on running sudo apt-get

it gives error:

Hit http://in.archive.ubuntu.com lucid Release.gpg
Get:1 http://ppa.launchpad.net lucid Release.gpg [316B]
Hit http://packages.ros.org lucid Release.gpg
Get:2 http://security.ubuntu.com lucid-security Release.gpg [198B]
Ign http://in.archive.ubuntu.com/ubuntu/ lucid/main Translation-enIN
Ign http://ppa.launchpad.net/plushuang-tw/uget-stable/ubuntu/ lucid/main Translation-enIN Ign http://security.ubuntu.com/ubuntu/ lucid-security/main Translation-enIN Ign http://packages.ros.org/ros/ubuntu/ lucid/main Translation-enIN Ign http://in.archive.ubuntu.com/ubuntu/ lucid/restricted Translation-enIN Get:3 http://ppa.launchpad.net lucid Release [14.0kB]
Ign http://ppa.launchpad.net lucid Release
Ign http://security.ubuntu.com/ubuntu/ lucid-security/restricted Translation-enIN
Hit http://packages.ros.org lucid Release
Ign http://in.archive.ubuntu.com/ubuntu/ lucid/universe Translation-enIN
Hit http://ppa.launchpad.net lucid/main Packages
Ign http://security.ubuntu.com/ubuntu/ lucid-security/universe Translation-enIN Ign http://packages.ros.org lucid/main Packages
Ign http://in.archive.ubuntu.com/ubuntu/ lucid/multiverse Translation-enIN Ign http://security.ubuntu.com/ubuntu/ lucid-security/multiverse Translation-enIN Ign http://packages.ros.org lucid/main Packages Get:4 http://in.archive.ubuntu.com lucid-updates Release.gpg [198B] Get:5 http://security.ubuntu.com lucid-security Release [57.3kB]
Hit http://packages.ros.org lucid/main Packages
Ign http://in.archive.ubuntu.com/ubuntu/ lucid-updates/main Translation-enIN Ign http://in.archive.ubuntu.com/ubuntu/ lucid-updates/restricted Translation-enIN Ign http://in.archive.ubuntu.com/ubuntu/ lucid-updates/universe Translation-enIN
Ign http://in.archive.ubuntu.com/ubuntu/ lucid-updates/multiverse Translation-enIN
Hit http://in.archive.ubuntu.com lucid Release
Get:6 http://security.ubuntu.com lucid-security/main Packages [451kB]
Get:7 http://in.archive.ubuntu.com lucid-updates Release [58.3kB]
Hit http://in.archive.ubuntu.com lucid/main Packages
Hit http://in.archive.ubuntu.com lucid/restricted Packages
Hit http://in.archive.ubuntu.com lucid/main Sources
Hit http://in.archive.ubuntu.com lucid/restricted Sources
Hit http://in.archive.ubuntu.com lucid/universe Packages
Hit http://in.archive.ubuntu.com lucid/universe Sources
Hit http://in.archive.ubuntu.com lucid/multiverse Packages
Hit http://in.archive.ubuntu.com lucid/multiverse Sources
Get:8 http://in.archive.ubuntu.com lucid-updates/main Packages [645kB]
Get:9 http://security.ubuntu.com lucid-security/restricted Packages [2,867B]
Get:10 http://security.ubuntu.com lucid-security/main Sources [130kB]
Get:11 http://in.archive.ubuntu.com lucid-updates/restricted Packages [4,630B]
Get:12 http://in.archive.ubuntu.com lucid-updates/main Sources [228kB]
Get:13 http://security.ubuntu.com lucid-security/restricted Sources [1,267B]
Get:14 http://security.ubuntu.com lucid-security/universe Packages [135kB]
Get:15 http://security.ubuntu.com lucid-security/universe Sources [42.0kB]
Get:16 http://security.ubuntu.com lucid-security/multiverse Packages [5,353B]
Get:17 http://security.ubuntu.com lucid-security/multiverse Sources [2,321B]
Get:18 http://in.archive.ubuntu.com lucid-updates/restricted Sources [2,196B]
Get:19 http://in.archive.ubuntu.com lucid-updates/universe Packages [277kB]
Get:20 http://in.archive.ubuntu.com lucid-updates/universe Sources [103kB]
Get:21 http://in.archive.ubuntu.com lucid-updates/multiverse Packages [11.5kB]
Get:22 http://in.archive.ubuntu.com lucid-updates/multiverse Sources [5,821B]
Fetched 2,165kB in 1min 37s (22.2kB/s)
Reading package lists... Done W: GPG error: http://ppa.launchpad.net lucid Release: The following signatures couldn't be verified because the public key is not available: NOPUBKEY 8BE3EAB5EBE14A20 kushagra@kushagra:~/rosworkspace/rosjava_core$ gpg --keyserver subkeys.pgp.net --recv 8BE3EAB5EBE14A20

ON RUNNING gpg --keyserver subkeys.pgp.net --recv 8BE3EAB5EBE14A20

IT GIVES ERROR :

gpg: requesting key EBE14A20 from hkp server subkeys.pgp.net gpgkeys: key 8BE3EAB5EBE14A20 not found on keyserver gpg: no valid OpenPGP data found. gpg: Total number processed: 0

PLEASE HELP :(:(