You can download an encrypted file to locally read or edit it. The file remains encrypted on the server.
How to download an encrypted file:
In the Drive app, click on a file in the detail view. In the pop-up, click the More icon . Click on Download Decrypted.
Note: If you click on Download in the pop-up instead, the downloaded file remains encrypted.
In the Enter Guard Security Password window, enter the Guard security password.
Click on OK.