Security in Amazon S3
Important
Amazon Simple Storage Service now applies a new default bucket security setting that automatically disables server-side encryption with customer-provided keys (SSE-C) for all new general purpose buckets. In April 2026, Amazon S3 deployed an update so all new general purpose buckets have SSE-C encryption disabled for all new write requests. For existing buckets in Amazon Web Services accounts with no SSE-C encrypted objects, Amazon S3 also disabled SSE-C for all new write requests. With this change, applications that need SSE-C encryption must deliberately enable SSE-C by using the PutBucketEncryption API operation after creating a new bucket. For more information about this change, see Default SSE-C setting for new buckets FAQ.
Cloud security at Amazon is the highest priority. As an Amazon customer, you benefit from a data center and network architecture that are built to meet the requirements of the most security-sensitive organizations.
Security is a shared responsibility between Amazon and you. The shared
responsibility model
Security of the cloud
Amazon is responsible for
protecting the infrastructure that runs Amazon services in the Amazon Web Services Cloud. Amazon also
provides you with services that you can use securely. The effectiveness of our security is
regularly tested and verified by third-party auditors as part of the
Amazon compliance programs
Security in the cloud
Your responsibility is determined by the Amazon service that you use. You are also responsible for other factors including the sensitivity of your data, your organization’s requirements, and applicable laws and regulations. For Amazon S3, your responsibility includes the following areas:
Managing your data, including object ownership and encryption.
Classifying your assets.
Managing access to your data using IAM roles and other service configurations to apply the appropriate permissions.
Enabling detective controls such as Amazon CloudTrail or Amazon GuardDuty for Amazon S3.
This documentation will help you understand how to apply the shared responsibility model when using Amazon S3. The following topics show you how to configure Amazon S3 to meet your security and compliance objectives. You'll also learn how to use other Amazon services that can help you monitor and secure your Amazon S3 resources.
Note
For more information about using the Amazon S3 Express One Zone storage class with directory buckets, see S3 Express One Zone and Working with directory buckets.