(For the careful reader, please note, this presentation takes place some 10 years after the events chronicled in the Parasol Protectorate.)

July 30, 1883

Good evening Ladies & Gentlemen,

Aetherographic transmitters are growing in popularity in England and all other parts of the civilized world because they let us communicate instantly to anyone, anywhere, as long as there is aether to carry the message. If you take a dirigible flight above London you’ll see that many a House of Quality now boasts and aetherographic receiving chambers on the roof. The offices of the Bureau of Unnatural Registry have one of course, as do most of England’s Hives and Packs, as well as many well-bread daylight folk, Her Royal Highness included.

Undoubtedly, classified messages get transmitted on a daily basis and the only thing preventing eavesdroppers from learning everyone’s secrets are crystalline valves. In order to receive a message sent from one transmitter, you must have that transmitter’s crystalline valve in your receiving chamber at the time the message is sent. But the British Empire has many enemies. How long before one of them builds up dozens, hundreds, or even thousands of receiving chambers using every possible crystalline valve setting, recording secrets being sent from all corners of the world? All it would take is sufficient funds and a good deal of land. Has one of Britain’s enemies already built such an espionage network estate?

Since eavesdropping on aetherographic transmissions takes nothing more than petty resources, the only safe way to communicate through the aether is to assume that all of your enemies are listening. You can utilize fake identities and code-words to muddle the meanings of your messages, but fortunately there is a safer way to keep secrets: the fine art of encryption.

Encryption is nothing new. It is said that some of Egypt’s hieroglyphic writings are actually encrypted messages. Julius Ceasar, dictator of the Roman Empire, invented a cipher known today as the Ceasar Cipher, in which you shift every letter of your message a set number of characters later in the alphabet. With such a cipher, the word SECRET might look like FRPERG. Such ancient codes can be easily cracked now, during the Age of Science, but there are newer more secure codes in development.

And even before that, almost 80 years ago, Mr. Thomas Jefferson the noted American invented a device known as the Jefferson Wheel Cipher. It is a set of circular wheels on an axle, each wheel with the 26 letters of the Roman alphabet painted on its edge, the letters in shuffled order. Mr. Jefferson’s device had 36 such wheels. If two people pre-arranged which order the wheels were placed on the axle (this order is referred to as the key), then they can encrypt and decrypt messages together. One must spell out a message on any row by rotating the wheels, and then copy down any other row’s characters and deliver this message. The receiver of the message can copy these ciphertext letters on his own Jefferson Wheel Cipher, and as long as the key is the same, he can look at each row until he finds the plaintext.

How does this all relate to securing aetherographic transmissions from eavesdroppers? Let us invent characters to use as examples. Mrs. Chripshaw is in her London mansion, and Mr. Haverbink is in Paris on a top secret mission. Miss Duffletree is an American spy in Boston with a keen interest in what Mrs. Chripshaw and Mr. Haverbink are saying. For this example we can pretend that Miss Duffletree has successfully guessed or figured out which crystalline valves Mrs. Chripshaw and Mr. Haverbink are using to communicate. When Mrs. Chripshaw sends her secret message across the aether, Mr. Haverbink is sitting in a Parisian receiving chamber collecting each letter. But at the very same moment, Miss Duffletree is doing the same in Boston. Mrs. Chripshaw’s secret message fell into the greedy spying hands of Miss Duffletree.

However, now let’s pretend Mrs. Chripshaw and Mr. Haverbink both have a device similar to Mr. Jefferson’s Wheel Cipher. Before Mr. Haverbink leaves for Paris they both agree what key they will use to encrypt messages. Before sending the message, Mrs. Chripshaw encrypts it using her Wheel Cipher device. Then Mr. Haverbink and Miss Duffletree would both receive the same ciphertext at the same time. Mr. Haverbink, however, would be able to decrypt it with his Wheel Cipher, while Miss Duffletree would be stuck scratching her head.

Science has barely scratched the surface of encryption machines. In the end one will find that the strength of the encryption depends on the complexity of the key being used. In the case of the Ceasar Cipher, the key is simply a number between 1 and 25 – how many letters to offset each letter. This can be easily cracked by trying all 25 combinations until you see plaintext. In Mr. Poe’s substitution ciphers, the key is a scrambled version of the alphabet. It is much harder to crack than the Caesar Cipher because there are such an enormous number of possible ways to scramble the 26 letters of the alphabet. Not to mention there are clues in the ciphertext. For example, the letter E occurs much more often than the letter Z, so if you note a letter in the ciphertext that occurs the most often it is more likely an E than it is a Z. Given that, a simple substitution cipher can normally be cracked by a modern scientist within the space of one afternoon.

But, what if we use the power of technology to make the key so incredibly complex that it would take someone years or even centuries to try all combinations? What if you encrypted each letter of your plaintext using a different shuffled alphabet, the key being a series of dozens of shuffled alphabets? What if your key changed every day, and you could figure out what today’s key is supposed to be based on some sort of mathematical formula in relation to positions of the stars with a random, pre-shared variable in the mix? With the power of steam, in conjunction with the technology that makes Charles Babbage’s Difference Engine possible, we could devise a portable encryption device capable of scrambling messages that are virtually impossible for anyone without the proper key to de-scramble, and field agents could carry such devices with them.

Without encryption, our secrets are no longer safe! If we wish to use aetherographic transmitters to communicate, we must do so with full knowledge that our enemies will be watching every letter as it emerges from the aether! As aetherographic transmitters rise in popularity it becomes more and more clear that encryption, dear Sirs & Madams, is the future of long-distance communication.

Please join me in thanking him for this most marvelous presentation!

~ Miss Carriger

Book News:
Treehouse takes a look at the first three Parasol Protectorate Books.

Quote of the Day:
“In going upstairs the gentlemen should precede the lady; in going down, he should follow her.”
~ Etiquette for Gentlemen, 1850