are certain that so many substitutions will be enough to throw any would-be sleuth off the trail!
On the interwebs somewhere there is a secretive club who have distributed a series of increasingly difficult puzzles (true story, but I have forgotten their name or where I encountered a reference to them). The trick is that in order to join this mysterious club, one has to first find the first puzzle, solve it in order to find a reference of some sort to the next puzzle and so on until you find the final one. Solving the final puzzle is your entry to the club. Is this the kind of thing you have in mind, @IwishIcarus?
Using a real-world analogy, your elves might start by posting personal ads containing clues to the first puzzle, which might then be found in a comic strip in the Sunday paper. One would have to backtrack to older copies of the paper to find the entire puzzle. Solving the comic strip puzzle might lead you to a readily available book on horse-breeding, which turn would lead to JRR Tolkien's elfish script, and so on.
In a more medieval setting, where writing is less prevalent, the first clue might be a popular folk song performed by travelling minstrels everywhere. This might then a seeker to the local clergyman who would have a little-known parable of some kind, which then leads to a map (multiple copies available, but slightly hard to come by) with mystic symbols encoded in the scrolling around the edge of the map, which might point out location, which if our protagonist were to travel there, would start them on a trail of signs (signs on inns, road signs, carved lintels and other "random" signs), which would then ultimately lead to the front door of the elves' hold.