How should a Confluence backup be validated before restoration?

Before restoring a Confluence instance from a backup, it is necessary to confirm that the archive is intact and contains the expected data, but it is unclear which combination of checks provides the strongest assurance against corruption. The validation process must balance speed with thoroughness, especially when dealing with large backup files in a staging environment.

Which checksum algorithm (e.g., SHA-256, MD5) offers sufficient confidence for detecting alterations in a Confluence backup? How can a test restore be executed in an isolated staging instance without risking production data? What specific log messages or application behaviors indicate that the backup has been successfully restored and that key content such as spaces, users, and attachments is accessible?