A database administrator needs to encrypt a large backup file before storing it in a cloud bucket. The backup is 500 GB, and the administrator wants to minimize performance impact while ensuring confidentiality. Which approach is most appropriate?

Use SHA-512 to encrypt the file and store the hash as the key.

Use RSA-2048 to encrypt the entire 500 GB file directly.

Use AES-256 in GCM mode with a randomly generated key, and store the key in a secure key management service.

Use a short 56-bit key with DES to speed up the encryption.

A software vendor wants to ensure that users can verify that a downloaded executable has not been tampered with and that it was indeed published by the vendor. The vendor has a public-private key pair. What should the vendor publish?

An encrypted copy of the executable using the vendor's private key

A digital signature of the executable

A SHA-256 hash of the executable

An online retailer wants to ensure that order confirmations sent to customers are authentic and cannot be repudiated by the retailer. The retailer has a public-private key pair. What should the retailer do with each order confirmation?

Encrypt the confirmation with the customer's public key.

Sign the confirmation with the retailer's private key.

Hash the confirmation and encrypt the hash with the customer's public key.

Encrypt the confirmation with the retailer's private key.

A security team discovers that an attacker has been measuring the power consumption of a hardware security module (HSM) during RSA decryption operations. The team needs to mitigate this side-channel attack without replacing the hardware. Which countermeasure is most effective?

Add a random delay before each decryption operation.

Use a different public key for each decryption operation.

Implement blinding in the RSA decryption process to randomize the computation.

Increase the RSA key size to 4096 bits.

A company wants to implement a system where users can encrypt files for each other without sharing a common secret. The system should also allow users to verify the identity of the sender. What should the company implement?

Symmetric encryption with a shared key

Diffie-Hellman key exchange only

Asymmetric encryption with a public key infrastructure

EC-CouncilNetwork Defense Essentials

Domain 6Objective 1

Cryptographic Techniques and Algorithms NDE Practice Questions (Page 7)

Part of the Cryptography, PKI, and Data Security domain, which makes up ~15% of our current practice bank.

39questions here

8free pages

6concepts

Questions 31–35

31application · medium
A database administrator needs to encrypt a large backup file before storing it in a cloud bucket. The backup is 500 GB, and the administrator wants to minimize performance impact while ensuring confidentiality. Which approach is most appropriate?
Select an answer first
32application · medium
A software vendor wants to ensure that users can verify that a downloaded executable has not been tampered with and that it was indeed published by the vendor. The vendor has a public-private key pair. What should the vendor publish?
Select an answer first
33application · medium
An online retailer wants to ensure that order confirmations sent to customers are authentic and cannot be repudiated by the retailer. The retailer has a public-private key pair. What should the retailer do with each order confirmation?
Select an answer first
34expert · hard
A security team discovers that an attacker has been measuring the power consumption of a hardware security module (HSM) during RSA decryption operations. The team needs to mitigate this side-channel attack without replacing the hardware. Which countermeasure is most effective?
Select an answer first
35application · medium
A company wants to implement a system where users can encrypt files for each other without sharing a common secret. The system should also allow users to verify the identity of the sender. What should the company implement?
Select an answer first

Finished these 5 questions?

Review the revealed explanations, or continue through the curriculum.

Next 5 questions →Back to NDE

Free Basic Practice is a study aid with revealable answers — not a scored exam. Examers.io is independent and not affiliated with or endorsed by EC-Council. “NDE” is a trademark of its owner, used for identification only.