AES Encryption Overview Answers 1. What is a primary concern associated with symmetric-key encryption? A. It is slower than asymmetric-key encryption. B. It cannot be used for cloud storage. C. Both parties need to share the same key securely. D. It does not provide resistance to attacks. Answer: Both parties need to share the same key securely. (C) Symmetric-key encryption requires the sender and receiver to share the same key, presenting challenges in secure key distribution. 2. Which of the following describes a significant strength of the encryption method mentioned? A. It requires minimal technical knowledge to implement. B. It is resistant to all known attack methods. C. It offers fast implementation with high security. D. It ensures perfect security regardless of implementation. Answer: It offers fast implementation with high security. (C) One of the strengths of the encryption method is its efficiency, allowing for faster implementation without compromising security. 3. Which area is not typically associated with the use of strong encryption? A. Financial applications for secure transactions. B. Social media platforms for sharing personal data. C. Network security protocols for communication. D. Cloud storage for protecting data. Answer: Social media platforms for sharing personal data. (B) While social media can benefit from encryption, it is not a primary area where strong encryption is typically applied compared to financial applications or network security. 4. What is a potential weakness of using very large keys in encryption? A. They may increase resource consumption significantly. B. They offer no added security benefit. C. They make key distribution easier. D. They are immune to brute-force attacks. Answer: They may increase resource consumption significantly. (A) Using very large keys can lead to increased resource consumption, which may be considered a drawback during encryption processes. 5. Which of these is crucial for online security protocols? A. Internet security protocols. B. Simple password protection. C. User access control systems. D. Physical security measures. Answer: Internet security protocols. (A) Internet security protocols are essential components that help ensure the security of online transactions and communications. 6. What is the block size used in the AES algorithm? A. 128 bits B. 256 bits C. 512 bits D. 64 bits Answer: 128 bits (A) AES operates on blocks of data that are 128 bits in size. 7. Which of the following key sizes is NOT supported by AES? A. 256 bits B. 160 bits C. 128 bits D. 192 bits Answer: 160 bits (B) AES supports key sizes of 128, 192, and 256 bits, but does not support 160 bits. 8. What type of structure does AES use for transformations during encryption? A. Feistel Network B. Digital Signature Algorithm C. Cipher Block Chaining D. Substitution-Permutation Network Answer: Substitution-Permutation Network (D) AES uses a Substitution-Permutation Network (SPN) structure for its encryption process. 9. In AES, which operation is performed first during the cipher function? A. SubBytes B. ShiftRows C. AddRoundKey D. MixColumns Answer: SubBytes (A) The first operation performed in the cipher function of AES is SubBytes. 10. What is the main purpose of the key schedule in AES? A. To generate a fixed key for encryption B. To modify the block sizes C. To derive unique subkeys for each round D. To encrypt the data itself Answer: To derive unique subkeys for each round (C) The key schedule in AES generates unique subkeys for each round derived from the main encryption key. 11. Why is secure key management critical in AES encryption? A. It enhances the encryption speed B. It reduces the block size C. It ensures the integrity of the encryption D. It prevents initialization vector reuse Answer: It ensures the integrity of the encryption (C) Secure key management is crucial for maintaining the integrity of AES encryption against vulnerabilities. 12. Which of the following is a characteristic of AES that enhances computational efficiency? A. It requires a significant amount of memory B. It is implemented primarily in software only C. It employs hardware acceleration for faster operations D. It uses very large block sizes Answer: It employs hardware acceleration for faster operations (C) AES is often implemented with hardware acceleration to achieve faster encryption operations. 13. What is the nature of the AES algorithm in terms of its availability? A. It is highly restricted B. It is a closed-source algorithm C. It is publicly available and standardized D. It is proprietary Answer: It is publicly available and standardized (C) AES is publicly available and standardized as a symmetric-key block cipher algorithm.