If you get hung up during release:perform because Maven can't verify the authenticity of a host, then there could be one of two
different problems. The first problem, which is an easy fix, is to go to the command line and use SSH to log in to that host. You
should receive a prompt to add the host to your known_hosts file. If you add the host to your known_hosts file from the command line
SSH, then you should be able to try release:perform again and have more success. There is a chance though that this won't fix maven.
Maven doesn't appear to understand hashed known_hosts files. There is some information here - known_hosts file Hashing.
If your known_hosts file is hashed, you can solve this one of a few different ways. If you perform a deploy:deploy instead of
release:perform, then maven will leave a prompt open for you to type 'yes' and have maven add the host (in a way that Jsch, the library
which provides Maven Wagon with the SSH/SCP functionality, understands) to your known_hosts file. Another option is to remove your
known_hosts file, update your SSH configuration so that it does not hash the hostname in known_hosts and try to log in from the command
line.