Keeping the digital datas are the major concern now a days. So try to develop a safe and secure platform for storing the data. It will help the customers to avoid creating email IDs like gmail to use Google drive.

I use Linux. I feel safe to store my data offline. But there is no cloud drive to trust for privacy and security. Please bring this soon and for free users too. Thanks!

I would also like to see a Cloud drive service from Protonmail. Right now I'm using pCloud and very happy with it. Their approach to desktop sync is excellent, as you can set it up as a virtual drive, therefore the drive is gone when you turn off or restart your PC, which gives me peace of mind in case my PC is stolen.
They also have an encryption add-on.
Here's a link for a free trial if anyone's interested:
https://www.pcloud.com/welcome-to-pcloud/?discountcode=RbdDbTwE0FYQ3hvq8OJ9UHZV

Without going full blast like Tresorit, I think there is room for useful additions, especially if they are tightly integrated - I like what Fastmail has been doing: having Notes, for quick reference, and a file system which can be accessed by FTP or Web addresses (with or without password security).
What Fastmail lacks tho is a way to edit *internally* documents kept on these files or notes (without necessarily having too many Word/ Excel bells and whistles).
What is important is to have critical information secure and easily available within Protonmail

This idea crossed my mind, too. But I think ProtonBox would be a better name, even though it's not quite as self-explanantory as ProtonDrive. ProtonBox has assonance. ProtonDrive sounds kind of like the name of some fundraiser.

OF COURSE FILES HOSTED BY SERVERS LOCATED IN SWITZERLAND

yes all for it and in as protonmail is amazing and secure and would feel a lot better than any other service out right now

I like this idea a lot, but I think to be able to start this, we would have to pay much more to ProtonMail company, so it can host much more Gb of our data....
Right now even the free mailbox storage is too small for me to fully switch to PM.

It would be amazing if you use Collabora Office !!!!

It would be amazing if you host a nextcloud encrypted systema with share and collaborating office suite like Google Docs. It could use the Free and OpenSouce Collabora Office (Its is LibreOffice on-line).

Some Nextcloud service already offer Collabora Office, but no one is swiss based and have seriously encrypt.

You ProtonMail guys could use the Collabora Office, its open souce and based on LibreOffice. It would be amazing and would beat services like GoogleDocs

Tresorit+Protonmail is the combo.
Both are secure, private, easy to use, and under Swiss legislation.

Personnally, it's Tresorit which first convinced me to leave all those US-based companies (Google, Dropbox, Doodle...), after leaving Spideroak (USA legislation) and CNRS-hosted-owncloud that I could use for free (after a known bug reversed one day of work).

So integrate with Tresorit, partner with them, even buy them ultimately, but focus on what's missing to users, not on what already exists.

This is already provided by other services, so I dont see rhe point. I use Tresorit, which works great. Please focus on things that do not exist. Better integrate with existing private/secure services, and/or do a commercial partnership with them, or buy them if you have big ambitions.

Only if integrated with Protonmail the same way Yandex.disk and Yandex email work, where you can save attachments, etc.

Add geens.com to the list of similar services

I'm all for it.
I'm curious to hear opinions on nCryptedCloud, which I currently use. Any better recommendations?

As a couple of others have pointed out, there are several products that have been doing this for years. SpiderOak & Tresorit offer encrypted zero knowledge storage.
An easy to set up solution for keeping your files current on all of your devices is Syncthing. It is a peer to peer sync instead of a cloud, but it is free (FOSS), encrypted transfer, fast, and the only limit on data is your physical storage space.
I don't see what ProtonDrive would add that is unique, and it would be behind its competition.

If the offered a hosting of nextcloud with apps that i can add i might be interested. But if their own service probably not be interested.

Just use Owncloud, NextCloud or similar hosted from a NAS you run at home. You're in control and have the option of not opening it up to the web.

I've been running this succesfully on FreeNAS for 8 months and have had no issues.

https://owncloud.org/
https://nextcloud.com/

Wow! This really exploded in votes!

Anyway, @Anonymous, I think that it's different for ProtonMail since ProtonMail already offers an email service. Since they already have the technology to encrypt emails, it would probably be trivial to create an encrypted ProtonDrive that shares storage with ProtonMail.

As for the competition, I think the users of ProtonDrive will primarily be ProtonMail users and ProtonDrive will attract more users for both ProtonMail and ProtonDrive.

And I don't see how ProtonDrive would open ProtonMail up to more hacks. Isn't ProtonDrive just as secure as ProtonMail?

Overall, it seems like a pretty good idea to me! :)