On-the-fly encryption refers to concept of disk encryption. It means that data are automatically encrypted or decrypted right before they are loaded or saved, without any user interaction. No data stored on an encrypted volume (storage card) can be read (decrypted) without using the correct password.
The files are accessible immediately after providing the password, and the entire SecuBox volume is typically mounted as if it were another storage card of the mobile device. This makes the files as accessible as any unencrypted ones. You can do anything with SecuBox secure storage card that you can do with a normal Windows CE storage card; only that with this Windows Mobile program, the SecuBox volumes require password authentication before the protected data becomes accessible.
Files can be copied to and from a mounted SecuBox volume just like they are copied to/from any normal storage card. Whenever you save information to this encrypted Windows CE storage card, it is automatically encrypted. Whenever you read information from this Windows CE storage card, it is automatically decrypted. The entire process is transparent to you.
SecuBox never saves any unecrypted data to a device or its memory card – it only stores them temporarily in the device memory (RAM). Even when the SecuBox volume is mounted, data stored in the secure card is still encrypted. When you soft-reset the device or remove the battery, the SecuBox volume will be unmounted and files stored in it will be inaccessible (and encrypted). To make them accessible again, you have to mount the volume by providing the correct password.