Course outline
Module 1
Module 1: Introduction to Zodiac Ciphers
Introduction to Zodiac Ciphers
Knowledge check
Q1. Who is the Zodiac Killer?
- A. A real person ✓
- B. A fictional character
- C. A group of people
- D. A symbol
Why: The Zodiac Killer was a real person who committed a series of murders in the late 1960s and early 1970s.
Q2. What is the main purpose of the Zodiac ciphers?
- A. To hide the killer's identity ✓
- B. To communicate with the police
- C. To solve the case
- D. To entertain the public
Why: The Zodiac ciphers were used by the killer to hide his identity and taunt the authorities.
Q3. How many ciphers did the Zodiac Killer send to the newspapers?
Why: The Zodiac Killer sent four ciphers to the newspapers over a period of time.
Q4. What is the name of the cipher that was fully solved?
- A. Zodiac Cipher 340
- B. Zodiac Cipher 408 ✓
- C. Zodiac Cipher 136
- D. Zodiac Cipher 320
Why: The Zodiac Cipher 408 was the first cipher that was fully solved by the authorities.
Q5. What is the main challenge in solving the Zodiac ciphers?
- A. They are too short
- B. They use simple language
- C. They use a complex substitution cipher ✓
- D. They are written in another language
Why: The main challenge in solving the Zodiac ciphers is that they use a complex substitution cipher, making them difficult to decode.
Module 2
Module 2: Historical Context of the Zodiac
Historical Context of the Zodiac
Knowledge check
Q1. Who was the first person to publicly claim responsibility for the Zodiac murders?
- A. Arthur Leigh Allen
- B. The Zodiac ✓
- C. Lawrence B. Fisher
- D. David Berkowitz
Why: The Zodiac was the name used by the killer to taunt the press and police, and he was the first to publicly claim responsibility for the murders.
Q2. In which year was the first Zodiac cipher sent to the San Francisco Chronicle?
- A. 1969 ✓
- B. 1970
- C. 1971
- D. 1972
Why: The first Zodiac cipher was sent to the San Francisco Chronicle in 1969, shortly after the first murders were committed.
Q3. What was the name of the Zodiac killer's symbol?
- A. The Eye
- B. The Cross
- C. The Zodiac Sign ✓
- D. The Skull
Why: The Zodiac killer used the symbol of the Zodiac sign, which was a circle with eight points, as his signature.
Q4. Which of the following was NOT a known victim of the Zodiac killer?
- A. Darlene Ferrin
- B. Michael Mageau
- C. Paul Stine
- D. John Lennon ✓
Why: John Lennon was not a victim of the Zodiac killer. He was a famous musician who was assassinated in 1980.
Q5. How many confirmed victims did the Zodiac killer have?
Why: The Zodiac killer is confirmed to have murdered four people, though he claimed to have killed many more in his letters.
Module 3
Module 3: Cipher Types Used by the Zodiac
Cipher Types Used by the Zodiac
Knowledge check
Q1. What type of cipher did the Zodiac use in the 408-character cipher?
- A. Caesar cipher
- B. Substitution cipher ✓
- C. Vigenère cipher
- D. Playfair cipher
Why: The 408-character cipher used a simple substitution cipher where each letter was replaced by another letter.
Q2. Which cipher is known for using a keyword to create a mixed alphabet?
- A. Caesar cipher
- B. Vigenère cipher ✓
- C. Playfair cipher
- D. Affine cipher
Why: The Vigenère cipher uses a keyword to create a mixed alphabet for encryption.
Q3. What is the main difference between a monoalphabetic and polyalphabetic cipher?
- A. Monoalphabetic uses one substitution alphabet, polyalphabetic uses multiple ✓
- B. Monoalphabetic uses numbers, polyalphabetic uses letters
- C. Monoalphabetic is harder to crack, polyalphabetic is easier
- D. Monoalphabetic is used by the Zodiac, polyalphabetic is not
Why: Monoalphabetic ciphers use a single substitution alphabet, while polyalphabetic ciphers use multiple substitution alphabets.
Q4. What cipher is used in the Zodiac's 340-character cipher?
- A. Caesar cipher
- B. Substitution cipher ✓
- C. Vigenère cipher
- D. Playfair cipher
Why: The 340-character cipher is also a substitution cipher, but it is more complex than the 408-character cipher.
Q5. Which cipher involves using a grid of letters for encryption?
- A. Caesar cipher
- B. Vigenère cipher
- C. Playfair cipher ✓
- D. Affine cipher
Why: The Playfair cipher uses a 5x5 grid of letters to encrypt pairs of letters.
Module 4
Module 4: Analyzing the 408-Character Cipher
Analyzing the 408-Character Cipher
Knowledge check
Q1. What is the length of the 408-character cipher?
- A. 340 characters
- B. 408 characters ✓
- C. 260 characters
- D. 500 characters
Why: The 408-character cipher is named for its exact length of 408 characters.
Q2. Which Zodiac killer cipher was the first to be solved?
- A. 340-character cipher
- B. 408-character cipher ✓
- C. 32-character cipher
- D. 13-character cipher
Why: The 408-character cipher was the first Zodiac killer cipher to be solved by cryptologists in 1971.
Q3. How many symbols are used in the 408-character cipher?
- A. 26 symbols
- B. 32 symbols ✓
- C. 40 symbols
- D. 52 symbols
Why: The 408-character cipher uses a modified version of the standard English alphabet with 32 symbols, including some special characters.
Q4. What was the main method used to solve the 408-character cipher?
- A. Brute force
- B. Frequency analysis
- C. Substitution cipher ✓
- D. Transposition cipher
Why: The 408-character cipher was solved using a substitution cipher technique, where each symbol corresponds to a letter of the alphabet.
Q5. Who was the first person to publicly solve the 408-character cipher?
- A. Lawrence Smith ✓
- B. Dennis Rader
- C. Elizebeth Friedman
- D. William Friedman
Why: Lawrence Smith was the first person to publicly solve the 408-character cipher, although he did not publish his solution until after the cipher had already been solved by others.
Module 5
Module 5: The 340-Character Cipher Mystery
The 340-Character Cipher Mystery
Knowledge check
Q1. What is the length of the 340-character cipher?
- A. 330
- B. 340 ✓
- C. 350
- D. 360
Why: The cipher is explicitly named the 340-character cipher, indicating its length.
Q2. Who is believed to be the creator of the Zodiac ciphers?
- A. Robert Graysmith
- B. The Zodiac Killer ✓
- C. Lawrence Kane
- D. David Oranchak
Why: The Zodiac Killer is believed to have created the ciphers as part of his correspondence with the police.
Q3. In which year was the 340-character cipher sent to the newspapers?
- A. 1969 ✓
- B. 1970
- C. 1971
- D. 1972
Why: The 340-character cipher was sent in 1969 as part of the Zodiac Killer's communications.
Q4. What type of cipher is the 340-character cipher believed to be?
- A. Caesar cipher
- B. Vigenère cipher
- C. Substitution cipher ✓
- D. Transposition cipher
Why: The 340-character cipher is believed to be a substitution cipher, where letters are replaced by other letters or symbols.
Q5. Which of the following is a key feature of the 340-character cipher?
- A. It contains a hidden image
- B. It uses numbers only
- C. It contains a musical note ✓
- D. It is unsolvable
Why: The 340-character cipher includes a musical note symbol, which is one of its notable features.
Module 6
Module 6: Unsolved Zodiac Codes and Theories
Unsolved Zodiac Codes and Theories
Knowledge check
Q1. What is the primary reason the Zodiac killer's ciphers remain unsolved?
- A. They were encrypted using a simple substitution cipher
- B. They contain non-standard symbols and unknown methods ✓
- C. They were solved long ago but kept secret
- D. They were written in a foreign language
Why: The ciphers use unique symbols and methods that have not been fully deciphered
Q2. Which of the following is a common theory about the Zodiac killer's identity?
- A. He was a professional cryptographer
- B. He was a former teacher
- C. He was a military veteran ✓
- D. He was a serial killer with no prior criminal record
Why: Some theories suggest the Zodiac killer had a military background, which may explain his knowledge of ciphers
Q3. Which cipher is considered the most difficult to solve by experts?
- A. The 408-character cipher
- B. The 340-character cipher ✓
- C. The 13-symbol cipher
- D. The 32-character cipher
Why: The 340-character cipher has remained unsolved for decades, making it one of the most challenging
Q4. What is the significance of the 13-symbol cipher?
- A. It was the first cipher sent by the Zodiac killer
- B. It is the only cipher that was fully solved
- C. It contains a hidden message about the killer's location
- D. It is believed to be a map or coordinate system ✓
Why: The 13-symbol cipher is thought to contain coordinates or a map reference
Q5. What is one of the main challenges in solving the Zodiac ciphers?
- A. The lack of interest from the public
- B. The absence of any known connection to the killer
- C. The use of non-standard and possibly homemade encryption methods ✓
- D. The ciphers were written in a very common language
Why: The Zodiac killer used unique and possibly homemade encryption methods, making them difficult to solve
Module 7
Module 7: Modern Techniques in Decoding Ciphers
Modern Techniques in Decoding Ciphers
Knowledge check
Q1. What is the primary purpose of frequency analysis in decoding ciphers?
- A. To determine the length of the cipher text
- B. To identify common letters or patterns in the cipher text ✓
- C. To create a new cipher
- D. To measure the complexity of the cipher
Why: Frequency analysis is used to compare the frequency of letters or symbols in the cipher text to those in the plaintext language, helping to identify common letters or patterns.
Q2. Which modern technique is commonly used to break substitution ciphers?
- A. Brute force
- B. Frequency analysis ✓
- C. Dictionary attack
- D. Reverse engineering
Why: Frequency analysis is a key technique used to break substitution ciphers by comparing the frequency of characters in the cipher text to those in the plaintext language.
Q3. What is a common weakness of the Caesar cipher?
- A. It uses a variable key length
- B. It has a small number of possible shifts ✓
- C. It is based on complex mathematical principles
- D. It is resistant to frequency analysis
Why: The Caesar cipher only has 25 possible shifts (excluding the original), making it vulnerable to brute force and frequency analysis.
Q4. What does the term 'plaintext' refer to in cryptography?
- A. The encrypted message
- B. The original message before encryption ✓
- C. The key used for encryption
- D. The algorithm used for encryption
Why: Plaintext is the original message that is encrypted into ciphertext using a cryptographic algorithm.
Q5. Which of the following is NOT a type of cipher?
- A. Substitution cipher
- B. Transposition cipher
- C. Frequency cipher ✓
- D. Vigenère cipher
Why: Frequency cipher is not a recognized type of cipher. Substitution, transposition, and Vigenère are all valid types of ciphers.