The release-key.asc file contains the release key for this archive. Download and use in the following way: wget https://apt.inguza.net/release-key.asc sudo apt-key add release-key.asc The release key was generated 2018-12-29 with 4096 bits to increase the strength compared to the previous release key which was 1024 bits. After this is done you can add the following line to /etc/apt/sources.list deb http://apt.inguza.net wheezy main or deb http://apt.inguza.net jessie main or deb http://apt.inguza.net stretch main or deb http://apt.inguza.net buster main or deb http://apt.inguza.net bullseye main or deb https://apt.inguza.net wheezy main or deb https://apt.inguza.net jessie main or deb https://apt.inguza.net stretch main or deb https://apt.inguza.net buster main or deb https://apt.inguza.net bullseye main i386 and amd64 architectures supported