how to get around this mess : GPG error: http://ftp.ports.debian.org/debian-ports unstable InRelease

[Dennis Clarke <dc@oetec.com>]

This has been happening for weeks with a simple apt-get update :

.
.
.
Reading package lists... Done
W: An error occurred during the signature verification. The repository 
is not updated and the previous index files will be used. GPG error: 
http://ftp.ports.debian.org/debian-ports unstable InRelease: The 
following signatures couldn't be verified because the public key is not 
available: NO_PUBKEY 06AED62430CB581C
W: An error occurred during the signature verification. The repository 
is not updated and the previous index files will be used. GPG error: 
http://ftp.ports.debian.org/debian-ports unreleased InRelease: The 
following signatures couldn't be verified because the public key is not 
available: NO_PUBKEY 06AED62430CB581C
W: Failed to fetch 
http://ftp.ports.debian.org/debian-ports/dists/unstable/InRelease  The 
following signatures couldn't be verified because the public key is not 
available: NO_PUBKEY 06AED62430CB581C
W: Failed to fetch 
http://ftp.ports.debian.org/debian-ports/dists/unreleased/InRelease  The 
following signatures couldn't be verified because the public key is not 
available: NO_PUBKEY 06AED62430CB581C
W: Some index files failed to download. They have been ignored, or old 
ones used instead.
ppc64_l4.15.9# apt-key list
gpg: symbol lookup error: /usr/local/lib/libreadline.so.7: undefined 
symbol: PC
ppc64_l4.15.9#


Any thoughts from anybody ?

Dennis