On an upload-by-upload basis, you create a signed manifest. This dictates what actions can be taken on an S3 bucket, e.g., the key that can be written to, the s

On an upload-by-upload basis, you create a signed manifest. This dictates what actions can be taken on an S3 bucket, e.g., the key that can be written to, the size of the files that can be uploaded. This can be used to protect against a DDoS attack.