Envelope Encryption

5 minutes 5 Questions

Envelope Encryption is the practice of encrypting plaintext data with a data key and then encrypting the data key itself with a different key, called the key-encrypting key or master key. It is commonly used in combination with AWS KMS to provide additional security layers while managing the encryp…

Guide for AWS KMS Envelope Encryption

Why it is important:
Envelope Encryption is an important concept in AWS KMS because it allows for the safe transmission of data. It provides another layer of security by encrypting the key that is used to encrypt data. That means the risk of compromising data is significantly reduced because even if the encrypted data is intercepted, the key to decipher it remains secure.
What it is:
Envelope Encryption is a strategy used in cryptography where a key to decipher encrypted data, also known as the 'data key', is encrypted using another key known as the 'master key'. This way the data key can be safely stored or transmitted without much risk.
How it works:
In AWS KMS, when a request to encrypt data is made, the service not only responds with the encrypted data but also returns a plaintext and an encrypted data key. The plaintext data key is used to encrypt and decrypt data while the encrypted data key is safe to be stored and transmitted as required. The data is decrypted by passing the encrypted data key to AWS KMS. The service will use the CMK to decrypt the data key, and the plaintext key is then used to decrypt the data.
Exam Tips: Answering Questions on Envelope Encryption
1. Comprehend the Basics: Ensure you understand the basic concepts and workings of envelope encryption. Questions may test your understanding of what it is and how it works.
2. Understand its role in AWS KMS: Familiarize yourself with how envelope encryption is implemented in AWS KMS and the role of CMK in it.
3. Key management: You should be aware of how AWS handles key management in the context of envelope encryption.
4. Security aspects: A good understanding of the security features and benefits of envelope encryption is essential. Questions may ask about how envelope encryption increases data security.

Test mode:

Exam (Timed)

Practice (With explanations)

Start practice test

Question 1

Scenario: A developer needs to implement client-side envelope encryption for a new web application hosted on AWS. They want to ensure the client-side secret is never stored on the server. Which AWS service can help accomplish this?

AWS Identity and Access Management (IAM) AWS Encryption SDK Amazon S3 Server-Side Encryption AWS Key Management Service (KMS)

Correct Answer: AWS Encryption SDK

The AWS Encryption SDK is best suited for implementing client-side envelope encryption because it enables the developer to perform client-side encryption with minimal modifications to the web application. It provides secure client-side encryption, ensuring the server never receives the plaintext secret key. Other services do not specifically support client-side envelope encryption.

Question 2

Scenario: You are migrating a legacy on-premises application to AWS, which relies on envelope encryption with locally managed keys for securing data. To avoid a major application redesign, what is the most effective way to transfer the existing customer master keys (CMKs) to AWS?

Import custom key material Create new AWS-managed keys Update the keys as AWS Security Group rules Store the existing keys in Amazon S3

Correct Answer: Import custom key material

In this scenario, the most effective way to transfer existing customer master keys (CMKs) to AWS is to import custom key material into KMS. Creating new AWS-managed keys would require a major redesign, and other options (storing in S3, updating as Security Group rules, using combinations, or rotating) do not provide proper key management and security.

Question 3

Scenario: You are designing the architecture for a startup's new application that requires customer data at rest to be encrypted. To minimize operational overhead, you decide to use AWS managed services. Which feature should you use for envelope encryption?

AWS CloudTrail Amazon Simple Notification Service (SNS) AWS Key Management Service (KMS) Amazon Simple Queue Service (SQS)

Correct Answer: AWS Key Management Service (KMS)

AWS Key Management Service (KMS) is designed to facilitate envelope encryption for customer data at rest. Other AWS services, such as SQS, SNS, CloudTrail, Config, and IAM, do not provide the same encryption capability.

🎓 Unlock Premium Access