A security practitioner wants to encrypt a large datastore. Which of the following is the BEST choice to implement?

Symmetric encryption standards, such as the Advanced Encryption Standard (AES), are the most appropriate choice for encrypting large datastores. These algorithms are designed for high performance and computational efficiency, allowing for the rapid encryption and decryption of large volumes of data (bulk data). Asymmetric encryption is significantly slower and more resource-intensive, making it impractical for this purpose. Symmetric encryption uses a single shared key, which is optimized for high-throughput operations required for encrypting entire databases, file systems, or archives.

A. Asymmetric encryption standards: These are computationally intensive and much slower than symmetric standards, making them unsuitable for encrypting large amounts of data. They are typically used for key exchange.
C. Elliptic curve cryptography (ECC): This is a type of asymmetric encryption. While it offers strong security with smaller key sizes, it is still not designed for bulk data encryption due to performance overhead.
D. Diffie-Hellman (DH) algorithm: This is a key exchange protocol, not an encryption algorithm. It is used to securely establish a shared secret key over an insecure channel, which is then used by a symmetric algorithm.

1. National Institute of Standards and Technology (NIST) Special Publication 800-57 Part 1

Revision 5

Recommendation for Key Management.

Section 5.1

"Cryptographic Mechanisms

" Page 20: "Symmetric-key algorithms are more efficient (i.e.

faster) than asymmetric-key algorithms for protecting data. Therefore

symmetric-key algorithms are typically used to protect data (e.g.

for confidentiality or integrity)

while asymmetric-key algorithms are used to establish symmetric keys..." This directly supports using symmetric algorithms for bulk data protection.

2. Purdue University

Department of Computer Science

CS 42600

Computer Security.

"Symmetric Key vs. Public Key Cryptography" Lecture Notes: "Symmetric key crypto is much faster (100x to 1000x) than public key crypto. It is used for encrypting large amounts of data." This academic courseware confirms the performance advantage and primary use case for symmetric encryption.

3. Stallings

W. (2017). Cryptography and Network Security: Principles and Practice (7th ed.). Pearson.

Chapter 2.1

"Symmetric Cipher Model

" and Chapter 9.1

"Public-Key Cryptography and RSA": The text consistently explains that symmetric ciphers are used for encrypting large amounts of data (e.g.

a file or a database)

while public-key (asymmetric) systems are used for key management and digital signatures due to their slow performance.