There is no public key available for the following key IDs

when trying to apt-get update i got this error message :- W: There is no public key available for the following key IDs xxxxxxxxxxxx this problem was caused by change of gpg key used by ftpmaster on Debian official repository servers. Google gave me some information and I found some fix which works fine for me: error : W: There is no public key available for the following key IDs: 9AA38DCD5512345678 W: GPG error: http://ftp.us.debian.org etch Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 9AA38DCD5512345678 W: You may want to run apt-get update to correct these problems DO! find out invalid key. its 8 digits string from the right in my case my key id is 12345678 check the key id with #apt-key list find out if its there on not. the format should be xxxxx/our-key if you found one then #apt-get update if not? #gpg -a --export (error keyid here) | sudo apt-key add - #apt-key update #apt-key list then try to apt-get update again its work for me..

wak dogel