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74 votes
Accepted

Aren't keyfiles defeating the purpose of encryption?

If decryption only relies on the keyfile and this keyfile is readily available, there is indeed no significant security benefit in your setup. What you can do though is store the keyfile on a ...
Demento's user avatar
  • 7,495
57 votes
Accepted

Is LUKS still an effective option for consumer FDE considering Elcomsoft can break it?

No, Elcomsoft cannot break LUKS or Veracrypt. What they do is to guess the password. Any password-based encryption mechanism can be broken by guessing the password: this is not a flaw in the ...
Gilles 'SO- stop being evil''s user avatar
21 votes

Is LUKS still an effective option for consumer FDE considering Elcomsoft can break it?

While LUKS offers strong protection against brute force attacks by using thousands of iterations of a hash function during key derivation, we have significant advances in password recovery attacks ...
vidarlo's user avatar
  • 16.6k
15 votes

Does LUKS protect the filesystem integrity?

LUKS formatted with --integrity <algorithm> option will provide integrity protection for the encrypted volume. For that to work, --type luks2 must be used when formatting the device (opening of ...
Hubert Kario's user avatar
  • 3,808
14 votes

What does LUKS header contain?

For your information, I can't answer "Authoritatively" because I am not the author/contributor of LUKS/cryptsetup/dmcrypt but a user. But my answers are following, What does LUKS header ...
arif's user avatar
  • 1,156
12 votes

Aren't keyfiles defeating the purpose of encryption?

While Demento's answer is fine, I'd also present another user case I'm personally using: I have full disk encryption set up — using LUKS on a Linux-based box, and the scheme is implemented as follows: ...
kostix's user avatar
  • 221
11 votes

For LUKS: The most preferable and safest cipher?

Most preferable cipher is aes-xts-plain64 and it is used distro wide (RedHat, CentOS, Oracle Linux, Ubuntu) by default. Most of the people use AES because lots of the appliance, application support ...
arif's user avatar
  • 1,156
8 votes

access to mounted luks partition by non-root user

TLDR: Mount the filesystem in the user's home directory. This is not specific to luks since it applies to mounting in general. I have not tested with ext4 but I don't see a reason why it will be ...
stuffy's user avatar
  • 166
8 votes

LUKS2 dm-integrity

The dm-integrity authenticated encryption support for block devices is part of the Linux kernel since version 4.12. If it's enabled in your kernel then it should be automatically loaded, when needed. ...
maxschlepzig's user avatar
7 votes
Accepted

How to crack encrypted disk (crypto-LUKS) in an efficient way?

It depends what kind of encryption/format you have. Currently, there are many formats which cryptsetup support. Basically, the most popular are LUKS1 and LUKS2. You can check what kind of format you ...
kost's user avatar
  • 86
7 votes

access to mounted luks partition by non-root user

For future readers: Freshly formatted filesystem's root has usually rights of rwxr-xr-x and indeed is writable by root only. On the first mount, depending on the future use of this partition - ...
Pawel Kraszewski's user avatar
6 votes

Is LUKS effective?

If you don't select overwrite empty disk space option with LUKS, it is quick and not quite as secure. You are comparing LUKS's quick, less secure usage with Bitlocker's secure usage. If you selected ...
ferit's user avatar
  • 499
6 votes
Accepted

LUKS2 on-disk format specifications

Update: A full specification PDF for version 1.0.0 of the LUKS2 on-disk format can now be found in docs/on-disk-format-luks2.pdf. (It's a permalink, so check the master for updated versions.) It's in ...
Arminius's user avatar
  • 45k
6 votes

Is it possible to LUKS require both password and key file?

LUKS does not support requiring both a keyfile and a passphrase to decrypt. The encrypted volume can be decrypted as long as you provide satisfactory credentials to any one of the configured keyslots. ...
forest's user avatar
  • 67k
5 votes

Luks+Sleep: Login screen security?

Assuming all relevant SysRq features are disabled when the lock screen is active (SAK, sending SIGTERM or SIGKILL to all processes, triggering the OOM killer as you mentioned, etc), and assuming ...
forest's user avatar
  • 67k
5 votes
Accepted

Does full disk encryption offer mitigation in the case of the firmware of an SSD being compromised?

Partially. Full disk encryption, when done through software (e.g. LUKS), means that a compromised storage device will only ever see encrypted data, never decrypted data. It will never have access to ...
forest's user avatar
  • 67k
5 votes
Accepted

How difficult is it to decrypt a disk encrypted with luksOpen?

I'm wondering how difficult is it to decrypt this disk using bruteforce password guessing? It's not difficult, but it's time consuming. You only need the LUKS header and a lot of processing power. ...
ThoriumBR's user avatar
  • 54.6k
4 votes
Accepted

How can AES-CBC be used for LUKS encryption, when the ciphertext is not static?

This is actually a quite tricky problem with no perfect solution. If the file system was one were data is written only once and written entirely sequential, a single CBC encryption all the way from ...
kasperd's user avatar
  • 5,472
4 votes

Is LUKS effective?

If you do not overwrite the partition's free space, it's possible for an attacker to do two things: Scan the partition and view unencrypted data in places where you haven't written yet. Compare ...
LawrenceC's user avatar
  • 234
4 votes
Accepted

Limit of 256 bit drive encryption? 512 needed for large drives?

AES is a block cipher. Wikipedia says: The winner of the AES contest, Rijndael, supports block and key sizes of 128, 192, and 256 bits, but in AES the block size is always 128 bits. The extra block ...
Out of Band's user avatar
  • 9,283
4 votes

Can government authorities retrieve data from LUKS volume when it's accessed while turned on?

Absolutely. LUKS (and other disk encryption utilities) only provide data-at-rest security. That is, the only way to access the raw data itself when the system is powered off is by knowing the ...
forest's user avatar
  • 67k
4 votes

Should I upgrade old volumes to new cryptsetup encryption mode?

There is no security advantage to AES-XTS over AES-CBC-ESSIV—in fact, in the standard threat model for disk encryption (an adversary can read multiple snapshots of a disk, e.g. because of bad sectors ...
Squeamish Ossifrage's user avatar
4 votes

LVM on LUKS implementation

Unfortunately you are mistaken on several key points. LVM on LUKS is the only secure option for encrypting a Linux/Ubuntu USB system. There are other options, such as VeraCrypt, or using dm-crypt ...
AndrolGenhald's user avatar
4 votes
Accepted

What is a LUKS cipher-name "@"?

The cipher-name in your example is not '@'. The field you're looking at is actually the hdr_size field. The mistake you've made is trying to decode a LUKS2 container with LUKS1 encoding. In the table ...
Michael Altfield's user avatar
4 votes
Accepted

Can I secure the bootloader without a TPM?

Well, you could keep your bootloader on an external device and set your computer to boot from that device, but that would not protect from other forms of tampering such as a backdoor BIOS. Such a ...
forest's user avatar
  • 67k
4 votes

Recovering LUKS Encrypted Data

Downgrading your disk encryption backend to a vulnerable version doesn't help you with the data which is already encrypted. There would have to be a vulnerability in the version you used when you ...
Ja1024's user avatar
  • 11.4k
3 votes

Does mounting a LUKS partition authenticate it?

can they create a new encryption key and encrypt it so that the original passphrases can decrypt it? I don't see how that would be possible. As you already know, Luks works by generating a random "...
Out of Band's user avatar
  • 9,283
3 votes

How to crack encrypted disk (crypto-LUKS) in an efficient way?

There is a program that someone developed that is supposed to be able to crack LUKS passwords by utilizing a GPU, but I don't remember what the name of it was at the moment. I'll try to dig it up. ...
Elppa's user avatar
  • 31

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