CS 320 Applied Cryptography Review Exam Q & A 2026 Complete And Study material 16pages LEARNEXAMS

1. What is the primary difference between symmetric and asymmetric cryptography? A) Symmetric uses the same key for encryption and decryption, while asymmetric uses a public and private key pair. B) Symmetric is used for digital signatures, while asymmetric is not. C) Asymmetric encryption is faster than symmetric encryption. D) Symmetric cannot be used for secure key exchange over an insecure channel. Answer: A Rationale: Symmetric cryptography uses the same secret key for both encryption and decryption, whereas asymmetric cryptography uses a pair of keys, public and private, for encryption and decryption processes, respectively. 2. Which of the following is a characteristic of symmetric encryption algorithms? A) They are generally slower than asymmetric algorithms. B) They require a secure channel for key exchange. C) They provide non-repudiation. D) They are primarily used for key distribution. Answer: B Rationale: Symmetric encryption algorithms require a secure method for key exchange because the same key is used for both encryption and decryption. If the key is intercepted during exchange, the security of the encrypted data is compromised. 3. In the context of symmetric cryptography, what does the term 'block cipher' refer to? A) A cipher that encrypts a group of bits as a single unit or block. B) A cipher that encrypts individual bits one at a time. C) A cipher that can only encrypt fixed-size blocks of data. D) A cipher that encrypts data in a chain, where each block depends on the previous one. Answer: A Rationale: A block cipher is a type of symmetric-key cipher that encrypts data in fixed-size blocks, treating each block as an independent unit of plaintext, which is then encrypted as a whole.