A security engineer is reviewing a system that encrypts files with AES-256-GCM. The system uses a static nonce for all encryptions. What is the primary risk?

The hash function will produce collisions.

Reuse of the nonce can leak the authentication key and allow forgery of ciphertexts.

The encryption key can be derived from the nonce.

The ciphertext will be larger than expected.

A security engineer needs to ensure that configuration files downloaded from a server have not been altered in transit. The files are not secret. Which method should the engineer use?

Use a CRC-32 checksum published with the files.

Encrypt the files with AES before transmission.

Compress the files and compare the file sizes.

Publish a SHA-256 hash of each file on a separate secure channel.

A penetration tester is writing a Python script to exploit a padding oracle in a web application. The script must decrypt a captured ciphertext block. Which sequence of operations should the script perform?

Modify the previous ciphertext block byte by byte and observe the application's padding error responses.

Use a length extension attack to append data to the ciphertext.

Try all possible keys using a dictionary attack.

Replay the ciphertext to the server and capture the decrypted plaintext.

A security architect is selecting a key exchange protocol for a new VPN. The requirements are: forward secrecy, resistance to man-in-the-middle attacks, and efficient computation on low-power devices. Which protocol best meets these requirements?

RSA key exchange with certificates

GIAC Exploit Researcher and Advanced Penetration Tester

Domain 4Objective 1

Practical Cryptography GXPN Practice Questions (Page 1)

Part of the Offensive Scripting and Cryptography domain, which makes up ~18% of our current practice bank. GIAC (SANS) does not publish an official question count, but from its 180-minute exam (~70–120 total, ~13–22 in this domain), expect 7–11 from this objective — we provide 48 practice questions to prepare you well beyond it. (estimate)

48questions here

10free pages

8concepts

Questions 1–5

1foundation · easy
Which of the following is a well-known symmetric encryption algorithm?
Select an answer first
2expert · hard
A security engineer is reviewing a system that encrypts files with AES-256-GCM. The system uses a static nonce for all encryptions. What is the primary risk?
Select an answer first
3application · medium
A security engineer needs to ensure that configuration files downloaded from a server have not been altered in transit. The files are not secret. Which method should the engineer use?
Select an answer first
4expert · hard
A penetration tester is writing a Python script to exploit a padding oracle in a web application. The script must decrypt a captured ciphertext block. Which sequence of operations should the script perform?
Select an answer first
5expert · hard
A security architect is selecting a key exchange protocol for a new VPN. The requirements are: forward secrecy, resistance to man-in-the-middle attacks, and efficient computation on low-power devices. Which protocol best meets these requirements?
Select an answer first

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