CPRE 331 Midterm Exam 2024 with complete solutions

CPRE 331 Midterm Exam 2024 with complete solutions CIA Triad - ANSWERSConfidentiality - prevent unauthorized reading Integrity - Detect unauthorized writing Availability - Data is available when needed Kerckoff's principle - ANSWERSThe crypto system is completely known to the attacker Monoalphabetic cipher - ANSWERSSimple substitution but key can be any permutation of letters Easy to break because they reflect frequency data of the original alphabet Playfair cipher - ANSWERSFirst build a 5x5 table using a secret keyphrase Still a substitution cipher, but made to overcome letter frequency attacks Polyalphabetic cipher - ANSWERSCode words, Changing the shift for every letter of the code word, multiple shift by n ciphers Vigenere Cipher - ANSWERSAdd code word that is repeated to the plaintext letters Ultimate defense would be fining code word that is as long as the plaintext and holds no statistical relationship Symmetric Key Encryption - ANSWERSEncryption system in which a single key is used for both encryption and decryption. One-time pad encryption - ANSWERSA provably secure encryption method, where the ciphertext provides no info about the plaintext. Pad must only be used once, and discarded after that. You can try and decrypt, but all plaintexts will be equally likely