Encoding
Q: What is the purpose of encoding?
A: To make data easier to store, read, or transfer.
Q: How many bits are in a byte?
A: 8.
Q: What do we call readable text before encryption?
A: Plaintext.
Q: What kind of cipher rearranges letters but doesn’t change them?
A: Transposition.
Q: What does steganography hide?
A: The existence of the message.
Q: Is encoding meant to provide confidentiality?
A: No — it does not hide meaning from attackers.
Q: Convert binary 01000001 to ASCII.
A: 65 → ASCII “A”.
Q: What do we call unreadable, encrypted text?
A: Ciphertext.
Q: What kind of cipher replaces letters with other letters?
A: Substitution.
Q: What type of file most commonly hides data?
A: Images.
Q: What character set maps letters to decimal, binary, and hex?
A: ASCII
Q: What base is hexadecimal?
A: Base 16.
Q: What is an algorithm in cryptography?
A: A set of instructions for encryption/decryption.
Q: What is another name for the Caesar Cipher?
A: Shift cipher.
Q: What tool lets you see metadata inside a picture?
A: Exif Viewer.
Q: Base64 uses how many characters?
A: 64 characters (A–Z, a–z, 0–9, +, /).
Q: Convert hex 3A to decimal.
A: 58.
Q: What does cryptanalysis mean?
A: Attempting to break a cipher.
Q: In a shift‑2 cipher, what does “E” become?
A: G.
Q: What tool can find hidden files inside another file?
A: Binwalk.
Q: What is the difference between encoding and encryption?
A: Encoding = formatting for computers;
Encryption = securing data with a key.
Q: Convert hex FF to decimal.
A: 255.
Q: Why is the One‑Time Pad unbreakable?
A: Uses a random key equal to the message length & used once.
Q: What makes Vigenère a polyalphabetic cipher?
A: It uses multiple alphabets based on a repeating key.
Q: Why is steganography hard to detect?
A: The image/file looks unchanged; hidden bits aren’t visually noticeable.