Claris FileMaker Security Guide: Best Practices for Configuring Security Options

Encrypt container data

If database encryption is enabled for a custom app, or if container data is configured to be stored externally, all container data is encrypted by default (secure storage). If you don't want to encrypt container data when you encrypt database files or store container data externally, you can keep the container data in open storage. (However, you can't do this for files hosted by FileMaker Cloud, which requires externally stored container data to be encrypted.) See "Encrypting and decrypting database files" and "Setting up container fields to store data externally" in FileMaker Pro Help.

Notes

For files hosted by FileMaker Cloud, you can't transfer data with secure storage to embedded container data. FileMaker Cloud uses FileMaker Data Storage for container data that's configured to be stored externally.