Repository: Error NO PUBKEY

Saat

apt-get update

Error

Get:38 http://archive.ubuntu.com trusty/restricted Translation-en [3457 B]     
Get:39 http://archive.ubuntu.com trusty/universe Translation-en [4089 kB]      
Fetched 23.8 MB in 46s (514 kB/s)                                              
Reading package lists... Done
W: GPG error: http://archive.ubuntu.com trusty-updates InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 40976EAF437D05B5 NO_PUBKEY 3B4FE6ACC0B21F32 
W: GPG error: http://security.ubuntu.com trusty-security InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 40976EAF437D05B5 NO_PUBKEY 3B4FE6ACC0B21F32
W: GPG error: http://archive.canonical.com trusty Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 40976EAF437D05B5 NO_PUBKEY 3B4FE6ACC0B21F32
W: GPG error: http://archive.ubuntu.com trusty Release: The following signatures couldn't be verified because the  public key is not available: NO_PUBKEY 40976EAF437D05B5 NO_PUBKEY 3B4FE6ACC0B21F32

Untuk memperbaiki

sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 2EA8F35793D8809A

Ganti 2EA8F35793D8809A dengan key yang hilang, misalnya

sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 40976EAF437D05B5
sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 3B4FE6ACC0B21F32