yum install GPG NOKEY Error

YUM Error : GPG ,  V3 DSA signature , NOKEY

Many times we receive GPG  or  V3 DSA signature "NOKEY" Error while Installing packages in CentOS Linux by using yum.

yum install GPG NOKEY Error 

Error Example when installing a package that requires a Public Key:

Tested and resolve in :
OS: - CentOS release 4.8  (Solution will work on all version of CentOS)

warning: rpmts_HdrFromFdno: V3 DSA signature: NOKEY, key ID 443e1821
Public key for httpd-2.0.52-41.ent.4.centos4.x86_64.rpm is not installed

Install a public key using the the install disk, example CentOS:

(1) Insert CentOS Install DVD and cd to it.
# cd /media/CentOS-X-version

(2) List contents :  
#  ls
CentOS              GPL      images    NOTES                  repodata     RPM-GPG-KEY-centos4
centosdocs-man.css  headers  isolinux  RELEASE-NOTES-en.html  RPM-GPG-KEY  yumgroups.xml

(2) Run the command:
# rpm  --import *GPG* RPM-GPG-KEY-xxxxx (look for a RPM-GPG-KEY file in the install Media).

This will import the public keys for the yum installation.

Alternatively you can install the package without GPG Key check:

# yum install (package-name) --nogpgcheck