Note: This page is horribly out of
date.
You can find the current pages for the dm-crypt
project (the Linux kernel part) here:
https://gitlab.com/cryptsetup/cryptsetup/wikis/DMCrypt
and the project page for the command line tool
cryptsetup (with Linux Unified Key
Setup - LUKS) here: https://gitlab.com/cryptsetup/cryptsetup.
Old page:
Device-mapper is a new infrastructure in the Linux 2.6 kernel that provides
a generic way to create virtual layers of block devices that can do different
things on top of real block devices like striping, concatenation, mirroring,
snapshotting, etc... The device-mapper is used by the
LVM2 and
EVMS 2.x tools.
dm-crypt is such a device-mapper target that provides transparent encryption of
block devices using the new Linux 2.6 cryptoapi. The user can basically specify
one of the symmetric ciphers, a key (of any allowed size), an iv generation mode
and then the user can create a new block device in /dev. Writes to this device
will be encrypted and reads decrypted. You can mount your filesystem on it as usual.
But without the key you can't access your data.
It does basically the same as cryptoloop only that it's a much cleaner code and
better suits the need of a block device and has a more flexible configuration
interface. The on-disk format is also compatible. In the future you will be able
to specify other iv generation modes for enhanced security (you'll have to
reencrypt your filesystem though).
I've set up a Wiki.
There's a mailing list at .
If you want to subscribe, use the mailman
web interface or its
archive.
Gmane provides a NNTP interface and also a
web archive
for this mailing list.
There is support for dm-crypt in the latest official kernel
2.6.4
which you can find on kernel.org.
Please use the mirrors for downloads.
There is a HIGHMEM cryptoapi bug in kernels before 2.6.4-rc2, please
upgrade if you were using such a kernel.
The latest version of the native userspace setup tool is cryptsetup 0.1.
Clemens Fruhwirth is maintaining an
enhanced
version of cryptsetup with the LUKS extension that allows you to have an
on-disk block of metadata which is superior to the current mechanism and was
my long term plan anyway but I didn't find the time to implement that yet...
A mixtape in this era was defined by its features, and Akon utilized his A-list connections. The tape features prominent appearances from his Konvict Muzik roster, most notably T-Pain and Kardinall Offishall. The chemistry between Akon and T-Pain during this era is historical; they were the two kings of auto-tune and melody. Hearing them trade bars and hooks on a mixtape setting provides a
Akon has always possessed a unique vocal timbre—a high, slightly strained tenor that conveys a sense of urgency and pain. On this mixtape, that voice is pushed to the forefront, often layered over darker, more ominous beats than his usual radio fare. While The Koncrete is technically a mixtape, it flows with the cohesion of a concept album. It utilizes the classic mixtape format: exclusive freestyles, remixes of popular songs, and original tracks meant for the streets.
The project serves as a bridge between the "Konvicted" era and the incoming "Freedom" era. Listeners can hear Akon experimenting with the more electronic, dance-leaning sounds that would later define hits like "Right Now (Na Na Na)," but the subject matter remains rooted in the struggle, the hustle, and the pitfalls of the street life.
The core of the mixtape revolves around the "hustle." Tracks like the opener set the tone immediately. Akon’s strength has always been making criminality sound melodic. He sings about the risks of the drug trade and the pain of incarceration with a preacher’s conviction. On The Koncrete , he strips away some of the pop sheen, allowing the grit to show through.
In the mid-2000s, Akon was an inescapable force. He was the melodic genius who could seamlessly transition from a heartbroken R&B crooner on "Lonely" to a hardened street poet on "Locked Up." By 2007, he had cemented himself as a global superstar with the triple-platinum album Konvicted . However, amidst the chart-topping features and the glitz of mainstream success, Akon wanted to remind the world of his roots.
Hosted by the legendary DJ Drama (a titan of the mixtape game), the project carried the weight of the "Gangsta Grillz" cosign, instantly giving it legitimacy in the hip-hop community before the listener even pressed play. Musically, The Koncrete differs from Akon’s studio albums. While Konvicted and Freedom were polished products designed for radio rotation, The Koncrete was rawer. The production leaned heavier on trunk-rattling 808s, synthesized orchestration, and the unpolished energy that defines great mixtapes.
Released as a prelude to his third studio album, Freedom , this project serves as a fascinating time capsule. It captures an artist at the peak of his commercial power attempting to bridge the gap between radio-friendly pop and the grimy, mixtape culture that birthed him. While often overshadowed by his official studio discography, The Koncrete remains a fan-favorite essential for understanding the duality of Akon’s artistry. To appreciate The Koncrete , one must understand the landscape of 2007/2008. Hip-hop was undergoing a massive shift. The "ringtone rap" era was in full swing, but the streets were still ruled by gritty lyricism and mixtape heavyweights like Lil Wayne, Dipset, and G-Unit.
Akon had successfully launched his Konvict Muzik imprint, and his distinct sound—a blend of West African rhythms, R&B melodies, and hard-hitting hip-hop production—was the industry standard. However, critics often questioned his street credibility due to his pop crossover success. The Koncrete Mixtape was his answer. It was a statement that despite the platinum plaques, he was still "Konvicted" at heart.
The on-disk layouts used by the current 2.6 cryptoloop are supported by dm-crypt.
Cryptoloop also uses cryptoapi so the name of the ciphers are the same. Cryptoloop also
supports ECB and CBC mode. Use <cipher>-ecb and
<cipher>-plain accordingly with dm-crypt. If you didn't
explicitly specify either -ecb or -cbc before you don't need it now, the default plain
IV generation will be used. There will be additional (incompatible, but more secure) possibilites
in the future because the unhashed sector number as IV is too predictible.
You'll need to figure out how your passphrase was turned into a key to use for losetup.
There are several patches floating around doing things differently. But usually cryptsetup
will provide a working solution to recreate the same key from your passphrase.
If you want to migrate from 2.4 cryptoloop please take a look at Clemens Fruhwirth's
Cryptoloop
Migration Guide. He describes the differences between 2.4 and 2.6 cryptoapi (or basically
the bugs in 2.4 cryptoapi...). If you need to cut the key size you can use the -s
option instead of playing with dd.
(BTW: Clemens has a i586 optimized version of the aes and serpent cipher on his page,
about twice as fast as the kernel implementation.)
Why dm-crypt?
Originally it started as a fun project because I wanted to play with the new Linux 2.6 internals.
I got a lot of great help from the device-mapper guys at Sistina (now Redhat). Thank you very
much!
It turned out that this implementation worked great and is very clean compared to the hacked
loop device. The device-mapper core provides much better facilities to stack block devices.
dm-crypt uses mempools to assure we never run into out-of-memory deadlocks when allocating
buffers.
Also the device-mapper configuration interface provides much more flexibility than the losetup
ioctl. And you can create as many devices as you want with any names you want and combine them
with other dm targets. Online device resizing is also possible, e.g. if you use dm-crypt on top
of a logical volume. There might perhaps even be LVM or EVMS support for device encryption
in the future.
A mixtape in this era was defined by its features, and Akon utilized his A-list connections. The tape features prominent appearances from his Konvict Muzik roster, most notably T-Pain and Kardinall Offishall. The chemistry between Akon and T-Pain during this era is historical; they were the two kings of auto-tune and melody. Hearing them trade bars and hooks on a mixtape setting provides a
Akon has always possessed a unique vocal timbre—a high, slightly strained tenor that conveys a sense of urgency and pain. On this mixtape, that voice is pushed to the forefront, often layered over darker, more ominous beats than his usual radio fare. While The Koncrete is technically a mixtape, it flows with the cohesion of a concept album. It utilizes the classic mixtape format: exclusive freestyles, remixes of popular songs, and original tracks meant for the streets.
The project serves as a bridge between the "Konvicted" era and the incoming "Freedom" era. Listeners can hear Akon experimenting with the more electronic, dance-leaning sounds that would later define hits like "Right Now (Na Na Na)," but the subject matter remains rooted in the struggle, the hustle, and the pitfalls of the street life. akon the koncrete mixtape
The core of the mixtape revolves around the "hustle." Tracks like the opener set the tone immediately. Akon’s strength has always been making criminality sound melodic. He sings about the risks of the drug trade and the pain of incarceration with a preacher’s conviction. On The Koncrete , he strips away some of the pop sheen, allowing the grit to show through.
In the mid-2000s, Akon was an inescapable force. He was the melodic genius who could seamlessly transition from a heartbroken R&B crooner on "Lonely" to a hardened street poet on "Locked Up." By 2007, he had cemented himself as a global superstar with the triple-platinum album Konvicted . However, amidst the chart-topping features and the glitz of mainstream success, Akon wanted to remind the world of his roots. A mixtape in this era was defined by
Hosted by the legendary DJ Drama (a titan of the mixtape game), the project carried the weight of the "Gangsta Grillz" cosign, instantly giving it legitimacy in the hip-hop community before the listener even pressed play. Musically, The Koncrete differs from Akon’s studio albums. While Konvicted and Freedom were polished products designed for radio rotation, The Koncrete was rawer. The production leaned heavier on trunk-rattling 808s, synthesized orchestration, and the unpolished energy that defines great mixtapes.
Released as a prelude to his third studio album, Freedom , this project serves as a fascinating time capsule. It captures an artist at the peak of his commercial power attempting to bridge the gap between radio-friendly pop and the grimy, mixtape culture that birthed him. While often overshadowed by his official studio discography, The Koncrete remains a fan-favorite essential for understanding the duality of Akon’s artistry. To appreciate The Koncrete , one must understand the landscape of 2007/2008. Hip-hop was undergoing a massive shift. The "ringtone rap" era was in full swing, but the streets were still ruled by gritty lyricism and mixtape heavyweights like Lil Wayne, Dipset, and G-Unit. Hearing them trade bars and hooks on a
Akon had successfully launched his Konvict Muzik imprint, and his distinct sound—a blend of West African rhythms, R&B melodies, and hard-hitting hip-hop production—was the industry standard. However, critics often questioned his street credibility due to his pop crossover success. The Koncrete Mixtape was his answer. It was a statement that despite the platinum plaques, he was still "Konvicted" at heart.
Please contact the mailing list: dm-crypt@saout.de. Or in case there is a problem with the mailing list, me: .