Cryptography Techniques and Concepts

What is the primary distinction between steganography and cryptography?

• Steganography hides the existence of a message, while cryptography hides its meaning.

• Steganography rearranges letters, while cryptography replaces them.

• Steganography is an ancient technique, while cryptography is a modern invention.

• Steganography uses physical concealment, while cryptography uses mathematical algorithms.

How did the Spartan Skytale cipher work to conceal messages?

• A leather strip was wrapped around a wooden rod, and the message was written along the rod, appearing jumbled when unwrapped.

• Letters were replaced with other letters based on a secret keyword.

• Messages were hidden under a layer of wax on a wooden board.

• The message was rearranged into an anagram that only the sender could decipher.

What is the primary vulnerability of a simple Caesar Shift Cipher?

• It requires a complex keyword that is difficult to remember.

• The limited number of possible shifts makes it susceptible to brute-force attacks.

• It hides the existence of the message, making it easily discoverable.

• The message becomes too long and difficult for the intended receiver to untangle.

What was Al-Kindi's significant contribution to cryptanalysis?

• Inventing the first mechanical encryption device.

• Developing the concept of public-key cryptography.

• Pioneering the use of frequency analysis to break ciphers.

• Creating the first polyalphabetic substitution cipher.

What is a primary limitation of using frequency analysis for cryptanalysis?

• It only works for short messages.

• It is ineffective against ciphers that use symbols instead of letters.

• Its effectiveness is reduced when the text has an unusual distribution of letters.

• It requires a known plaintext to be successful.

Which of the following techniques was introduced during the Renaissance to make ciphers more difficult to break?

• One-time pads

• Quantum encryption

• Nulls and intentional misspellings

• Enigma machines

What is the fundamental difference between a code and a cipher in cryptography?

• Codes replace words, while ciphers replace letters.

• Codes are used for encryption, while ciphers are used for decryption.

• Codes are digital, while ciphers are analog.

• Codes are public, while ciphers are secret.