How secured is laravel S3 temporary URL?

I would like to know if providing temporary url to access AWS bucket objects are secured in a sense that it discloses the AWS Access Key.

From my knowing if using IAM user's access key for accessing AWS bucket rather than root Access key can be highly secured if the IAM user is only permitted to read/write S3 services.

Are there any disadvantages of providing temporary url to the public using IAM user's access key?

Regards.

via Chebli Mohamed