Like many people, I use dualboot, using Linux and Windows on my computer. I have one disk partition, which I want to be accessible from both Linux and Windows. On that shared data partition, I have some documents, photos, source code, GPG keys, and much more stuff I want to be encrypted.

Please note, that I’m not a security expert. This guide is probably imperfect from the security perspective! I am also not responsible, if you break your system or corrupt your data in any way!

I chose VeraCrypt, because it is multiplatform. On Windows, I installed VeraCrypt from the official website. On Linux, it is possible to use cryptsetup, so I used that instead of installing VeraCrypt.

Example setup

I’ve created a virtual machine for this example, using dualboot with Fedora 36 and Windows 11 (I use those systems on my real setup). The shared partition, which we will encrypt by VeraCrypt, is formatted as NTFS.

On Linux, to be able to use NTFS, I use NTFS-3G.

Disk layout looks like this:

disk /dev/sda is system disk - Fedora and Windows are installed there
- contains Linux and Windows root partitions, EFI partitions, and other “system” partitions
disk /dev/sdb is data disk - with the shared partition I want to encrypt
- it is just 1GB capacity for the demo
- partition /dev/sdb2 is the shared data partition I want to encrypt

Following screenshots show the disk layout using parted and lsblk on Linux and Disk management on Windows.

disk_layout_parted disk_layout_lsblk disk_layout_windows

Your disk layout might be completely different, of course. You might have just one disk, for example.

Encrypt the shared partition

I want to encrypt the partition in-place - without wiping the data on it. Sadly, this is possible with VeraCrypt only on Windows. This is why I will encrypt the partition from Windows

Windows

Run VeraCrypt with elevated privileges. Click on button Create volume. veracrypt_create_volume

Select Encrypt a non-system partition/drive. veracrypt_select_partition

Select VeraCrypt volume type. I selected Standard VeraCrypt volume. veracrypt_volume_type

Select partition you want to encrypt. veracrypt_select_partition

Select Encrypt partition in place. veracrypt_encrypt_in_place

Select encryption algorithm and hash algorithm. I selected the default, which is AES encryption algorithm and SHA-512 hash algorithm. veracrypt_algorithms

Create VeraCrypt volume password. The password should be strong, ideally generate one in a password manager. veracrypt_volume_password

Move by your mouse until you generate entropy enough. veracrypt_entropy

Select wipe mode. I selected None (fastest) for this demo. You should select a more secure option! The click on button Encrypt and wait until the partition is encrypted. Then click on button Finish. veracrypt_wipe_mode veracrypt_encrypt veracrypt_finish_encryption

When the encryption is finished, you can mount the encrypted partition. Select a free drive letter and click on button Auto-Mount Devices. Enter your password and mount the encrypted partition. veracrypt_mount

When you open a file manager, you should see one disk for the encrypted partition (E: in this case; will be impossible to open) and one disk for decrypted partition - after we mounted the encrypted partition in previous step (F: in this case). file_manager_mounted_partition

Linux

Open the encrypted partition by cryptsetup:

cryptsetup --type tcrypt --veracrypt open /dev/sdb2 data

That created a device on mapper: /dev/mapper/data.
Now it is possible to mount the decrypted partition:

mount -t ntfs -o windows_names,umask=0022 /dev/mapper/data /mnt/data

If you want to unmount the partition, simply use umount command:

umount /mnt/data

And optionally close the decrypted partition.

cryptsetup close data

linux_mount_veracrypt_partition_with_cryptsetup

Conclusion

And that’s it. Simple, right?
You can of course use different filesystem (you don’t have much of a choice, as Windows doesn’t support many filesystems).
Why did I choose cryptsetup over installing VeraCrypt on Linux? Because cryptsetup is native tools to Linux, it is already preinstalled on many distributions, and it works just fine.

VeraCrypt encrypted partition shared between Linux and Windows

Example setup

Encrypt the shared partition

Windows

Linux

Conclusion

Links