Encryption at rest concept in MongoDB - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

What is the main purpose of encryption at rest in MongoDB?

Encryption at rest protects data stored on disk. What does it mainly prevent?

A Unauthorized users reading data files directly from the storage device

B Unauthorized users accessing data through the MongoDB query interface

C Data loss due to hardware failure

D Data corruption caused by software bugs

💡 Hint

Think about what happens if someone steals the physical hard drive.

Encryption at rest ensures that if someone gets the physical storage, they cannot read the data without the encryption keys.

❓ query_result

intermediate

What output shows that encryption at rest is enabled in MongoDB?

After running db.adminCommand({ getCmdLineOpts: 1 }), which output indicates encryption at rest is active?

MongoDB

db.adminCommand({ getCmdLineOpts: 1 })

A {"parsed": {"security": {"enableEncryption": false}}}

B {"parsed": {"security": {"enableEncryption": true}}}

C {"parsed": {"storage": {"dbPath": "/data/db"}}}

D {"parsed": {"net": {"bindIp": "127.0.0.1"}}}

💡 Hint

Look for a security setting that shows encryption is turned on.

The presence of "enableEncryption": true under security confirms encryption at rest is enabled.

📝 Syntax

advanced

Which MongoDB configuration snippet correctly enables encryption at rest?

Choose the valid YAML configuration to enable encryption at rest with a key file.

A

security:
  enableEncryption: true
  encryptionKeyFile: /etc/mongodb/keyfile

B

security:
  enableEncryption: yes
  encryptionKeyFile: /etc/mongodb/keyfile

C

security:
  enableEncryption: true
  encryptionKey: /etc/mongodb/keyfile

D

security:
  encryption: true
  encryptionKeyFile: /etc/mongodb/keyfile

💡 Hint

Check the exact option names and boolean values.

The correct keys are enableEncryption set to true and encryptionKeyFile specifying the key file path.

❓ optimization

advanced

How can enabling encryption at rest impact MongoDB performance?

What is a common performance effect when encryption at rest is enabled?

A Lower memory usage by MongoDB

B Reduced network latency for queries

C Faster disk read/write speeds

D Increased CPU usage due to encryption and decryption processes

💡 Hint

Think about what extra work the server does when encrypting data.

Encryption requires CPU cycles to encrypt data before writing and decrypt after reading, increasing CPU load.

🔧 Debug

expert

Why does MongoDB fail to start after enabling encryption at rest with this config?

Given this config snippet, MongoDB fails to start. What is the likely cause?

security:
  enableEncryption: true
  encryptionKeyFile: /etc/mongodb/keyfile
  encryptionCipherMode: AES256-CBC

A encryptionCipherMode must be set to AES128-GCM instead of AES256-CBC

B The encryptionKeyFile path is incorrect and MongoDB cannot read the key

C The cipher mode AES256-CBC is deprecated and not supported in current MongoDB versions

D enableEncryption must be set to false to start MongoDB

💡 Hint

Check MongoDB documentation for supported cipher modes.

MongoDB deprecated AES256-CBC mode; using it causes startup failure. Supported mode is AES256-GCM.