apt  get  update

root@Microknoppix:/home/knoppix#  
root@Microknoppix:/home/knoppix#  
root@Microknoppix:/home/knoppix# apt-get update
Hit:1 http://archive.debian.org/debian buster InRelease
Hit:2 http://archive.debian.org/debian-security buster/updates InRelease                  
Get:3 http://dl.winehq.org/wine-builds/debian sid InRelease [4,699 B]                     
Get:4 http://security.debian.org/debian-security stable-security InRelease [43.4 kB]
Err:3 http://dl.winehq.org/wine-builds/debian sid InRelease
 The following signatures were invalid: EXPKEYSIG 818A435C5FCBF54A Sebastian Lackner (WineHQ packages) <sebastian@fds-team.
de>
Get:5 http://security.debian.org/debian-security testing-security InRelease [48.0 kB]
Err:4 http://security.debian.org/debian-security stable-security InRelease
 The following signatures couldn't be verified because the public key is not available: NO_PUBKEY BDE6D2B9216EC7A8 NO_PUBKE
Y 8E9F831205B4BA95
Err:5 http://security.debian.org/debian-security testing-security InRelease
 The following signatures couldn't be verified because the public key is not available: NO_PUBKEY BDE6D2B9216EC7A8 NO_PUBKE
Y 8E9F831205B4BA95
Reading package lists... Done
W: GPG error: http://dl.winehq.org/wine-builds/debian sid InRelease: The following signatures were invalid: EXPKEYSIG 818A43
5C5FCBF54A Sebastian Lackner (WineHQ packages) <sebastian@fds-team.de>
E: The repository 'http://dl.winehq.org/wine-builds/debian sid InRelease' is not signed.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.
W: GPG error: http://security.debian.org/debian-security stable-security InRelease: The following signatures couldn't be ver
ified because the public key is not available: NO_PUBKEY BDE6D2B9216EC7A8 NO_PUBKEY 8E9F831205B4BA95
E: The repository 'http://security.debian.org/debian-security stable-security InRelease' is not signed.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.
W: GPG error: http://security.debian.org/debian-security testing-security InRelease: The following signatures couldn't be ve
rified because the public key is not available: NO_PUBKEY BDE6D2B9216EC7A8 NO_PUBKEY 8E9F831205B4BA95
E: The repository 'http://security.debian.org/debian-security testing-security InRelease' is not signed.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.
root@Microknoppix:/home/knoppix#  
root@Microknoppix:/home/knoppix#  
root@Microknoppix:/home/knoppix#