- Học kỳ
- SP2026
- Thời Gian
- 4/5/26
- Loại tài liệu
- PE
- Mã Đề
- CRY303c_SP26_PE2_980687
CRY303c SP26 PE RE
Q1 (1 point). (Prime Factorization): What is the prime factorization for the number 480480?
Q2 (1 point). (Caesar Cipher): You agreed to use a Caesar cipher with a key k-4. Your friend sends you: 'OCRKYCIRWS'. Decrypt the message.
Q3 (1 point). (Caesar Key Recovery): You intercepted 'KHOOR' and know the plaintext is 'HELLO'. What is the key k?
Q4 (1 point). (Permutation Cipher): Using the key [5, 2, 4, 1, 3], decrypt the ciphertext: 'RENALXRXXE'. (Remove 'X' padding).
Q5 (1 point). (Euler Totient Function): Calculate phi(1500).
Q6 (1 point). (RSA Setup): Given p = 7 q = 17 e = 5 What is phi?
Q7 (1 point). (RSA Encryption): With n = 91 ( p = 7 q = 13 ) and e = 5 encrypt M = 3.
Q8 (1 point). (RSA CCA): An attacker wants to decrypt the ciphertext C = 10 using an RSA system with parameters n = 33 and c = 3 They choose a random value r = 2 and compute the modified ciphertext C' = C.r^e (mod n) = 10.8 (mod 33) = 14. The system decrypts C' and returns M = 5 What is the original plaintext M?
Q9 (1 point). (Diffie-Hellman): In a Diffie-Hellman Key Exchange with prime p = 13 and primitive root a = 6 Alice's private key is X_{A} = 3 What is her public key YA?
Q10 (1 point). (Key Management): A corporate network is divided into 10 buildings. Each building has 2 floors, and each floor contains 5 environmental sensors. If a decentralized key distribution system is used where every sensor shares a unique pairwise key with every other sensor in the entire network, how many key exchange sessions are required?
