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Questions tagged [luks]

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LUKS (Linux Unified Key Setup) is a disk-encryption specification.

96 questions
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Best luks setup disk [duplicate]

I want to encrypt my disk but I want to know what is the best configuration, I currently use ths: cryptsetup -v --cipher serpent-xts-plain64 --key-size 512 --key-file=- --hash whirlpool --iter-time ...
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Is double encrypting with AES safe?

Is it safe to encrypt twice with AES, with any mode? Are any combinations of AES, e.g. AES with XTS and AES with CBC, or twice with AES and XTS, more unsafe than just having it encrypted once? I know ...
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LUKS mitigate brute force attacks even if salt parameter is know?

From What users should know about Full Disk Encryption based on LUKS In Linux world, LUKS implementations are based on cryptsetup and dm-crypt. In order to mitigate the problem of brute ...
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LUKS partition encryption vs. .vmdk level encryption

Because of data classification that is stored on one of our servers we need to make sure that it is protected while in transit and at rest. While the first can be addressed with proper TLS ...
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Is suspend-to-ram really a meaningful risk for Full Disk Encryption?

Ubuntu offers full disk encryption relying on luks. An often recurring area of criticism is the fact that Ubuntu disables hibernation by default while suspend-to-ram stores the private keys in the ram ...
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security of cryptsetup(8) luksRemoveKey, feasibility of extracting MasterSecretKey and using it later

I looked at https://crypto.stackexchange.com/a/24024 and it seems to me cryptsetup(8) luksRemoveKey is weak. The situation: I create new LUKS volume, copy stuff into it. I add a new pass phrase, and ...
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185 views

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

My goal is to be able easily destroy medium with key file in emergency situation and make system unbootable, even is potential advisor knows right password for the system. I'd store this key file in ...
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137 views

dm-crypt/LUKS: one-time password

I've setup arch using dm-crypt / luks, with a passphrase and a key, lost one of them will fail to login. But I feel I need more secure of passphrase, how to setup dm-crypt / luks that has one-time ...
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Can information somehow be secured from the host on a KVM guest?

With KVM guest systems so prevalent now, I was wondering if there is any merit in using LUKS encrypted storage, as the guest will usually be always on, so the information is always accessible ...
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Using command (dd if=/dev/mmcblk0p1 | sha1sum) while running from initramfs

I have an opensource airgapped raspberry pi project seen at the following link: www.privatekeyvault.com I have provided a method for installing LUKS full disk encryption seen at the following: https:/...
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Security/Privacy OS With Boot On Thumbdrive

I am looking for a security-centered Linux OS that allows you to take the /boot partition on a thumb-drive to alleviate concerns of an Evil Maid Attacks! What OS is it easy to remove the /boot ...
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4answers
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Are multiple encrypted containers with the same passphase containing the same files a cryptographic risk?

Situation as follows: Let's assume two (or more) containers, encrypted using the same passphrase. They will contain the same files. So their content is identical. However, the containers themselves ...
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Automatic fetch Luks keyfile over ssh and decrypt partition [closed]

I run a small computer with an encrypted data partition. So that I have as little effort as possible to decrypt the hard disk after a reboot (no extra ssh login, password input etc.), I thought about ...
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167 views

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

Suppose the firmware of an SSD or HDD has been compromised by rogue actors either through "interdiction" (interception) or via the internet. They are able to exfiltrate data and conduct surveillance ...
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176 views

How does default Debian boot drive encryption works?

When installing Debian, I chose an option to create Encrypted LVM (Logical Volume Management). So now, when I turn on my PC, it asks me for an encryption password. It looks ok, but how does it work? ...
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1answer
898 views

Use TPM2.0 to securely decrypt the hard drive in Linux — unattended

I already spent several days trying to figure out how to securely decrypt a hard drive on remote location using TPM2.0 in Linux. I'm no security expert and this is my first battle with TPM2.0. I ...
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399 views

Full disk encryption vs file based encryption

I need to protect a few hundred thousand files stored on a drive on a Linux server. I am thinking full disk encryption with file encryption on top would be the best option. Failing that, file based ...
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1answer
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Can government authorities retrieve data from LUKS volume when it's accessed while turned on? [duplicate]

I've heard that there are attacks that can get passwords out of RAM while turned on. If a server, CentOS 7.5 and LUKS enabled, it's tty1 locked, which is on a VMWare hypervisor that is locked with a ...
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Luks+Sleep: Login screen security?

Situation: A Desktop Linux (eg. Debian, Xfce desktop, Lightdm login) with LUKS-encrypted partitions (as far as possible, eg. Efi files are not encrypted of course). The computer is in sleep mode (not ...
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1answer
902 views

LUKS2 dm-integrity

I am using Debian 9.5, Linux Kernel 4.16, I would like to use the dm-integrity feature with cryptsetup. cryptsetup luksFormat --type luks2 <device> --cipher aes-gcm-random --integrity aead ...
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1answer
132 views

dmcryt_write process in TOP but no WRDSK indicated

I am using LUKS over RAID0. I have executed cryptsetup -v --cipher aes-xts-plain64 --key-size 512 --hash sha256 --iter-time 2000 --use-urandom --verify-passphrase luksFormat /dev/md0 Everything ...
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1answer
353 views

If a LUKS encrypted VM is put in saved state, will the master key be in clear on the host?

Let's assume the host is not encrypted, and all files on it are accessible. A VM with LUKS encryption is saved, meaning its memory is now residing as a regular file on the host, does that memory also ...
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1answer
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recommendation to change encrypted-drive passphrases

There are numerous recommendations for how frequently to change users' passphrases, and I think the most recent NIST recommendation is "no minimum time to change passwords" (I might be mis-quoting). ...
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240 views

Automatically Open LUKS Container on System Boot in a safe manner

I have a linux system running at a cloud provider where I created an encrypted container using LUKS to store personal data. The encrypted container is manually mounted at /srv; the rest of the ...
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1answer
693 views

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

I am building an encrypted NAS with 4 x 4TB hard drives and was wondering what the limit of 256 bit AES is when implemented via cryptsetup and luksFormat. As I understand it, the maximum plaintext ...
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1answer
1k views

LUKS2 on-disk format specifications

The LUKS1 format has been available for a long time, and the format specifications are easy to find. Recently, LUKS2 has been released, which features a number of important changes, such as AEAD and ...
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1answer
126 views

Wiping data properly in LUKS encrypted drive

Is it enough just to remove the header of LUKS device to wiping (unrecognizable) the data completely? Or it is recoverable (I don't want to recover though)? I need some safeguard to wiping my ...
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3answers
1k views

If I switch to LUKS on an SSD, have I just wiped it?

I have been using an SSD with no system-level encryption. If I now switch to full disk encryption using LUKS + LVM, do I effectively wipe the old data, or is it still hanging around until overwritten?
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How secure is my logged out but not shut down luks HD

I'am running a Ubuntu 16.04 on a luks encrypted disk. Normally when I leave my machine for some minutes, I always shut it down to be safe with the luks encryption. But I wonder, what the possible ...
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1answer
294 views

What’s the security risk when setting the Gnome keyring password to blank on an FED system with autologin?

My system disk is full encrypted with luks. My Ubuntu logs in automatically, because I am the only user. But I still need to unlock my Gnome Keyring and I wonder, if there is any sense for that. ...
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1answer
335 views

LUKS overwrite empty disk space question

I have a question about LUKS and the overwrite empty disk space option. I know what it does, and why people use it but I have a question about it. Forgive me if this question is dumb, it's just ...
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1answer
195 views

What information can be found about a LUKS-encrypted drive?

Let's say someone found a USB drive at their home and wants to try to figure out what it is (and they don't know the encryption phrase). What information could be determined about this encrypted drive,...
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1answer
455 views

Resetting LUKS password from CLI with the recovery key

I have a dd of a computer which has a LUKS-encrypted partition. I do not have the password but I do have a recovery key which would allow me to change the password through a GUI interface when the ...
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2answers
762 views

Why does LUKS use CBC?

I read that LUKS uses 256-bit AES with CBC by default. CBC, of course, has the disadvantages that if you change something in the plain text, you have to change everything that comes after it. In the ...
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3answers
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Security of different Filesystems

Are there any preferred filesystems that have some boni regarding security and confidentiality? Or does it really not matter if I, for example, encrypt a HDD with LUKS? As an example, I read that the ...
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1answer
255 views

cryptsetup luksHeaderBackup file smaller than Payload Offset?

I created test LUKs container in a file, the luksDump says MK bits: 256 Payload offset: 4096 implying that the header is 4096*512 = 2MiB but the file produced by cryptsetup ...
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1answer
280 views

Preventing LUKS key dump

Is it possible to prevent a root user (user space) from running dmsetup table --showkeys to dump the LUKS master key? I know of the TRESOR patch which essentially prevents the key from persisting in ...
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1answer
89 views

Does mounting a LUKS partition authenticate it?

Can I be sure that the (unencrypted) contents of my LUKS volume were not tampered with if it accepts my passhprase on an otherwise trusted system? In other words, can an attacker with access to my ...
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1answer
317 views

Access encrypted files (dm-crypt/LUKS) through web app

I'm a newbie to encryption issues and I'm trying to sort out a few questions. For a distributed application we need to deploy a server outside of our company with sensitives PDF files on it. That ...
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1answer
149 views

Mapping of encrypted to decrypted blocks in LUKS

Section 2.4 What is the difference between "plain" and LUKS format? of the cryptsetup Frequently Asked Questions says the primary advantage of plain dm-crypt (no LUKS) is: ...high resilience to ...
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477 views

Is deleting LUKS keys during operation a good way to protect my data?

Let's say Alice owns a server that stores highly sensitive data. Let's further assume the data is worth a lot, but losing all data is way less of a problem than having it read by attacker Mallet. To ...
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1answer
286 views

Is scrubbing a ssd drive effective in situations where you can't use the trim command?

I have a luks encrypted external usb ssd drive (Samsung T3) which is unable to use the trim command. This leaves me to search for a different way to securely erase the free space inside the encrypted ...
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3k views

Is LUKS effective?

I ask this because encrypting an hard drive using LUKS takes a few seconds while encrypting the same drive using Bitlocker takes several hours. Does that mean LUKS encryption is weaker?
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1answer
2k views

How does LUKS work? [closed]

I was just curious if someone had a high level overview of how a system like LUKS worked for full disk encryption, aka. how it stores keys and how those keys are verified, and if data is de-crypted by ...
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1answer
1k views

Differences between LUKS and Veracrypt

These two FDE solutions are similar, but I noticed different executions speed: specially mounting a device it seems that Veracrypt takes more time decrypting it. So I would like to compare it with ...
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2answers
597 views

Is wiping LUKS header needed?

So I previously had an encrypted install of Debian, and wanted to install a new distro with full system encryption again. Now I understand that you don't need to fill the disk with random data if you ...
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1answer
7k views

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

I had a disk encrypted by crypto-LUKS but forgotten password. I read a question posted here. LUKS HDD Encryption crack But before that I want to know if there's some free software I can use to ...
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1answer
2k views

Is using trim on a ssd with LVM LUKS safe?

I know that it can allow an attacker to know the filesystem and file size, but can it allow an attacker to decrypt any files?
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22k views

Right way to use the TPM for full disk encryption

I'm currently setting up a BitLocker equivalent using a TPM and LUKS. I've got the basics right and I'm able to measure the boot process and seal the FDE key using the TPM. Every time the sensitive ...
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1answer
1k views

Change LUKS encryption key (not passphrase) without dataloss

You can change the LUKS passphrase without dataloss, but can you also change the actual key? I reckon you would have to re-encrypt the whole disk, but that would be acceptable to me. Background We ...

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