This guide should be good for most major distros out there but I have only tested it so far in centos 6. Sadly, there is a strange error message I am getting when decrypting that I have yet to discover how to fix, if anyone knows anything about it feel free to let me know, I will update if I find a workaround:
Create a file
touch foo
open the file
nano foo
write example text, I used
I’m on an encrypted system now.
Close the file and get ready to generate your key, but first verify that you have gpg installed
which gpg
It should show it in some place like /bin, if not install it. Assuming it was there type
gpg –gen-key
it asked me what type I wanted I choose 2, which is DSA only.
2
Now it asks me the key size, I choose the maximum of 3072
3072
Now, it asks me for the duration of time the key will be valid, I choose 6 months
6m
It asks me to confirm
Y
It asks me for my real name
John Q. Public
It asks me for my email address
it asks me to comment
temp key, used for one project
it gives me several options to correct it, everything looked fine so I selected O for okay
O
It asks me for a passphrase
Very LoNg password with 55 numbERS
It will now tell me to generate entropy, I used a floating point benchmark test and a lot of random typing to do this. After it is done, I test it on my file
gpg –c foo
it will prompt me for my passphrase twice and after I enter it, I check my directory
ls
and I see my encrypted file
foo.gpg
now, I want to decrypt it
gpg –o goo –d foo.gpg
I am asked my pass phrase
And I view my file
cat goo
now, I am assuming you are just going to use this key with a few people, so first we export our public key
gpg –armor –export > /home/myname/mypublickey
if you would open this file you will see the public key, which you can send out.
REFERENCES:
http://www.centos.org/docs/4/html/rhel-sbs-en-4/s1-gnupg-import.html
somelinuxdocs 