You are a .NET web application developer responsible for a project that references objects stored in an S3 bucket. Previously, these objects were accessed via a public URL, but this method was flagged during a code review due to the inclusion of private data in some objects. Consequently, an administrator has made the S3 bucket private, removing public access to the objects. To address this change, you need to create an application that enables users to access specific objects via a time-restricted policy. What is the optimal solution to grant access to these objects?