I read about Cryptoloop and I wonder where can I use it?

I understand that:

Cryptoloop is a Linux kernel's disk encryption module that relies on the Crypto API, which is a cryptography framework introduced in version 2.5.45 of the Linux kernel mainline.[1] Cryptoloop was first introduced in the 2.5.x kernel series; its functionality was later incorporated into the device mapper, a generic framework used to map one block device onto another.

but i cannot see a function for it in my work or for example for a customer. Can anyone tell where I can apply this feature of the Linux kernel?

  • 3
    Stop worrying about it until you have a problem you need to solve. Commented Jun 28, 2018 at 6:31
  • @PhilipKendall I would like know how working crytoloop
    – simon
    Commented Jun 28, 2018 at 6:35
  • 2
    The phrasing of the question, as-is, is broad, IMHO. "How does it work" and "where can I use it" lead me to think "read the source code" and "lots of places".
    – Jeff Schaller
    Commented Jun 28, 2018 at 11:00

1 Answer 1


Don't use Cryptoloop!

Cryptoloop is an old mechanism for disk encryption in the Linux kernel. Disk encryption technology is typically used to prevent unauthorized access to data at rest, e.g., data stored on physical media such as hard disks. Disk encryption software, such as Cryptoloop, would encrypt all data written to disk.

Cryptoloop acts as a loop device driver that makes an underlying file or filesystem appear as a pseudo-device. The Cryptoloop driver encrypts data written to the pseudo-device on-the-fly before it is written to the underlying file or filesystem. It can thus be used to add encryption to any of the standard Linux filesystems without changing the filesystem code itself.

However, Cryptoloop was deprecated in Linux 2.6, is no longer maintained actively, and is vulnerable to watermarking attacks, a type of known-plaintext attack which make it possible to detect the presence of specially crafted files with a watermark bit pattern on encrypted file systems, even without access to the decryption keys.

The method of choice for disk encryption in modern Linux versions is dm-crypt and LUKS.

The Ubuntu installer can encrypt new ubuntu installations using dm-crypt and LUKS if the option is selected in the install wizard. Information on setting up full-disk encryption in Ubuntu manually can be found on the Ubuntu wiki.

  • +1 for the security recommendations. Commented Jun 28, 2018 at 9:15
  • OH THANK YOU, sorry if my question gone stupid but I dont expert in Linux/Unix
    – simon
    Commented Jun 28, 2018 at 19:47

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