We've (almost) all embraced cloud services. Yet, have you ever wondered, "Can my cloud provider see my files?" This isn't just techno-paranoia but a genuine concern. Let's look at how cloud storage may not be as private as you think.

How Cloud Storage Works

Think of cloud storage as your computer's hard drive but magnified enormously and accessible over the internet. When you save a file to the cloud, you rent space in a gigantic, digital apartment complex where each file is like a tenant.

Your data is diced up, stored across various physical locations, and processed in accordance with data security and privacy standards. While it's improbable that your data will ever go AWOL, keeping local backups is still a good idea because, let's face it, accidents do happen!

The Lowdown on Data Privacy in the Cloud

When we hand over our precious data to cloud services, it's natural to consider privacy issues. Could the cloud service providers take a sneaky peek at your files? Well, the answer isn't straightforward.

There are two crucial aspects to consider: legal obligations and technical possibilities. Cloud providers are tied down by their privacy policies and local data protection laws. For instance, the General Data Protection Regulation (GDPR) in Europe can slap heavy fines on providers who unlawfully access a user's data.

Nonetheless, we can't overlook the technical feasibility of ogling your info. A cloud storage provider accessing your unencrypted files is a real possibility, much like a landlord could hypothetically walk into your rented apartment at any time, regardless of what the local entry-notice laws state. But what about random outsiders? That's where encryption comes into play.

Encryption 101: Securing Your Files in the Cloud

Encryption is like a magical spell that turns data into an indecipherable script. It makes data unreadable to anyone without the magic key (or decryption key, in less fantasy-laden terms). Two primary encryption methods are associated with cloud storage: "at rest" and "in transit."

"At rest" encryption is when your data, stored on your cloud provider's server, is encrypted, rendering it nonsense to anyone physically accessing the server without the decryption key. So if a hacker manages to download those files, they still can't see what's in them.

"In transit" encryption, on the other hand, safeguards your data as it journeys from your device to the cloud server and back. It's like mailing a coded message - even if the package is intercepted, the message inside remains unintelligible without the decryption key.

These methods do an excellent job of keeping nosy third parties at bay, but what about the cloud provider with the decryption keys? They could easily read your data if they wished to.

To counter this, some privacy-centric providers offer "zero-knowledge" encryption. With this approach, the cloud provider doesn't have the decryption key, making it technically impossible for them to read your data. Notable examples include Sync.com and Mega.io.

You can also practice your own in-house encryption magic and protect your data by encrypting files before uploading them to the cloud. An extra layer of protection ensures that your files remain unreadable to prying eyes.

Can Your Cloud Provider Really Access Your Files?

After that (semi) deep dive into the world of cloud storage, it's clear that the answer is, mostly, "yes." Unless you're using a zero-knowledge provider, cloud providers could peruse your files if they really wanted to.

Many of the handy features you enjoy in the cloud, like searching the contents of your Google Docs files, or the miraculous ability to search "cats" in Google Photos and find every feline photo you ever snapped, are possible because of this access.

Yet, rest assured, these functions are operated by software; no human is supposed to be peering into your data. Still, laws and privacy policies are just that - words on paper. They can't stop a breach, only offer you a path for recourse if the worst should happen.

Therefore, think twice about what you send into the cloud. Consider a zero-knowledge service or encrypt your files before hitting the upload button. Remember, it's better to be safe than sorry in the digital world.

Has It Actually Happened?

We've established that cloud providers could look at the contents of your data in a way that breaches your privacy in theory, but has it actually happened? Well, for obvious reasons, it can be difficult to actually prove that this is happening within the walls of cloud providers, but there have been worrying cases where customer cloud data has made it into the hands of regular employees.

According to one report, staff at Ring watched and shared videos recorded by customer devices. In 2019, it was reported that the Desjardins Group had suffered a massive data breach, caused by an employee who exposed the private information of about 2.9 million people. In 2018, Facebook (now Meta) fired an employee for allegedly abusing their data access privileges to stalk female users. These are just a handful of examples and come from incidents that we know about without any true indication of how often the custodians of our cloud data are tempted to take a peek.

If you want to protect yourself, look for those cloud storage providers that provide zero-knowledge encryption. If you've got the technical chops, you could also host your own cloud server with Nextcloud, where absolutely no one but you has access to it. And, ultimately, if something is so sensitive that you would be devastated, be it socially, emotionally, or financially, if it was leaked, then consider encrypting it using your own methods before uploading it or not uploading it all and relying on local encrypted backups.

Related: The Best Cloud Storage Services of 2023