Você precisa instalar o debian-archive-keyring :
The Debian project digitally signs its Release files. This package contains the archive keys used for that.
sudo apt-get install debian-archive-keyring
No Debian Stretch (testing) último aptitude update notou que eu perdi as chaves, então eu decidi removê-las, mas executar apt-key list não mostra as IDs chave e apt-key update está obsoleto e não faz isso, como posso obter o ID da chave expirada?
# apt-key list
/etc/apt/trusted.gpg
--------------------
pub rsa4096 2013-10-10 [SC] [expired: 2016-10-01]
uid [ expired] I2P Debian Package Repository <[email protected]>
pub rsa4096 2013-04-06 [SC] [expired: 2016-04-10]
uid [ expired] KillYourTV Debian repository signing key <[email protected]>
...
Você precisa instalar o debian-archive-keyring :
The Debian project digitally signs its Release files. This package contains the archive keys used for that.
sudo apt-get install debian-archive-keyring