Google Drive/Dropbox like solutions with Offline access and local security and Cross Platform
===

Are there any software solutions or SDKs parts that handle the following:

- Propose something like google docs or dropbox, with secured storage for enterprise
- Documents are stored for offline access
- Documents are encrypted
- Solution work on iOS, Android and if possible Windows / Mac OS


I know that google docs will propose offline access and distribute an application on IPad but I would like to know if there are alternatives ?


Thank you

Regards
