Large-scale data breaches are becoming more and more common, with businesses faced with the disruptive loss of sensitive, commercial data. We’re not immune at home, either, with ransomware and phishing attacks putting our data at risk. When we store our information in the cloud, we want to be sure that no one will be able to access it without our permission.
That’s why it’s important to find the most secure cloud storage for your data. Thankfully, there are a number of cloud storage services out there who have made it their mission to offer cloud storage with strong security at reasonable prices. We’ve created a shortlist of six of the best and most secure cloud storage providers for personal and business use.
What Is the Most Secure Cloud Storage?
No suspense needed — the most secure cloud storage provider on our list is Sync.com. It offers zero-knowledge encryption as standard, even as an option for shared files. For our other top cloud storage providers for security, take a look at our shortlist below.
pCloud makes a close second, despite requiring an add-on to provide zero-knowledge protection. We’re big fans of both Sync.com and pCloud for secure cloud storage, but each of our providers offers something different, depending on your needs. Let’s take a closer look at each provider.
Sync.com is one of our favorite cloud storage services, and the level of security it offers plays a big part in why. You can learn more about its other features in our Sync.com review, but we’ll be focusing on security here.
For the best security for your files, you need a cloud storage service that offers zero-knowledge encryption. This means that your provider does not store a copy of your encryption key. Without the key, the company cannot access your files — period. If the servers were accessed illegally or a government issued a warrant, your information would still be inaccessible to anyone but you.
Sync.com offers zero-knowledge security on all of its plans, starting with a free account that includes 5GB of cloud storage, which we consider to be one of the most secure free cloud storage options.
If you’re looking to store only a few files, but want them to be as secure as possible, then this free storage plan is the perfect fit. It’s one of the reasons that Sync.com topped our list of the best zero-knowledge cloud services.
The security features that Sync.com offers don’t stop at zero knowledge. The TLS protocol is used to protect your data in transit, while data at rest is secured with industry-standard AES 256-bit encryption. The encryption keys themselves are protected with RSA 2048-bit encryption.
Sync.com also offers two-factor authentication, although it isn’t enabled by default, so it’s something we’d recommend you turn on immediately.
Personal accounts start from as little as $5 per month for 200GB of storage or just $8 per month for 2TB. Business accounts start from $5 per month for each user, with 1TB of storage space each. All of these plans are billed annually — there’s no option to pay monthly.
With such a strong focus on security, the payoffs apply to privacy, too. Everything you store on Sync.com has data residency in Canada, one of the best nations for data privacy.
This means that your information is kept safe from any attempts to access it through the USA Patriot Act. It falls under the Canadian Personal Information Protection and Electronic Documents Act (PIPEDA) instead, which requires businesses to seek an individual’s consent when they disclose personal information.
In fact, Sync.com’s privacy and security are so good that it is HIPAA compliant. This means that businesses that need to store sensitive personal health information can use Sync.com’s cloud storage services and still remain compliant with the regulations. Only providers with a proven track record of strong security and privacy meet these standards.
If you’re concerned about sharing private information with other people, then Sync.com has you covered there, too. You can choose to send your links with SSL encryption in transit, but if you enable enhanced privacy, then your links will also have end-to-end encryption.
One issue with this level of privacy for links is that it is not fully compatible with some browsers, including Safari, the default browser for most iPhone users.
- Zero knowledge
- Encryption offered on free plans
- Canadian data residency
- No monthly payment plan
- Encrypted links don’t work with Safari mobile
- No Linux support
If you’ve read some of our other guides, you’ll know that pCloud regularly features near or at the top of many of our lists. It’s a very good all-rounder, and we have no hesitation recommending it for a wide range of uses. You can read a broader examination of its merits in our pCloud review.
We raved about Sync.com’s zero-knowledge protection, but you may be surprised to find that pCloud doesn’t actually offer zero-knowledge as standard. If you want zero knowledge for your files and folders, you’ll need to pay for an add-on called pCloud Crypto, which costs $3.99 per month for an annual subscription.
With 2TB of storage costing $9.99 per month, pCloud Crypto could be a significant additional cost for consumers, which is something to consider if you’re on a budget.
We’re not fans of paying extra for security, but pCloud has benefits that shouldn’t be ignored. It allows you to store both encrypted and unencrypted files in the same account. If you’re only worried about protecting some of your more sensitive files, you can isolate these with much higher security than non-sensitive files, making your other files more accessible.
This is intended to overcome one of the major drawbacks of using zero-knowledge security — the server itself has no idea what type of files it is dealing with. This limits how much it can help you with your files. For instance, the server cannot transcode media files, preventing you from playing them in the cloud in most cases.
One of the most common issues is that you are unable to preview thumbnail images of encrypted cloud storage photos, which can be a real problem when you’re trying to deal with your photo collection. With pCloud Crypto, you can turn off zero-knowledge encryption for all of your photos or turn it on only for the ones that you don’t want any prying eyes to see.
When it comes to storing photos in the cloud, pCloud is a strong choice; it ranked highly in our list of the best online storage for photos.
Another very useful feature of pCloud Crypto is that you can lock your local files so that a password is required to open them. With some other providers, if someone has access to your desktop or laptop, they can go into your sync folder and see all of your decrypted files.
This feature offers greater protection if you use a shared computer or if you are unfortunate enough to have your laptop stolen. Read our full pCloud Crypto guide for more.
Additional pCloud Features
pCloud is a provider that puts its money where its mouth is when it comes to security. The pCloud Crypto Hacking Challenge — a six-month contest in which pCloud offered a reward of $100,000 to anyone who could hack through its client-side encryption — had nearly 3,000 participants. Not a single participant succeeded in breaching pCloud’s security measures.
Unlike some of the other providers on this list, pCloud also offers a Linux client, as well as Windows and macOS clients. If you’re a Linux user then you’ll be interested to learn that pCloud topped our list of the best cloud storage for Linux. There’s even an Adobe Lightroom add-on that allows you to save directly from the photo-editing software to your pCloud account.
As a Swiss-based company, pCloud is compliant with the EU’s GDPR regulations. Your files are stored on U.S. servers, however, so you may find your non-encrypted files could be accessed by law enforcement agents, should they seize the servers holding them.
- Different levels of file encryption
- Lockable local files
- Linux support
- Zero knowledge requires add-on
- pCloud Crypto doubles the price of some plans
- Files stored in the U.S.
With a name based on the German word for “safe” or “vault” (tresor), you’d expect Tresorit to be fairly high up on any list of the most secure cloud storage. Tresorit certainly lives up to its name, with security being its biggest selling point, although it has a lot of other useful features that you can read more about in our Tresorit review.
Like Sync.com, Tresorit offers zero-knowledge encryption on all of its plans, including its free account, which includes 3GB of storage. It uses the TLS protocol for data in transit to protect against man-in-the-middle attacks. Data at rest is protected using AES 256-bit encryption.
The way Tresorit works is a little bit different from most of the competition, as it helps you keep your information secure by compartmentalizing it. Instead of having one virtual folder to store your data, you can create individual parent folders called “tresors” that you can encrypt. Any local folder on your computer can be turned into a tresor.
If you create a new tresor, any files or folders uploaded into it will only be stored in the cloud, freeing up space on your hard drive. If you want the changes you make to local files to sync automatically, you can turn on this feature in Tresorit’s settings. Alternatively, you can drag and drop a local folder to Tresorit and it will sync across.
One bonus of using tresors is that they allow you to control what is shared with other people. You can share a link to any tresor — or to any folder or file held within one — and the recipients will be able to access those files but won’t be able to edit them unless you give permission.
The other option is to invite collaborators to a specific tresor. They will then be able to access the exact same files and folders, allowing them to add, edit or delete them. This is ideal for a group of people wanting to collaborate on the same files while allowing you to keep other tresors private.
Your collaborators will need Tresorit accounts to do this, but you can share with users who have a free Tresorit account, so the cost is minimal.
Other Tresorit Security Features
One drawback of zero knowledge is also its biggest benefit. If you lose your password and don’t have your encryption key, you can’t access your account and your files are lost forever.
Tresorit can’t reset your password and won’t be able to bypass the encryption. With this in mind, consider using a good password manager, like LastPass or Dashlane, to store your password or key.
Another optional feature you should consider enabling is two-factor authentication. This is usually in the form of a code generated on a specific device, such as your phone. Unless hackers have both your password and your phone, they won’t be able to access your account, offering another layer of security.
The biggest problem with Tresorit, compared to our top two providers, is the cost. You’ll need to pay $12.50 per month for just 200GB of cloud storage, and a huge $30 per month for 2TB. That’s more than three times the price of Sync.com for the same amount of storage.
If you’re after a business plan, there is currently a 50 percent discount available for businesses requiring 10 or more users, making it $15 for 1TB of storage per user per month.
- Zero knowledge
- Innovative system of tresors
- Two-factor authentication
- Can’t access shared tresors without signing up
Egnyte is one of the most secure cloud storage for business options, and it’s definitely worth a look if you need to store commercial files, especially as it came out on top overall in our list of the best enterprise file sync and share providers. If you’re a small business owner, we’d definitely recommend taking a look at our Egnyte review.
Egnyte doesn’t offer zero-knowledge protection out of the box, but if you want to take control of how your encryption key is stored, you’ll need to use Egnyte Key Management. This allows you to manage your own encryption keys, either yourself or via a third-party solution, such as Microsoft Azure Key Vault.
It should be noted that Egnyte Key Management is only available on Egnyte’s Enterprise plan, so it doesn’t come cheap.
The good news is that if the Enterprise plan is too much, there is another way to get the security of zero knowledge even if your provider doesn’t offer it. Encryption software allows you to encrypt your files before they’re uploaded into the cloud.
Third-party services, such as Boxcryptor, allow you to encrypt your files, no matter which provider you use. If you want to learn more, take a look at our Boxcryptor review.
Because Egnyte is aimed at the enterprise market, there aren’t any individual plans. If you want to use Egnyte for personal storage, then the Team plan has a minimum of a single user and costs $10 for 1TB of storage.
Egnyte Security Features
Despite the lack of zero knowledge, Egnyte still offers a lot of strong security features, especially the more “physical” protection your information might require. Its data centers have 24-hour surveillance, biometric access controls and are resistant to natural disasters, ensuring that your information is kept safely stored.
On a more technical level, Egnyte uses industry-standard AES 256-bit encryption for storing your data, and the TLS protocol to protect it during transit.
There is also an option to set up two-factor authentication so that your information is safe, even if your password is exposed. As the account administrator, you can also set minimum password strength requirements to ensure that none of your colleagues are trying to sign in with weak passwords.
Egnyte business plans also allow you to manage employee devices to give you greater control over your data security. You can set passcode locks so that users need to enter a four-digit code when they log in to Egnyte. It’s also possible to remotely wipe devices if they’re lost or stolen to avoid sensitive information falling into the wrong hands.
- Two-factor authentication
- Useful security options for business use
- Encryption key management on Enterprise plan
- No zero knowledge for most plans
- No published pricing for Enterprise plan
- No Linux support
MEGA used to offer a huge 50GB of cloud storage for free. That’s no longer the case, but you do gain a new user bonus of 35GB for the first 30 days, as well as other bonuses for referring users. As you can read in our MEGA review, its paid plans are definitely worth a look, too.
The company has a bit of a reputation, thanks to its infamous creator, Kim Dotcom, who is wanted by the U.S. to face copyright infringement charges. The company is now independent of his leadership and control, but it continues with his ethos, offering zero-knowledge security designed to prevent state agents from accessing your data at will.
MEGA recommends the use of a password manager so you don’t lose access to your information, and we’d recommend an option like 1Password to do the job. Unlike many zero-knowledge providers, MEGA does give you the option of saving a backup recovery key in case you lose your password.
The end-to-end encryption means that MEGA can’t reset your password for you, so this key will allow you to reset your password yourself. If you don’t handle this encryption key correctly, someone else may be able to reset your password and access your account, so you’ll need to think about storing it safely.
MEGA’s approach focuses on the weakest link to data security: the user. With that in mind, the site strongly recommends the use of two-factor authentication as well as encrypting your entire hard drive to keep data secure at the point of use.
MEGA’s data centers are in reasonably privacy-friendly locations, such as Luxembourg, Germany, Canada and New Zealand. However, none of these locations make our list of the countries with the best cloud privacy laws.
More importantly, none of your files are ever stored in or made available from the U.S., so they fall outside of the reach of legislation, such as the Patriot Act. The European locations mean that its pricing is in euros, but it works out to be about $11 per month for 2TB of cloud storage.
MEGA complies with European GDPR regulations designed to protect the data of EU citizens. The company takes things one step further and applies those same GDPR protections to all of its users, regardless of whether they reside in the EU or not.
There is also a vulnerability reward program that offers cash incentives to anyone that can find potential security issues.
- Zero knowledge as standard
- GDPR protections applied to all users
- Recovery key for lost passwords
- Free storage is time-limited
- Not the cheapest option
SpiderOak stands out compared to other options on this list as an online backup service, rather than a “true” cloud storage provider. However, it also offers file sharing and syncing, so it can be used as cloud storage, although you can only sync and share files that are part of your file backups.
Even so, if you’re looking for a backup service as well as cloud storage, then it’s definitely worth taking a look at our SpiderOak ONE review.
SpiderOak offers zero-knowledge encryption as standard. It uses AES 256-bit encryption for data at rest and TLS/SSL for all network traffic. Each file and folder is encrypted with a different key, as well as each version of your files. This allows SpiderOak to backup multiple versions of your files so you can revert back to an older copy if you need to.
However, this level of security doesn’t apply to files and folders that you’ve shared with other people. If you share a folder (which SpiderOak calls “sharerooms”), then the contents of that folder are no longer protected by zero knowledge. If you want strong security even for shared files, you’ll need to look at one of the other options on the list.
SpiderOak is available for Windows, Linux and macOS, rating highly on our list of the best cloud backup for Mac. There are also apps for iOS and Android available, but these will only grant you read-only access to your account, so you can’t upload or sync from a phone or tablet, which is a big disappointment. Surprisingly, there’s currently no two-factor authentication available.
SpiderOak certainly isn’t the cheapest option on our list. For $6 per month, you will only get 150GB of storage. For 2TB you’ll need to pay $14 per month. There’s also no free tier available, although there is a 21-day free trial if you want to try SpiderOak out.
The only information it collects is your login details, billing information and some device information, such as the amount of data stored on its service, as well as the date and time of access requests. According to SpiderOak, this information is never sold or shared with third parties other than to comply with legal requirements.
SpiderOak’s servers are based in the U.S., so your data is still subject to the Patriot Act. This means that SpiderOak could be compelled to hand over all your data to law enforcement, if required.
However, because SpiderOak uses zero knowledge, your data will be encrypted and will be unreadable without your password or encryption key. Even if SpiderOak wanted to decrypt it, it wouldn’t be possible (except for shared folders).
- Includes backup options
- Offers zero knowledge
- Lacks two-factor authentication
- No zero knowledge for shared folders
- More expensive than some providers
How We Picked Our Providers
As with all of our cloud storage reviews, we look at each provider to consider the strengths and weaknesses of each. We pick what we think are the best providers for each category, regardless of how we’ve rated them in other reviews.
Our aim is to provide you with the best advice possible. That’s why we’re happy to recommend SpiderOak, a backup product, in this list of cloud storage providers, due to its focus on security mixed in with good pricing. It’s also why pCloud and Sync.com make our list, with affordable plans, as well as good security and privacy measures on offer.
If you’re looking for the most secure cloud storage, our number-one pick is Sync.com. It offers zero-knowledge encryption out of the box, even for free users. Paid plans are very reasonably priced, so if you’ve got a lot of data to store, it’s not going to break the bank.
A close second is pCloud, which — despite requiring a paid add-on for encryption — has some unique features that make it a strong contender. These include the ability to decide which files and folders get the strongest encryption, allowing you to share other files with different users.
Tresorit, SpiderOak, Egnyte and MEGA all bring something different to the table, and any of them would do a great job of keeping your data secure in the cloud. Let us know your own thoughts and opinions on these secure cloud storage services in the comments below, and thanks for reading.