Welcome - Amazon Key Management Service
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Welcome

Amazon Key Management Service (Amazon KMS) is an encryption and key management web service. This guide describes the Amazon KMS operations that you can call programmatically. For general information about Amazon KMS, see the Amazon Key Management Service Developer Guide .

Note

Amazon KMS is replacing the term customer master key (CMK) with Amazon KMS key and KMS key. The concept has not changed. To prevent breaking changes, Amazon KMS is keeping some variations of this term.

Amazon provides SDKs that consist of libraries and sample code for various programming languages and platforms (Java, Ruby, .Net, macOS, Android, etc.). The SDKs provide a convenient way to create programmatic access to Amazon KMS and other Amazon services. For example, the SDKs take care of tasks such as signing requests (see below), managing errors, and retrying requests automatically. For more information about the Amazon SDKs, including how to download and install them, see Tools for Amazon Web Services.

We recommend that you use the Amazon SDKs to make programmatic API calls to Amazon KMS.

Clients must support TLS (Transport Layer Security) 1.0. We recommend TLS 1.2. Clients must also support cipher suites with Perfect Forward Secrecy (PFS) such as Ephemeral Diffie-Hellman (DHE) or Elliptic Curve Ephemeral Diffie-Hellman (ECDHE). Most modern systems such as Java 7 and later support these modes.

Signing Requests

Requests must be signed by using an access key ID and a secret access key. We strongly recommend that you do not use your Amazon Web Services account (root) access key ID and secret key for everyday work with Amazon KMS. Instead, use the access key ID and secret access key for an IAM user. You can also use the Amazon Security Token Service to generate temporary security credentials that you can use to sign requests.

All Amazon KMS operations require Signature Version 4.

Logging API Requests

Amazon KMS supports Amazon CloudTrail, a service that logs Amazon API calls and related events for your Amazon Web Services account and delivers them to an Amazon S3 bucket that you specify. By using the information collected by CloudTrail, you can determine what requests were made to Amazon KMS, who made the request, when it was made, and so on. To learn more about CloudTrail, including how to turn it on and find your log files, see the Amazon CloudTrail User Guide.

Additional Resources

For more information about credentials and request signing, see the following:

Commonly Used API Operations

Of the API operations discussed in this guide, the following will prove the most useful for most applications. You will likely perform operations other than these, such as creating keys and assigning policies, by using the console.

This document was last published on November 25, 2021.