Ciphers, Codes, and Encryption
- Secret writings are always a function of literacy
- Woman sending encrypted letter to her lover
- Using substitution to figure out message
- Other questions guiding questions
- We don’t even need to know what the message says, only who is talking to whom
- ex. Mapping out allegiances of men, creating a network
- Networks made center around men
- Code: Variable sized elements that have meaing in the plaintext language, syllables, words, etc
- cypher: Transformation from plaintext
- Early uses: Fire to display wars being won
- Polybius square: Write alphabet out, using signal torches to symbolize different letters, first position = row, 2nd = column, 3rd = how far along
- Scytale: Spartans, stupid secret codes using strip of leather wound around rod, writing letters down length, unfurling + writing letters around to complicate
- Caesar shift:
- Worth remembering he was assasinated
- Using greek letters instead of Latin, shifting around
1000 years later, the fall of the Muslim conquest
- Accumulated Greek and Roman knowledge is translated into Islamic in Baghdad, one of the first unis/research centres
- Works out how to defeat Greek/Roman ciphers
- Counting number of letters/symbols, counting ranks, then figuring out statistical properties
- Most common letters, looking for frequencies
Meanwhile in Europe
- Not much cipher development
- Roger Baker, describes various secret writing systems, may have also encrypted secret of the Philosopher’s stone, using a grill (cardboard w holes cut out, reading letters that show thru)
- Otherwise, still quite behind
- Gutenberg press changing relationship with information
Francis Bacon
- Bi-lateral cypher
- 1623
- works out you can work out 24 letters of the English alphabet in A and B if you can do it in groups of five
- 32 distinct patterns
Nomenclators
- Mix of different cyphers and codebooks
- Mary Queen of Scots had one, was fine until gov. found her copy of it
- Lasting until beginning of 19th century
- Star chambers
- Groups dedicated to enciphering messages
- As history progresses, experimentation with secret codes continues
French Revolution
- Challenge for all countries with monarchies
- Systems needed to communicate & coordinate various armies
- New: Up on tallest building, take mechanized beam with a pivot point and movable arms on both sides
- Central beam can set at 4 angles, each arm can move at 7 angles
- 196 positions
- Each station had a code book
- System of one big general cypher
- MORSE CODE
Whirlwind tour
- Where are the gaps?
- Where are the women?
- Who/what is left out?
- What other things had to have happened to support all this?
- Remember Brecht poem
- Think critically, many different stories behind this one surface level progression
- Danger of a single story