Applications process encrypted files as if they were just ordinary unencrypted files, but they can determine if a file is encrypted by using GetFileAttributes, and checking for FILE_ATTRIBUTE_ENCRYPTED.
When Mobile Encryption is enabled, users experience a slight performance hit owing to the added computational overhead.
If a memory card contains unencrypted files before Mobile Encryption is enabled—they are not automatically encrypted when the service is enabled, and therefore remain unsecured. To secure them, you must copy them to a new file on the memory card after enabling the service.
Once you have used a memory card for Mobile Encryption, the encrypted files it contains are unreadable by any device other than your mobile device. If you want to use that memory card and the memory space occupied by its encrypted files, you must delete the encrypted files.
When an encrypted file is saved to a desktop computer using ActiveSync, it is decrypted by the Encryption Filter and saved on the desktop unencrypted.
You can enable encryption for the destination folder from Folder Properties > General > Advanced > Advanced Attributes > Encrypt contents to secure data.
Mobile Encryption uses a symmetric-key algorithm for encryption and decryption. This means that only one key is used for both processes. The key is created when the device is hard reset, and is accessible by Privileged application only. If the key is ever corrupted or lost, then you will not be able to decrypt any of the encrypted files, and you will have lost your sensitive information.
By default, Mobile Encryption is configured to use the AES 128 Encryption Algorithm.
You can switch between RC4 and AES by configuring DPAPI to use the algorithm you want.
Wiping Persistent Storage results in the loss of the encryption key