iTwin File Access with SecureBox (Gunmetal Gray) iTwin SecureBox works seamlessly with Dropbox(TM) account and uses AES 256-bit encryption, in AES-GCM mode, the encryption-key residing only on the iTwin halves. All file transfers using iTwin Remote Access are encrypted end-to-end with an AES-256 bit encryption-key stored only in the halves. A unique Disable Code prevents unauthorized access to your data through a Remote Disable feature. Drag & Drop Simplicity and Plug & Play Operation to Upload/Download/Edit your files/folders. No Subscription fees. No limits on data size. Works with Microsoft Windows XP, Microsoft Windows Vista, Microsoft Windows 7, both 32-bit and 64-bit versions, Mac OS X Snow Leopard, OS X Lion and OS X Mountain Lion.