Ubuntu error GPG error: ... because the public key is not available: NO_PUBKEY 2EBC26B60C5A2783)

在Ubuntu更新管理員中,出現error如:GPG error: http://packages.medibuntu.org jaunty Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 2EBC26B60C5A2783).
可以輸入以下的指令來獲取公鑰:

sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 2EBC26B60C5A2783