[Resolvido] Erro de repositório - W: Não existem chaves públicas para os seguintes IDs de chaves

Hoje quando eu fui ao atualizar o sistema operacional vi uma mensagem peculiar como mostra abaixo:
W: Não existem chaves públicas para os seguintes IDs de chaves:
1397BC53640DB551
Toda vez que eu atualizo sistema eu utilizo o gerenciador atualizações do Linux Mint e está aparecendo esse erro. O que eu posso fazer para que essa mensagem não apareça mais ou que esse problema seja resolvido?
W: Não existem chaves públicas para os seguintes IDs de chaves:
1397BC53640DB551
Toda vez que eu atualizo sistema eu utilizo o gerenciador atualizações do Linux Mint e está aparecendo esse erro. O que eu posso fazer para que essa mensagem não apareça mais ou que esse problema seja resolvido?
Entre ou Registre-se para fazer um comentário.
Comentários
[code]sudo apt-get update[/code]
Copia toda a saida dele e cole aqui para nos poder analisar melhor.
wget -q -O - https://dl.google.com/linux/linux_signing_key.pub | sudo apt-key add -
fonte: https://www.google.com/linuxrepositories/
Atingido http://repo.steampowered.com precise InRelease
Ign http://ubuntu-archive.locaweb.com.br trusty InRelease
Obter:1 http://ubuntu-archive.locaweb.com.br trusty-updates InRelease [65,9 kB]
Atingido http://ubuntu-archive.locaweb.com.br trusty Release.gpg
Obter:2 http://ubuntu-archive.locaweb.com.br trusty-updates/main amd64 Packages [756 kB]
Ign http://extra.linuxmint.com rosa InRelease
Ign http://dl.google.com stable InRelease
Ign http://mint-packages.c3sl.ufpr.br rosa InRelease
Atingido http://mint-packages.c3sl.ufpr.br rosa Release.gpg
Atingido http://mint-packages.c3sl.ufpr.br rosa Release
Obter:3 http://ubuntu-archive.locaweb.com.br trusty-updates/restricted amd64 Packages [15,9 kB]
Atingido http://ppa.launchpad.net trusty InRelease
Atingido http://mint-packages.c3sl.ufpr.br rosa/main amd64 Packages
Obter:4 http://ubuntu-archive.locaweb.com.br trusty-updates/universe amd64 Packages [359 kB]
Atingido http://extra.linuxmint.com rosa Release.gpg
Atingido http://security.ubuntu.com trusty-security InRelease
Atingido http://mint-packages.c3sl.ufpr.br rosa/upstream amd64 Packages
Atingido http://mint-packages.c3sl.ufpr.br rosa/import amd64 Packages
Atingido http://mint-packages.c3sl.ufpr.br rosa/main i386 Packages
Atingido http://mint-packages.c3sl.ufpr.br rosa/upstream i386 Packages
Obter:5 http://ubuntu-archive.locaweb.com.br trusty-updates/multiverse amd64 Packages [13,2 kB]
Atingido http://mint-packages.c3sl.ufpr.br rosa/import i386 Packages
Obter:6 http://ubuntu-archive.locaweb.com.br trusty-updates/main i386 Packages [723 kB]
Atingido http://repo.steampowered.com precise/steam Sources
Ign http://archive.canonical.com trusty InRelease
Atingido http://ppa.launchpad.net trusty InRelease
Atingido http://repo.steampowered.com precise/steam amd64 Packages
Atingido http://repo.steampowered.com precise/steam i386 Packages
Atingido http://security.ubuntu.com trusty-security/main amd64 Packages
Atingido http://extra.linuxmint.com rosa Release
Obter:7 http://ubuntu-archive.locaweb.com.br trusty-updates/restricted i386 Packages [15,6 kB]
Obter:8 http://ubuntu-archive.locaweb.com.br trusty-updates/universe i386 Packages [360 kB]
Atingido http://ppa.launchpad.net trusty InRelease
Atingido http://archive.canonical.com trusty Release.gpg
Atingido http://security.ubuntu.com trusty-security/restricted amd64 Packages
Obter:9 http://ubuntu-archive.locaweb.com.br trusty-updates/multiverse i386 Packages [13,6 kB]
Atingido http://ubuntu-archive.locaweb.com.br trusty-updates/main Translation-en
Atingido http://ubuntu-archive.locaweb.com.br trusty-updates/multiverse Translation-en
Atingido http://ubuntu-archive.locaweb.com.br trusty-updates/restricted Translation-en
Atingido http://ubuntu-archive.locaweb.com.br trusty-updates/universe Translation-en
Atingido http://ubuntu-archive.locaweb.com.br trusty Release
Obter:10 http://dl.google.com stable Release.gpg [916 B]
Atingido http://extra.linuxmint.com rosa/main amd64 Packages
Atingido http://ppa.launchpad.net trusty/main Sources
Atingido http://ubuntu-archive.locaweb.com.br trusty/main amd64 Packages
Atingido http://archive.canonical.com trusty Release
Atingido http://security.ubuntu.com trusty-security/universe amd64 Packages
Atingido http://ubuntu-archive.locaweb.com.br trusty/restricted amd64 Packages
Atingido http://ubuntu-archive.locaweb.com.br trusty/universe amd64 Packages
Atingido http://ubuntu-archive.locaweb.com.br trusty/multiverse amd64 Packages
Atingido http://ubuntu-archive.locaweb.com.br trusty/main i386 Packages
Atingido http://ubuntu-archive.locaweb.com.br trusty/restricted i386 Packages
Atingido http://ubuntu-archive.locaweb.com.br trusty/universe i386 Packages
Atingido http://ppa.launchpad.net trusty/main amd64 Packages
Atingido http://ubuntu-archive.locaweb.com.br trusty/multiverse i386 Packages
Atingido http://ubuntu-archive.locaweb.com.br trusty/main Translation-pt_BR
Atingido http://dl.google.com stable Release
Atingido http://ubuntu-archive.locaweb.com.br trusty/main Translation-pt
Ign http://dl.google.com stable Release
Atingido http://ubuntu-archive.locaweb.com.br trusty/main Translation-en
Atingido http://security.ubuntu.com trusty-security/multiverse amd64 Packages
Atingido http://extra.linuxmint.com rosa/main i386 Packages
Atingido http://ubuntu-archive.locaweb.com.br trusty/multiverse Translation-pt_BR
Atingido http://ubuntu-archive.locaweb.com.br trusty/multiverse Translation-pt
Atingido http://archive.canonical.com trusty/partner amd64 Packages
Atingido http://ubuntu-archive.locaweb.com.br trusty/multiverse Translation-en
Atingido http://ubuntu-archive.locaweb.com.br trusty/restricted Translation-pt_BR
Ign http://mint-packages.c3sl.ufpr.br rosa/import Translation-pt_BR
Atingido http://ubuntu-archive.locaweb.com.br trusty/restricted Translation-pt
Atingido http://ubuntu-archive.locaweb.com.br trusty/restricted Translation-en
Atingido http://ppa.launchpad.net trusty/main i386 Packages
Atingido http://ubuntu-archive.locaweb.com.br trusty/universe Translation-pt_BR
Atingido http://ubuntu-archive.locaweb.com.br trusty/universe Translation-pt
Ign http://mint-packages.c3sl.ufpr.br rosa/import Translation-pt
Ign http://mint-packages.c3sl.ufpr.br rosa/import Translation-en
Ign http://mint-packages.c3sl.ufpr.br rosa/main Translation-pt_BR
Ign http://mint-packages.c3sl.ufpr.br rosa/main Translation-pt
Atingido http://security.ubuntu.com trusty-security/main i386 Packages
Atingido http://ubuntu-archive.locaweb.com.br trusty/universe Translation-en
Ign http://mint-packages.c3sl.ufpr.br rosa/main Translation-en
Ign http://mint-packages.c3sl.ufpr.br rosa/upstream Translation-pt_BR
Ign http://mint-packages.c3sl.ufpr.br rosa/upstream Translation-pt
Ign http://mint-packages.c3sl.ufpr.br rosa/upstream Translation-en
Atingido http://archive.canonical.com trusty/partner i386 Packages
Atingido http://ppa.launchpad.net trusty/main Translation-en
Atingido http://security.ubuntu.com trusty-security/restricted i386 Packages
Atingido http://archive.canonical.com trusty/partner Translation-en
Atingido http://ppa.launchpad.net trusty/main Sources
Atingido http://security.ubuntu.com trusty-security/universe i386 Packages
Ign http://dl.google.com stable/main amd64 Packages/DiffIndex
Atingido http://ppa.launchpad.net trusty/main amd64 Packages
Atingido http://security.ubuntu.com trusty-security/multiverse i386 Packages
Atingido http://ppa.launchpad.net trusty/main i386 Packages
Atingido http://security.ubuntu.com trusty-security/main Translation-en
Atingido http://ppa.launchpad.net trusty/main Translation-en
Atingido http://security.ubuntu.com trusty-security/multiverse Translation-en
Atingido http://ppa.launchpad.net trusty/main Sources
Atingido http://security.ubuntu.com trusty-security/restricted Translation-en
Atingido http://ppa.launchpad.net trusty/main amd64 Packages
Atingido http://security.ubuntu.com trusty-security/universe Translation-en
Atingido http://ppa.launchpad.net trusty/main i386 Packages
Atingido http://ppa.launchpad.net trusty/main Translation-en
Ign http://extra.linuxmint.com rosa/main Translation-pt_BR
Ign http://extra.linuxmint.com rosa/main Translation-pt
Ign http://extra.linuxmint.com rosa/main Translation-en
Atingido http://dl.google.com stable/main amd64 Packages
Ign http://repo.steampowered.com precise/steam Translation-pt_BR
Ign http://repo.steampowered.com precise/steam Translation-pt
Ign http://repo.steampowered.com precise/steam Translation-en
Ign http://dl.google.com stable/main Translation-pt_BR
Ign http://dl.google.com stable/main Translation-pt
Ign http://dl.google.com stable/main Translation-en
Baixados 2.323 kB em 13s (169 kB/s)
Lendo listas de pacotes... Pronto
W: Erro GPG: http://dl.google.com stable Release: As assinaturas a seguir não puderam ser verificadas devido à chave pública não estar disponível: NO_PUBKEY A040830F7FAC5991 NO_PUBKEY 1397BC53640DB551