Digital data storage is essential nowadays. We store all types of data in our devices, either in local storage or using cloud storage services. Cloud storage services have several advantages, such as data sharing among devices, space-saving in local storage, and data preservation in case of user device’s hardware failure. However, those services come with associated risks, which users often are not aware of, such as temporary/permanent data unavailability or loss of confidentiality. We propose a secure file storage system based on public cloud services that mitigates these risks by combining the use of multiple cloud providers with redundancy mechanisms and cryptographic techniques. The system ensures that, even if one provider is hostile or goes out of business, there is no loss of data or confidentiality. A performance penalty is paid when compared to a plain cloud storage service, but is acceptable in face of the additional guarantees.