Topic 1 Question #4
A company just learned that the data in its object storage was accessed by an unauthorized party. Which of the following should the company have done to make the data unusable?
- A.
The company should have switched from object storage to file storage.
- B.
The company should have hashed the data.
- C.
The company should have changed the file access permissions.
- D.
The company should have encrypted the data at rest.
Answer: D
The scenario describes an unauthorized access event to object storage, with the core requirement of ensuring accessed data cannot be used by the unauthorized party. This aligns with the CV0-004 Cloud+ domain of cloud data security, specifically confidentiality controls for stored data. Encryption at rest is designed specifically to protect data when an adversary gains direct access to underlying storage media or objects: it converts plaintext data to unreadable ciphertext that can only be decrypted with a controlled cryptographic key. Even if access controls are bypassed, encrypted data remains unusable to parties without the correct key, directly addressing the scenario's requirement. Option Analysis:
A. Incorrect. Switching storage types from object to file storage does not address the core issue of rendering accessed data unusable. File storage is equally vulnerable to unauthorized access leading to usable data exposure if no additional confidentiality controls are implemented, so this control is irrelevant to the scenario requirement.
B. Incorrect. Hashing is a one-way cryptographic function used for integrity verification, not confidentiality of usable data. If the company hashed its stored data, it would be unable to retrieve the original plaintext data for its own business use, making this control impractical for active storage. Hashing does not support reversible access for authorized users, so it is not a valid solution here.
C. Incorrect. File access permissions are preventive access controls that restrict who can access storage resources, but they do not render data unusable if access is successfully obtained by an unauthorized party, for example via misconfiguration, credential compromise, or insider threat. The scenario confirms unauthorized access already occurred, so permissions failed to prevent access and do not meet the requirement of making accessed data unusable.
D. Correct. Encryption at rest encrypts all data stored in object storage using cryptographic keys that are only accessible to authorized users and systems. When an unauthorized party gains access to encrypted object storage data, they only obtain unreadable ciphertext that cannot be converted back to usable plaintext without the decryption key, which is stored separately and strictly controlled. This directly meets the requirement of making accessed data unusable for unauthorized parties, per CV0-004 cloud security best practices. Key Concepts:
1. Data at Rest Encryption: A core cloud security control defined in CV0-004 objectives that protects the confidentiality of data stored on persistent cloud storage media, ensuring data is unreadable to any party without valid decryption keys even if direct access to the storage is achieved.
2. Cloud Security Control Classification: CV0-004 requires candidates to differentiate between control types: access controls such as permissions prevent access, integrity controls such as hashing verify data has not been altered, and confidentiality controls such as encryption ensure data cannot be read if accessed.
3. Breach Impact Reduction: A key CV0-004 data protection objective is implementing controls that limit the impact of a successful unauthorized access event; encryption of sensitive data is a primary control for reducing breach severity by rendering exfiltrated data unusable. References:
CompTIA Cloud+ (CV0-004) Exam Objectives, AWS Encryption at Rest Whitepaper