Exploring the Caesar Cipher and Frequency Analysis

The video tutorial explains the Caesar Cipher, a substitution cipher used by Julius Caesar to encrypt messages by shifting letters. It describes how Alice and Bob could use this cipher to communicate securely by agreeing on a shift value. The tutorial also highlights the cipher's historical significance and its eventual vulnerability to frequency analysis, a method discovered by Al-Kindi that exploits language patterns to break the cipher.

Who is credited with the first known use of a substitution cipher?

• Napoleon Bonaparte

• Julius Caesar

• Genghis Khan

• Alexander the Great

In the Caesar Cipher, if the agreed shift is 3, what does the letter 'A' become?

• E

• D

• C

• B

What is the main purpose of shifting letters in the Caesar Cipher?

• To make the message shorter

• To make the message appear meaningless to interceptors

• To make the message more readable

• To make the message longer

How did Bob decrypt the message sent by Alice in the Caesar Cipher example?

• By adding the shift to each letter

• By multiplying the shift to each letter

• By dividing the shift from each letter

• By subtracting the shift from each letter

For how many years was the Caesar Cipher used by military leaders after Caesar?

• A few years

• Thousands of years

• Hundreds of years

• Tens of years

What is a lock breaker likely to look for when trying to break a lock?

• Material of the lock

• Size of the lock

• Color of the lock

• Mechanical flaws

Who published the weakness of the Caesar Cipher 800 years later?

• Euclid

• Pythagoras

• Archimedes

• Al-Kindi

What consistent pattern can be found by scanning text from any book?

• Sentence structure

• Letter frequency

• Word length

• Paragraph length

What is the 'fingerprint' of a language in the context of code breaking?

• The grammar rules

• The letter frequencies

• The sentence length

• The unique words used

What is the method called that involves counting letter frequencies to break a cipher?

• Frequency analysis

• Pattern matching

• Letter mapping

• Shift analysis