Symmetric Cryptography and Key Algorithms BDC Practice Questions (Page 6)

Questions 26–30

1. 26expert · hard

   A company is designing a secure messaging app that needs to encrypt messages between two parties. They want to use a symmetric algorithm that is fast and provides authenticated encryption. They are considering AES-GCM and ChaCha20-Poly1305. Which factor should most influence their choice?

   • AThe block size of the underlying cipher.
   • BThe complexity of the algorithm's implementation.
   • CThe availability of hardware acceleration on the target devices.
   • DThe key length of the algorithm.
   Reveal Solution Discussion Select an answer first
2. 27application · medium

   A company is considering using symmetric encryption for a new application that will be used by thousands of users. The application will allow users to share encrypted files with each other. What is the primary limitation of using symmetric encryption in this scenario?

   • AThe inability to use symmetric encryption for data at rest.
   • BThe lack of support for authenticated encryption in symmetric algorithms.
   • CThe difficulty of securely distributing a unique key to each pair of users.
   • DThe speed of encryption is too slow for large files.
   Reveal Solution Discussion Select an answer first
4. 28foundation · easy

   What is a primary advantage of symmetric cryptography over asymmetric cryptography?

   • AIt is computationally faster and more efficient for bulk data encryption.
   • BIt eliminates the need for key distribution.
   • CIt allows two parties to communicate without ever sharing a secret.
   • DIt provides stronger security for the same key size.
   Reveal Solution Discussion Select an answer first
5. 29expert · medium

   A security engineer is troubleshooting a system where encrypted data is corrupted during transmission. The system uses AES-CBC without authentication. The engineer wants to detect corruption and ensure integrity. What is the best solution?

   • AUse AES-ECB instead
   • BAdd a checksum to the ciphertext
   • CUse AES-CBC with a fixed IV
   • DSwitch to AES-GCM
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6. 30foundation · easy

   Which block cipher mode of operation encrypts each block independently, meaning identical plaintext blocks produce identical ciphertext blocks, and is therefore not recommended for most uses?

   • AGCM
   • BCBC
   • CECB
   • DCTR
   Reveal Solution Discussion Select an answer first