CSX CSX Cryptography and Data Protection 1 — Questions and Answers
Question 1: What is the primary difference between symmetric and asymmetric encryption?
- Symmetric uses two keys; asymmetric uses one key
- Symmetric uses one shared key; asymmetric uses a public/private key pair (Correct answer)
- Symmetric is slower than asymmetric encryption
- Asymmetric cannot be used for bulk data encryption
Correct answer: Symmetric uses one shared key; asymmetric uses a public/private key pair
Symmetric encryption uses a single shared key for both encryption and decryption, while asymmetric uses a mathematically linked key pair.
Question 2: Which hashing algorithm is currently recommended by NIST for producing a 256-bit digest?
- MD5
- SHA-1
- SHA-256 (Correct answer)
- DES
Correct answer: SHA-256
SHA-256, part of the SHA-2 family, is NIST-recommended and produces a 256-bit hash, unlike the deprecated MD5 and SHA-1.
Question 3: What is the purpose of a digital certificate in public key infrastructure (PKI)?
- To encrypt hard drives
- To bind a public key to an identity, verified by a Certificate Authority (Correct answer)
- To generate symmetric session keys
- To store private keys securely in hardware
Correct answer: To bind a public key to an identity, verified by a Certificate Authority
A digital certificate issued by a CA associates a public key with an identity, enabling trust in encrypted communications.
Question 4: Which encryption standard is federally approved in the US for protecting classified and sensitive government data?
- DES
- 3DES
- AES (Correct answer)
- RC4
Correct answer: AES
AES (Advanced Encryption Standard) is NIST-approved and used by the US government for protecting classified information.
Question 5: What is a rainbow table attack and which control best mitigates it?
- A brute-force attack mitigated by longer passwords
- A precomputed hash lookup attack mitigated by password salting (Correct answer)
- A replay attack mitigated by session tokens
- A dictionary attack mitigated by multi-factor authentication
Correct answer: A precomputed hash lookup attack mitigated by password salting
Rainbow tables are precomputed hash databases; adding a unique salt to each password before hashing defeats this attack.
Question 6: In TLS, what is the role of the handshake protocol?
- To transfer encrypted application data
- To negotiate cipher suites and establish session keys between client and server (Correct answer)
- To verify file integrity after download
- To compress data before transmission
Correct answer: To negotiate cipher suites and establish session keys between client and server
The TLS handshake negotiates protocol version, cipher suites, authenticates parties, and establishes session encryption keys.
CSX CSX Cryptography and Data Protection 1
What is the primary difference between symmetric and asymmetric encryption?