encoding information in a way so that it can only be decoded if a secret is known; used to prevent exposure of data to other parties
Questions tagged [encryption]
860 questions
120
votes
13 answers
How to create SHA512 password hashes on command line
In Linux I can create a SHA1 password hash using sha1pass mypassword. Is there a similar command line tool which lets me create sha512 hashes? Same question for Bcrypt and PBKDF2.
student
- 17,875
- 31
- 103
- 169
72
votes
11 answers
SSH to decrypt encrypted LVM during headless server boot?
When I installed Ubuntu 10.04 and, now, 10.10, I was offered the option of enabling "encrypted LVM" for my hard drive.
After choosing that option, I am prompted for my password during boot to decrypt the LVM.
Now, I am thinking about setting up a…
hpy
- 4,517
- 8
- 53
- 73
67
votes
6 answers
SSH: How to disable weak ciphers?
Security team of my organization told us to disable weak ciphers due to they issue weak keys.
arcfour
arcfour128
arcfour256
But I tried looking for these ciphers in ssh_config and sshd_config file but found them commented.
grep arcfour…
Raja G
- 5,749
- 12
- 44
- 67
55
votes
6 answers
How to set password for pdf files?
I need to password protect my PDF file(s), because I am going to send them through email and I want anyone who would view my PDF file(s) to be prompted for a password.
How can I add a password to a PDF in Linux Mint 17.1?
David
- 711
- 2
- 7
- 12
45
votes
2 answers
Set default key in gpg for signing
I have created multiple keys using gpg.
Whenever I try to sign any file, gpg automatically uses the first one I have created. How to set default key for signing in gpg. I don't want to delete/revoke the other one yet.
Otherwise, how can I…
Aman Sharma
- 551
- 1
- 4
- 5
36
votes
4 answers
"No such file or directory" when generating a gpg key
I'm trying to generate a gpg key
$ gpg --full-gen-key
but eventurally I get an error
gpg: agent_genkey failed: No such file or directory
Key generation failed: No such file or directory
I'm on Arch Linux.
$ gpg --version
gpg (GnuPG)…
Meji
- 471
- 1
- 4
- 5
34
votes
3 answers
How to zip directory with encryption for file names?
Using command line, I know that I can encrypt a directory with the following command:
zip -er Directory.zip /path/to/directory
However, this does not encrypt the filenames themselves. If someone runs:
unzip Directory.zip
and repeatedly enters a…
Leo Galleguillos
- 463
- 1
- 4
- 7
34
votes
3 answers
How to encrypt messages/text with RSA & OpenSSL?
I have Alice's public key. I want to send Alice an RSA encrypted message.
How can I do it using the openssl command?
The message is:
Hi Alice! Please bring malacpörkölt for dinner!
LanceBaynes
- 39,295
- 97
- 250
- 349
30
votes
2 answers
Simplest way to password protect a directory and its contents without having to create new files?
I would like to password protect or encrypt a directory and all the files within it (for the whole directory tree below it). I do not want to bother the whole home directory, I want a specific directory with some files and folders in it. I would…
Vass
- 5,271
- 9
- 38
- 45
29
votes
4 answers
How to remove LUKS encryption?
I tried removing LUKS encryption on my home directory using the following command:
cryptsetup luksRemoveKey /dev/mapper/luks-3fd5-235-26-2625-2456f-4353fgdgd
But it gives me an error saying:
Device /dev/mapper/luks-3fd5-235-26-2625-2456f-4353fgdgd…
Question Overflow
- 4,568
- 19
- 57
- 84
29
votes
3 answers
How to decrypt hostnames of a crypted .ssh/known_hosts with a list of the hostnames?
I try to find a script to decrypt (unhash) the ssh hostnames in the known_hosts file by passing a list of the hostnamses.
So, to do exactly the reverse of:
ssh-keygen -H -f known_hosts
Or also, to do the same as this if the ssh config…
Xorax
- 515
- 1
- 5
- 9
27
votes
3 answers
OpenSSL 1.1.1b warning: Using -iter or -pbkdf2 would be better while decrypting a file encrypted using OpenSSL 1.1.0g
Today I got this warning issued by OpenSSL in Cygwin after updating some packages, I believe openssl was included:
*** WARNING : deprecated key derivation used.
Using -iter or -pbkdf2 would be better.
The OpenSSL version used in Cygwin…
Vlastimil Burián
- 27,586
- 56
- 179
- 309
27
votes
8 answers
Linux boot loaders supporting full disk encryption?
Are there any Linux boot loaders supporting full disk encryption (a la TrueCrypt). I know there was work towards adding encryption support to GRUB2, but this does not seem to be ready yet. Any other options?
(Note that I am really referring to full…
Grodriguez
- 906
- 2
- 11
- 31
27
votes
3 answers
Best practice to backup a LUKS encrypted device
What's the fastest method to backup and restore a luks encrypted device (e.g. a full encrypted usb-device to a image-file).
The usb-device can be decrypted/accessed. I'm looking for a solution to mount the backup image as a file (encryped). Can it…
mate64
- 1,469
- 5
- 16
- 24
26
votes
1 answer
Pre-encryption wipe, why?
I wanted to know why, before encrypting and installing itself on the drive , Kali :
wiped the whole drive
filled the drive with 0s
filled the drive with 1s
filled the drive with Random data
wiped the drive again
I know that Kali isn't meant to be…
Taz8du29
- 301
- 3
- 10