JustPaste.it - Share Text & Images the Easy Way

To set up an encrypted file on Linux that can be mounted and accessed like a hard drive, you can use LUKS (Linux Unified Key Setup) to create an encrypted container within a file, format it with a filesystem, and then mount it. This effectively creates a virtual encrypted disk that behaves like a regular storage device.

Here's a step-by-step guide:

1. Create an Empty File:

First, create an empty file with a desired size. This file will act as the container for your encrypted volume.
Use the fallocate command to create a sparse file (a file that only takes up space on disk as it's written to):

Code

    fallocate -l 10G encrypted_volume.img

This command creates a file named encrypted_volume.img with a size of 10 Gigabytes.

2. Initialize the LUKS Container:

Use cryptsetup luksFormat to initialize the LUKS container within the file:

Code

    cryptsetup luksFormat encrypted_volume.img

You will be prompted to enter a strong passphrase, which is essential for accessing the encrypted data.

3. Open the LUKS Container:

Open the LUKS container to create a device mapper entry (a virtual device):

Code

    cryptsetup luksOpen encrypted_volume.img encrypted_volume

Replace encrypted_volume.img with the actual filename and encrypted_volume with your desired name for the device mapper entry. You'll be prompted for the passphrase you set in the previous step.

4. Create a Filesystem:

Now, create a filesystem (e.g., ext4) on the opened LUKS device:

Code

    mkfs.ext4 /dev/mapper/encrypted_volume

Replace /dev/mapper/encrypted_volume with the actual device mapper path.

5. Create a Mount Point:

Create a directory where you will mount the encrypted volume:

Code

    mkdir /mnt/encrypted_volume

You can choose any suitable mount point.

6. Mount the Filesystem:

Mount the filesystem.

Code

    mount /dev/mapper/encrypted_volume /mnt/encrypted_volume

Now you can access the encrypted volume like a regular directory.

7. Accessing the Encrypted Volume:

To access your encrypted volume, you'll need to open the LUKS container and mount it each time:

Code

    cryptsetup luksOpen encrypted_volume.img encrypted_volume
    mount /dev/mapper/encrypted_volume /mnt/encrypted_volume

After you're finished using the encrypted volume, unmount it and close the LUKS container:

Code

    umount /mnt/encrypted_volume
    cryptsetup luksClose encrypted_volume

Key Considerations:

Security:

Use a strong passphrase and consider storing it securely, as losing it means losing access to your data.
Performance:

Encryption can introduce a slight performance overhead, but it's generally negligible for most uses.
Backups:

Always back up your data, especially if it's sensitive, as encryption doesn't protect against data loss due to hardware failure.
Alternatives:

While LUKS is a popular choice, other tools like VeraCrypt [NOTE: This website messes up this Google link] can also be used for creating encrypted containers.