Encrypting Files in Sensitive Directories with Symmetric Key

B.

The correct answer is B. TwoFish.

Explanation:

Symmetric-key encryption, also known as shared-secret encryption, is a type of encryption that uses the same key for both encryption and decryption. In this scenario, the files in several sensitive directories of a file server will be encrypted with a symmetric key. This means that the same key will be used to encrypt and decrypt the files.

RSA is an asymmetric encryption algorithm that uses a public and a private key for encryption and decryption, respectively. It is not a symmetric encryption algorithm, so it cannot be used in this scenario.

Diffie-Hellman is a key exchange protocol used to securely exchange keys between two parties. It is not a symmetric encryption algorithm, so it cannot be used in this scenario.

NTLMv2 is a protocol used for authentication in Microsoft networks. It is not an encryption algorithm, so it cannot be used in this scenario.

RIPEMD is a hash function used to generate message digests. It is not an encryption algorithm, so it cannot be used in this scenario.

TwoFish is a symmetric-key block cipher that can encrypt data in blocks of up to 256 bits using a key of up to 256 bits. It is a strong encryption algorithm that is widely used and has been approved by various standards organizations. It is an appropriate choice for encrypting sensitive files in a file server with a symmetric key.

In conclusion, the correct answer is B. TwoFish.