What is AWS Key Management Service (AWS KMS)?

AWS KMS simplifies creating and managing keys for data protection. It is one of the important components used by Amazon Web Services to securely keep data confidential and maintain its integrity across all of your AWS workloads. This blog discusses extensively about what AWS Key Management Services is and what training options are available for techies.

What is AWS Key Management Service (AWS KMS)?

It is a service that allows users to efficiently create, manage, and control keys that protect data. AWS KMS will allow you to encrypt data in transit and at rest within your AWS environment using all AWS services.

Hardware Security Modules (HSM)

Essentially, AWS KMS uses HSMs to securely store and asynchronously validate your keys under the auspices of the FIPS 140-2 Cryptographic Module Validation Program. This means your keys are safe and open only to those users or services you permit.

Automated Updates

AWS KMS also provides another feature known as the automatic key rotation whereby the cryptographic material is updated, and the user never has to go for the update manually. Lastly, there is good from the AWS side; AWS KMS has integrations with AWS CloudTrail, providing detailed logs of key utilization, audit, and compliance reporting.

Management Controls

You can create and control keys in your AWS CloudHSM cluster or external Key Management Service, which allows you to meet specific regulatory or security needs. AWS KMS also supports multi-region keys, so you can encrypt in one AWS Region and decrypt in another, which is crucial for data replication and disaster recovery.

Identity and Access Management (IAM)

AWS Identity and Access Management (IAM) is also integrated into AWS KMS to perform fine-grain access control; that is, only certain users and services are allowed to access your keys.

What is a key in AWS KMS?

AWS Key Management Service, or KMS key, forms an integral component of AWS KMS and is utilized for managing cryptographic keys that your applications might use in the cloud. The KMS keys handle everything related to the data’s encryption and decryption process, which, in turn, keeps the data safe during rest and transit.

KMS Keys Types:

• Symmetric Keys: It use the same key for encryption and decryption and usually follow the AES-256 encryption standard. They are suitable for most everyday encryption needs.
• Asymmetric Keys: Asymmetric keys use a public and private key pair for encryption, decryption, or signature and verification. These keys are used in situations requiring public critical infrastructure or PKI.

Key Features:

• Metadata: This is the metadata associated with the KMS key, such as the key ID, the date it was created, and its current state.
• Key Material: The actual cryptographic key material is kept and managed by AWS KMS secure and safe.
• Integration: The AWS Key Management Service easily integrates with other AWS services, such as S3, EBS, RDS, etc., for enhanced encryption capability.

Security:

AWS KMS keys are protected by hardware security modules that provide highly secure and compliant encryption technology. You can also grant access and set the permission via AWS IAM.

For more information on this critical cloud security feature, check out Edureka’s AWS tutorials online.

Symmetric, Asymmetric, and HMAC Encryption Keys in AWS KMS:

AWS KMS keys are the primary resource for encrypting, decrypting, and re-encrypting data. What’s more, you can also generate data keys for use outside of AWS KMS. While symmetric KMS keys are commonly used, you can create asymmetric KMS keys for encryption or signing and HMAC KMS keys for generating and verifying HMAC tags. The difference between the three types of keys is one of the most common AWS interview questions asked by prospective employers looking for cloud computing professionals.

Symmetric KMS Keys

These represent a 256-bit AES-GCM encryption key (or 128-bit SM4 key in China Regions). Symmetric keys are the default type and are the most frequently used, remaining encrypted within AWS KMS.

Asymmetric KMS Keys

Represent a public and private key pair, where the private key stays encrypted within AWS KMS. While RSA key pairs are common for either encrypting data or signing messages, elliptic curve keys, on the other hand, can be used for signing messages or deriving shared secrets.

HMAC KMS Keys

These represent a symmetric key used for generating and verifying hash-based message authentication codes (HMAC). The HMAC keys also remain encrypted within AWS KMS.

Key material in AWS KMS

KMS in AWS refers to the bits utilized in cryptographic algorithms. Secret key material must remain confidential to safeguard the operations that depend on it, while public key material is intended for sharing.

Each KMS key includes a reference to its key material within its metadata. The source of the key material for symmetric encryption KMS keys can vary. You can choose to use key material generated by AWS KMS, key material from an AWS CloudHSM cluster in a custom key store, or your own imported key material. If you select AWS KMS-generated material for your symmetric encryption key, you will have the option to rotate key material automatically.

By default, every KMS key has a unique material. However, you can create multi-Region keys that share the same material across different regions.

Creation and Management of AWS KMS Keys

AWS KMS allows organizations to create, modify, view, enable, disable, and delete symmetric and asymmetric KMS keys, including HMAC keys. They can also create, delete, list, and update aliases (aka friendly names) for KMS keys, which makes using and managing access much easier.

AWS KMS has key policies, IAM policies, grants, and tags to regulate who can access what keys. Tags help in identifying, automating, and tracking the costs of KMS keys. In addition to IAM, AWS KMS supports attribute-based access control (ABAC) using tags and aliases as well as condition keys to further narrow the scope of policies. Furthermore, users can enable automatic key material rotation.

Envelope Encryption in AWS KMS

Securing the encryption key is equally important when encrypting data. A widely used method is envelope encryption, which involves encrypting plaintext data with a data key and then encrypting that data key with another key.

You can even encrypt the data encryption key with multiple layers of encryption keys. However, one key must ultimately remain in plaintext to decrypt everything else. This top-level plaintext key, which is used to decrypt the keys and the data, is referred to as the root key.

Envelope encryption takes advantage of this strength..

AWS KMS Integrations

AWS KMS integrates with nearly all AWS services that encrypt enterprise data. Only symmetric encryption KMS keys are used by AWS services integrated with AWS KMS to secure data. When organizations integrate AWS services with AWS KMS, they can utilize the KMS keys in their account to safeguard the data handled, stored, or managed by these services.

Some integrations with AWS KMS include:

• AWS CloudTrail
• Amazon DynamoDB
• Amazon EBS
• Amazon EMR
• Amazon RedShift
• Amazon RDS
• Amazon S3
• WorkSpaces

Conclusion

Security is of the utmost concern for anyone handling corporate data, and AWS KMS was designed to simplify encryption. It is much more than mere access control. Because it supports encryption tools in and outside the cloud, AWS KMS protects one’s data while maintaining compliance with the environment. Obtaining AWS certification and learning to use AWS KMS for security ensures you get the skills you need to set up a cost-effective way to safeguard your data.

FAQs

What is AWS KMS?

AWS KMS is a managed service that enables you to create, control, and utilize encryption keys to encrypt and decrypt data across AWS services.

What is AWS KMS used for?

The AWS Key Management Service, or KMS, enables one to easily encrypt data in rest and transit with confidentiality and integrity across AWS workloads.

What is the difference between AWS KMS and Secrets Manager?

AWS KMS manages encryption keys for data security, while Secrets Manager handles the storage and rotation of credentials like passwords and API keys.

What is the difference between CMK and KMS?

AWS KMS is one of the services responsible for key management in data encryption, whereas CMK stands for Customer Master Key, a type of key managed within KMS.