Cloud-Storage: Encrypt your data optimally

Part 1 of the cloud services offered a brief overview of the online store, here I would like to deal with the optimal data protection of personal data. Usually, the files will be encrypted in the cloud, but the data itself is usually not stored encrypted, so the data of every person that has access to the online store, be read and processed unjustified.

To encrypt the data, there are several possibilities. Some providers such as Wuala cloud or offer of safe house a client-side encryption, so the password is never transmitted to the server itself and the provider has no access it. For all other cloud provider should encrypt the data before himself, before transferring to the cloud. Here, for example, TrueCrypt or BoxCryptor offer the possibility to encrypt the data first and then to transmit only in the online store.

Encrypt data with BoxCryptor

BoxCrypter is both provides for encrypting local files for the online store very popular and for all popular mobile devices (iPhone, iPad, Android) as an app. To make the data before uploading to the cloud are encrypted locally, a small overview of how can be found here:

BoxCrypter is available as an app for smartphones, as well as an application for Windows and MacOS. A standalone application for Linux is not yet available, but encryption is compatible with the open source project EncFS with which one can be decrypted encrypted with BoxEncyryptor container again (instructions can be found here).

Optimal use truecrypt for the Cloud

TrueCrypt to encrypt a free, open source software is a very popular application to data. The application is available for Windows, MacOS and Linux as well as for almost all mobile operating systems (Blackberry, iOS, Android). With the TrueCrypt whole disk or any directories can be encrypted, and there are different methods for encryption to choose, the best known is certainly the 256-bit AES method. TrueCrypt offers the possibility of automatic data synchronization, so any change to a data at the online stores is updated, but this is important to not always following setting to transfer the complete Truecrypt container in the cloud:

Under (Settings -> Preferences -> Security, there are “keeping time settings of container files” (“modifiaction Preserve timestamp of file containers”) option.

This option should be enabled to transfer only the changed files new in the cloud, otherwise the timestamp of the entire container is used, and this is thus completely transferred once again.


Cloudfogger there since 2012 and was developed for Windows and MacOS to encrypt data locally or online storage. After installation, a new directory is created on the computer while which is synchronized with the online storage (similar to Dropbox and BoxCryptor), as it is possible to release certain directories for other users who have also installed the software. Cloudfogger offers encryption for Dropbox, SkyDrive, Google Drive and others and is currently (still) available completely free of charge.


With the use of cloud storage you should be aware that access is restricted to the data in any case. It should especially be protected from outside access, if you want to access from another location or computer to the data.

You should if one carries out the encryption keys also make sure that the secret key for decryption is not lost. This is only stored on the hard drive, and this no longer works due to a defect, is also an access to the cloud data is no longer possible. So you should put the secret key will separate (possibly on a different cloud storage) or on a secure medium again.

2 thoughts on “Cloud-Storage: Encrypt your data optimally

  1. Martin

    Sehr schöner Artikel, er bietet einen sehr guten Überblick über die derzeitigen Cloudlösungen. Eine Frage hätte ich noch zu Wuala: durch die Sicherheit und clientseitige Verschlüsselung macht es die Cloudlösung zu einer der besten und sichersten Lösungen, aber wie genau funktioniert denn diese Verschlüsselung, und was passiert wenn ich mein Passwort vergessen habe?
    Aktuell erscheint es mir dass niemand (auch nicht die Mitarbeiter von Wuala) Zugriff auf die Inhalte haben, habe ich denn selbst auch keine Möglichkeit mehr auf die Daten zuzugreifen wenn ich das Passwort vergessen habe?

    Schöne Grüße,

  2. admin Post author

    Hallo Martin,
    Wuala bietet die clientseitige Verschlüsselung, d.h. bevor die Daten den Rechner über da Netz in die Cloud wandern werden diese verschlüsselt bis zur Cloud von Wuala. Es kann somit niemand außer Dir selbst auf die Daten zugreifen, auch nicht die Mitarbeiter von Wuala selbst.
    In der offiziellen Dokumentation des Anbieters steht dass Wuala selbst nur die Anzahl der Dateien sowie den benötigten Speicherplatz einsehen kann, mehr aber auch nicht. Dabei scheidet natürlich auch ein Passwort Recovery aus, d.h. falls Du selbst das Passwort nicht mehr weißt kannst Du auch nicht mehr auf die Daten zugreifen.
    Hier die Übersicht der Features in puncto Verschlüsselung:



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