Encryption at Rest - Amazon Polly
Services or capabilities described in Amazon Web Services documentation might vary by Region. To see the differences applicable to the China Regions, see Getting Started with Amazon Web Services in China (PDF).

Encryption at Rest

Output of your Amazon Polly voice synthesis can be saved on your own system. You can also call Amazon Polly, and then encrypt the file with any encryption key of your choice and store it in Amazon Simple Storage Service (Amazon S3) or another secure storage. The Amazon Polly SynthesizeSpeech operation is stateless and is not associated with a customer identity. You can't retrieve it from Amazon Polly later.