Efficiently Signing CloudFront Distribution URL for HLS Video Streaming Stored in S3

Hi my team is working on figuring out a solution as to how we can use signed urls to protect the content that is streamed to our users via an Alexa skill on their Alexa devices. We are serving video streaming content using HLS and m3u8 media types. The content is served through a cloudfront distribution. We have seen articles such as this which require signing the m3u8 manifest and each underlying file as well. We are looking for a more efficient alternative. Is it possible to only sign the CloudFront url? Or is the only way to serve signed m3u8 content by signing each underlying file?

Thanks!