An error info occur when to execute
apt-get update .
W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used.
GPG error: http://download.virtualbox.org jessie InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY A2F683C52980AECF
I found an answer:
gpg --keyserver key_server_name --recv-keys A2F683C52980AECF gpg --armor --export A2F683C52980AECF| apt-key add -
There are two
keys.gnupg.net among many public key servers, are they equal?
gpg --keyserver pool.sks-keyservers.net --recv-keys A2F683C52980AECF gpg --keyserver keys.gnupg.net --recv-keys A2F683C52980AECF
Do the two commands take same effect?