Elastic Cloud's "bring your own key" (BYOK) feature allows users to manage encryption at rest by integrating AWS Key Management Service (KMS) keys, enhancing data security and compliance. The blog outlines the process to implement this feature, starting with the creation of an AWS KMS key, setting the necessary policy settings, and subsequently using this key for encrypting data in Elastic Cloud deployments. Users can manage AWS KMS key rotation and revocation, ensuring the protection of data against potential key compromises. The detailed steps include validating the setup, managing access control through AWS Identity and Access Management (IAM) policies, and using customer-managed encryption keys. Additionally, the blog hints at future content that will cover similar encryption processes using Azure Key Vault for Elastic Cloud deployments on Microsoft Azure.