Bitcatcha's content is reader-supported. When you purchase through links on our site, we may earn an affiliate commission. Learn more

What Is Zero-Knowledge Encryption? (Does It Keep Your Cloud Storage Data Private?)

Jao Gavino
June 17, 2024


Let’s face it: cloud storage is one of the best ways to keep your data safe today. That is – as long as it’s offering adequate security features.


If you want a cloud platform that provides both peace of mind and convenience, zero-knowledge encryption could be exactly what you’re looking for.


But what is zero-knowledge encryption? How does it work? If you want the answers to all of these questions (as well as the best cloud storage providers that we’ve found), read on!



What Is Zero-Knowledge Encryption?


Zero-knowledge encryption is a form of encryption that allows you to store data in the cloud without sharing your encryption key with the cloud storage provider.


It’s called “zero knowledge” because the cloud provider has no knowledge of your encryption key (and hence your data), ensuring that no one except you can gain access.



How encryption works


example of how encryption works on a text

These two documents contain the same information. However, one document is encrypted, and the other isn’t.


Before we go into more detail about how zero-knowledge encryption works, you’re going to have to have a basic understanding of how encryption works. When you upload anything to the cloud, it is usually encrypted by the cloud storage provider as part of its security measures.


Without such encryption, anybody that breaks into your cloud storage can look at your files and see them plainly for what they are, whether they’re a ZIP archive of embarrassing high school photos or your company’s entire client database.


With encryption, however, your files will appear as strings of random data, numbers, symbols, and so on—ensuring that if anyone gets their hands on them, they’ll have a very difficult time making any sort of use of them.


To decrypt these files, you’re going to need a key, which tells the computer how to decrypt all of that encrypted data, turning it into something that you can use, such as a document, picture, and so on.


How zero-knowledge encryption works


The way that zero-knowledge encryption works has to do with who possesses this key. With zero-knowledge encryption, only you will have access to your encryption key. Not even your cloud storage provider will have access to it.


This ensures that nobody other than you will be able to access the data that you upload, making zero-knowledge encryption one of the strongest data protection measures that you can take.


This encryption key usually comes in the form of a password, which isn’t stored anywhere by the cloud provider, making sure that you’re the only one who knows this password (and therefore the key to decrypt your data). You simply type in your password, and your data gets decrypted.


The Pros and Cons of Zero-Knowledge Encryption


hacker wearing a mask

Zero-knowledge encryption ensures that only you hold the key to decrypting your files—safeguarding them from any online hooligans.


Like all things, this type of encryption has its advantages and disadvantages. For example, one advantage that zero-knowledge encryption has is that it prevents anyone other than you from accessing your files.


This means that whatever you upload to the cloud is safe from cybercriminals, government snooping, and rogue employees because as the name implies, they have zero knowledge. Given this, zero-knowledge encryption is one of the strongest ways of safeguarding your data.


On the other hand, one downside to zero-knowledge encryption is that, like all humans, you can forget. If you forget your password, that’s it—say goodbye to all of your files.


The same goes if your password gets stolen somehow. If someone gets access to your personal key, they’ll be able to access your encrypted files.


One other negative to this type of encryption is that not all cloud storage services offer zero-knowledge encryption. If you’re wondering which services offer zero-knowledge encryption, we’ll be sharing three of them in a bit!



How Is It Different From End-To-End Encryption?


three gears with padlock at the end and fingerprint in the middle

In E2EE, your data is encrypted at the source (you) and then decrypted at its destination (the cloud).


You may have also heard about end-to-end encryption (E2EE) while researching encryption. Simply put, in end-to-end encryption, your data is encrypted before being sent to another party, where it is then decrypted.


This method of encryption prevents any hackers or sneaky government agents from viewing your files while they are in transit. However, E2EE can only be utilized when there is a receiving party (e.g., your cloud provider) for your information.


On the other hand, in zero-knowledge encryption, your data is encrypted before it’s sent, and that data will remain encrypted even when it’s received by the other party. This guarantees that nobody except you will be able to access your data, ensuring the utmost security and privacy of your files.


Think of zero-knowledge encryption as a step above E2EE: your data remains encrypted throughout the whole process, and there’s only one point of failure—you. If you forget your password or get lax with it, you can pretty much kiss your data goodbye.



The Best Cloud Storage Services With Zero-Knowledge Encryption


If you’re looking to use a cloud storage service that offers zero-knowledge encryption, here are three of the best options that we’ve found:


1. – Best in security homepage rises above the competition with its extensive suite of security features.


It should come as no surprise that — one of the most secure cloud storage providers that we’ve found—offers zero-knowledge encryption. Sync offers 5 GB of storage for free, and its paid options start at $8 per month for 2 TB of storage.


In addition to zero-knowledge encryption, Sync also follows international privacy laws, such as the US HIPAA, Canadian PIPEDA and PHIPA, and European GDPR, certifying the safety and privacy of your data even further.


Sync also offers a bevy of other security features, such as remote file wipes, 2-factor authentication, and even expiry dates for your shared files. Simply put, if you want the very best in privacy, accept no substitutes — is the best choice for you.


2. pCloud – Best in versatility


pCloud homepage

pCloud offers a wider array of functionalities for its users.


Next, we have Switzerland-based pCloud, which offers 10 GB of free storage, with premium versions starting at $4.17 per month for 500 GB. However, if you want zero-knowledge encryption, you’re going to have to pay an extra $49.99 per year.


Alternatively, pCloud offers a lifetime plan option—for a one-time $199 payment, you’ll have permanent access to 500 GB of expandable storage. If you want a lifetime pricing option for zero-knowledge encryption, that’ll cost you an additional $150.


At these prices, pCloud offers you an extremely versatile collection of features, such as online backups, custom file syncing, and virtual drives, which all come wrapped up in an easy-to-use interface.


pCloud also works on nearly all devices and platforms, including MacOS, Windows, Android, iOS, and even Linux!


We’d recommend pCloud for users that want to do plenty of other things with their cloud storage (not just security), such as web hosting, in addition to the many features that we’ve mentioned above.


3. Icedrive – Best in affordability


Icedrive Main Website

Icedrive is a relative newcomer to cloud storage, but it offers the lowest prices among all of the cloud providers that we’ve reviewed.


Finally, Icedrive is another cloud service that offers a zero-knowledge encryption policy. One of Icedrive’s strongest selling points, however, is its pricing: it offers 10 GB of free storage, and 150 GB of storage will only cost you $1.67 per month.


At the same price point as pCloud ($4.17), Icedrive will give you a massive 1 TB of storage—that’s double what pCloud offers. Plus, all of these options come with zero-knowledge encryption free of charge.


With all of these advantages, you may be wondering, “What’s the catch?” To be honest, there isn’t one—security-wise, Icedrive even uses the Twofish algorithm, which is a more secure form of encryption compared to AES. Like pCloud, Icedrive even offers a lifetime pricing option, which starts at $99 for 150 GB of cloud storage.


However, one downside to Icedrive is that it’s relatively new to the cloud storage market. As such, it doesn’t offer some of the features that more established providers have, like the option to choose between selective sync or block-level sync.


If you don’t mind these minor limitations, however, and just want the cheapest option without compromising your files’ security, then look no further than Icedrive!



(Zero-)Knowledge is Power!


As you can see, zero-knowledge encryption is one of the most secure ways to keep your data private. And with our tips and recommendations, you’re more than ready to make use of such encryption to ensure the safety and privacy of your data!