But, before we start, if you don't know what a Cloud drive is, you can see my earlier post that explains all about them, here.  

The main security risk of Cloud drives is that if somebody else gets access to your laptop or your mobile device it may be possible for them to access the files in your Cloud-drive through your devices – just as it would be possible for them to get access to any files that you have stored locally on your devices.  

Also, as all of the Cloud drives can be accessed through a web page interface, anyone who has your Cloud-drive account login details can access your files.

For a Cloud drive app that is installed on your laptop, there is no direct security for the files stored in your Cloud drive because a copy of all of your Cloud-drive files is stored locally in the folders on your laptop’s hard disk drive. For these files to be secure you must rely on your laptop's security, that is, on your login password on your laptop.   

Of course, you don’t have to install a Cloud drive app on your laptop to use your Cloud drive service; you can just access your files through the Cloud drive’s web page interface in a browser.

For your mobile devices, unless you have set up some of your files as offline files, people with access to your device won't be able to get to your Cloud-drive files unless they can connect your device to the internet, which, however, usually isn't too difficult.

For OneDrive or Dropbox mobile-device apps you can set an access password to keep your files secure; so files stored in these Cloud drives can be secure even if you don't have a password on your mobile device.

This is not so for Google Drive; Google Drive has no access password protection and so relies on your mobile device’s security.  If you are using the Google Drive app you should set a password for opening your mobile device, which is a pretty good idea, regardless. 

So that’s what you can do to ensure the security and safety of your data – but what about the other side of the fence? How secure and safe are Microsoft, Google, and Dropbox with your data?

In terms of keeping your data safe, I expect that all three cloud service providers will be using the best technology available to make sure that they don't lose your files – they certainly claim that they do.

Personally, I believe that for a normal traveller like me, and probably like you, who aren't holding state or commercial secrets, and who aren't organising any terrorist activities, all three of these providers are perfectly secure.  It may be possible that the US Government, or possibly even the Australian Government, could require these companies to hand over our photos and travel documents: but that’s not likely to happen, and it probably won’t be more than an embarrassment to you (because you’ve taken so many selfies) if they do.

You can read what each of these service providers have to say about their security and safety here on their websites:

Dropbox security

Google Drive security

OneDrive security

And if you're still worried, here’s an article that won't quell your fears at all!