As the cloud becomes increasingly popular for daily use, cybercriminals have started to focus on infiltrating it. For this reason, it is necessary to encrypt all your data hosted in the cloud; whether you are running a business or simply suing it for personal use, it is paramount to count on this first line of defense.

So what encryption is available? What are the most secure cloud storage providers?

What Is End-to-End Encryption (E2EE)?

End-to-end encryption (E2EE) is a communication mechanism through which only the users involved can read the messages. It means that your data is encrypted, i.e. rendered unreadable, before, during, and on arrival at its destination.

The main objective is not to allow spyware, internet providers, telecommunications service providers, etc., to access your data and communications. This is possible since the entire flow of information is encrypted using keys these entities do not have access to; in theory, only you and, depending on the situation, your cloud storage provider will have access to them.

These end-to-end (sometimes called "point-to-point") encryption systems have a robust cryptographic design. It is extremely difficult to break this cryptography by any surveillance system.

One of its great strengths is maintaining customer privacy. For example, a company that employs end-to-end encryption in its communications will not be able to hand over its customers' messages to the authorities.

So What Is Zero-Knowledge E2EE?

Zero-knowledge means that, in this case, the cloud company will not have access to your encryption key or data.

This is good and bad. First, it means that even if your data is handed to the authorities, in theory, they will not be able to read it because the cloud storage provider does not have the key to decrypt it. It's not that the company doesn't want to deliver the messages; it's that they can't because they don't have access to them.

The bad thing is that, if you lose your encryption key, your cloud provider will not be able to recover it for you.

What Are the Best E2EE Cloud Storage Providers?

Now that you know what E2EE is, here are our top 8 options.

1. IDrive

This E2EE cloud storage service resembles more of a back-up solution. This isn't a criticism of its functions but rather a note towards its hybrid approach to cloud storage. Its data servers are in the US, meaning they fall under US legislation, so despite IDrive's excellent privacy policy, they still fall under the Five Eyes network.

A unique feature of this E2EE cloud storage service is that, if needed, you can request a physical copy of your data. Once you pay for it, IDrive will mail you a physical hard drive to either back up or restore your data before sending it back.

2. Sync

Based in Canada (another Five Eyes nation), Sync is one of the best-priced cloud storage services. Additionally, Sync is a zero-knowledge E2EE storage service compliant with PIPEDA, GDPR, and HIPAA. It is worth noting that only paid plans offered the E2EE service.

Sync is also ideal for users who work with large files, as it does not have a limit on file size or transfer limits.

3. Icedrive

Icedrive is one of the best—and better priced—E2EE cloud storage services. Founded in 2019, its data servers are located in Wales in the UK. Unlike most encryption storage services, it does not use AES standard encryption but rather the lesser-known Twofish encryption algorithm.

There are three main drawbacks of Icedrive: data transfers will limit the uploads and downloads bandwidth performance; there are no two-factor authentication features; and there are very limited plans to choose from. These drawbacks are not severe since it's common for such a new company to expand services and capabilities slowly.

4. Internxt

Another very new E2EE cloud storage provider is Internxt. The company was founded in 2020 and launched in Spain. It currently promises its users that it will be the best privacy-protecting cloud on the market; it promises to do this by following a decentralized and distributed data storage policy model. It is also one of the few companies that utilize blockchain technology.

Unlike Icedrive, Internxy relies on the traditional AES encryption algorithms, which are open-source so that they can be improved or modified by users.

5. MEGA

Like Internxt, MEGA claims to be "the one company to promise to uphold privacy above all else". It's New Zealand-based and its unique feature is that it offers zero-knowledge E2EE for free and paid-for accounts (the latter are surprisingly inexpensive too). Very few companies provide E2EE cloud storage solutions for free.

6. pCloud

One of the most well-known zero-knowledge E2EE cloud storage providers is pCloud. It is based in Switzerland, which, alongside Germany, has some of the strongest privacy laws.

Its best feature is that it allows you to see all your files without downloading them. And it does not limit individual file sizes, which works great if you deal with a lot of huge files. The one drawback, and the reason pCloud is not at the top of the list, is that it only offers E2EE as an add-on.

It does have an excellent encryption algorithm; it uses RSA for users' private encryption keys and AES for personnel files and folder keys. The other significant advantages of pCloud are that it lets you choose data storage residency, there's no limit on file sizes, and it is an extremely user-friendly cloud.

7. Tresorit

Tresorit, pCloud's biggest competitor, is, funnily enough, also based in Switzerland. The main difference between the two is that Tresorit is slightly more business-oriented (meaning suitable for those looking for a cloud for multiple users).

Additionally, Tresorit is compliant with GDPR and HIPAA and fully adherent to Swiss privacy laws. As with pCloud, it allows users and enterprises to choose data residency. Its main drawback is that it is expensive since it primarily targets businesses.

8. SpiderOak

SpiderOak is similar to IDrive because it is more of a back-up solution than a traditional cloud storage service. Yet it also offers secure collaboration, communication features, syncing tools, and file-sharing. In simple terms, SpiderOak is conventional online storage (the old version of the cloud) that uses zero-knowledge encryption.

An Option for Every Need

There are E2EE cloud storage services for every need. These can be free ones, business ones, or EU-hosted ones. You'll probably prefer zero-knowledge providers though. Now that you know the best secure cloud storage services, you can go ahead and find one on the market to fit your needs better.