Encrypting data in Lambda-based applications

Managing secrets

For applications handling sensitive data, AWS services provide a range of encryption options for data in transit and at rest. It’s important to identity and classify sensitive data in your workload, and minimize the storage of sensitive data to only what is absolutely necessary.

When protecting data at rest, use AWS services for key management and encryption of stored data, secrets and environment variables. Both the AWS Systems Manager Parameter Store and AWS Secrets Manager provide a robust approach to storing and managing secrets used in Lambda functions.

Do not store plaintext secrets or API keys in Lambda environment variables. Instead, use the AWS Key Management Service (KMS) to encrypt environment variables. Also ensure you do not embed secrets directly in function code, or commit these secrets to code repositories.

Using HTTPS securely

HTTPS is encrypted HTTP, using TLS (SSL) to encrypt the request and response, including headers and query parameters. While query parameters are encrypted, URLs may be logged by different services in plaintext, so you should not use these to store sensitive data such as credit card numbers.

AWS services make it easier to use HTTPS throughout your application and it is provided by default in services like API Gateway. Where you need an SSL/TLS certificate in your application, to support features like custom domain names, it’s recommended that you use AWS Certificate Manager (ACM). This provides free public certificates for ACM-integrated services and managed certificate renewal.