AWS Step Functions
Developer Guide

Encryption in AWS Step Functions

Encryption at Rest

Step Functions always encrypts your data at rest. Data in AWS Step Functions is encrypted at rest using transparent server-side encryption. This helps reduce the operational burden and complexity involved in protecting sensitive data. With encryption at rest, you can build security-sensitive applications that meet encryption compliance and regulatory requirements

Encryption in Transit

Step Functions encrypts data in transit between the service and other integrated AWS services (see AWS Service Integrations). All data that passes between Step Functions and integrated services is encrypted using Transport layer Security (TLS).