For hosting common files it's ok. Also it is on Android too do, great to transfer files between your Windows and your phone. But if you want better security you have to subscribe a monthly offer.
BoxCryptor - Boxcryptor encrypts your sensitive files before uploading them to cloud storage services like Dropbox, Google Drive, Microsoft OneDrive, Box, and many others.
Dropbox - Online Sync and File Sharing
Cloudfogger - Easy and secure encryption for the cloud. Provides security for all cloud storage services like Dropbox, OneDrive and Google Drive.
Google Drive - Access and sync your files anywhere
Tresorit - Encrypted cloud storage for your confidential files. Using Tresorit, files are encrypted before being uploaded to the cloud. Start encrypting files for free.
Mega - Secure File Storage and collaboration