Assessing the Risk of Brute Force Attacks on Encrypted Data at Rest

D.

An IS auditor assessing the risk of a successful brute force attack on encrypted data at rest would be most concerned about the key length.

Encryption is a process of converting plaintext into ciphertext using an algorithm and a key. There are two types of encryption: symmetric and asymmetric. In symmetric encryption, the same key is used for both encryption and decryption, while in asymmetric encryption, a pair of keys is used: a public key for encryption and a private key for decryption.

Random key generation is a good security practice that ensures that the keys used for encryption are not predictable, making it harder for an attacker to guess or brute force the key. Therefore, it would not be a concern for an IS auditor assessing the risk of a successful brute force attack.

However, the key length is crucial in determining the strength of the encryption. The longer the key, the more secure the encryption is, as it increases the number of possible combinations that an attacker would have to guess in order to decrypt the data. A short key length makes the encryption vulnerable to brute force attacks, as an attacker can try all possible key combinations until the correct one is found.

Therefore, the condition of the short key length would be of most concern to an IS auditor assessing the risk of a successful brute force attack on encrypted data at rest.