Securely sync your data in the cloud

Depending on where a provider is headquartered, data privacy and data security regulations vary in how strict they are. The United States has a different approach to data privacy than Europe or Germany, for example. Under certain circumstances, U.S. law allows authorities based there to view all data and information stored in a cloud. This may apply even if the U.S. company stores the data in Europe rather than in the United States. Providers in Germany and Europe generally must comply with the European General Data Protection Regulation (GDPR) and are subject to high technical and legal requirements. 

Before you store files in the cloud, it is therefore advisable to learn about the provider.

What you should keep in mind when using the cloud:

• It is best to read the service’s terms of use carefully. Pay particular attention to whether the provider reserves the right to analyze information in your files. If so, choose a different service. 
• Choose a provider that can demonstrably guarantee that your data will be preserved and is resilient to outages. 
• There are documents you should avoid storing externally (and if you do, store them only in encrypted form). This includes files related to your health, tax documents, and bank statements. If cybercriminals hack the provider’s systems, you could otherwise be giving them easy access to sensitive data.

How cloud encryption works

In general, it is advisable to encrypt documents you store in cloud storage. Specialized software does this for you. From the operating system's perspective, nothing changes at first. You can access your data directly from Explorer or Finder as usual, and you do not need to enter a password for every document. This is known as "transparent encryption." Any changes you make sync immediately as usual, except that the files are stored encrypted on the server and only you have the key. 

All apps work on the same basic principle:

• After installing the software, first connect it to your cloud storage. 
• The software creates encrypted data containers that grow along with the storage space you need. The developers have made sure that when changes are made, only the modified files need to be synced—not the entire encrypted area.
• To access the containers, you need to use a password that is as strong as possible. Please do not use a password that you also use for other personal purposes.
• The container is automatically mounted in your operating system's file manager like an external drive. You can copy and move files in plain text. The software encrypts them and stores the encrypted data in the cloud in real time.
• You can also access your encrypted data on mobile devices, as the developers offer apps that handle encryption and decryption while you are on the go.

Examples of well-known, trusted apps for cloud encryption include:

• Boxcryptor
• Cryptomator

For experienced users – run your own cloud Do you have solid computer skills and network storage at home, or have you rented storage from a provider for your websites? Then you could run your own personal cloud. This way, you know exactly where your data is stored and can be confident that only the people you authorize can access it. All you need is the Nextcloud software, which is also available in versions for NAS systems. Setup is not difficult for experienced users, but some familiarity with a web server or network drive is needed before the system is fully configured. Thanks to its own app, Nextcloud also lets you sync files to your smartphone.