content: Security through obsurity does have it place in addition to real security.  You want to increase the cost of hacking you, decrease the number of people paying attention to you, and decrease the value of a hack.  Obscurity can pay off in many of those respects. Switching ssh to another port will decrease the number of chinese script kiddies that know you exist.  Who knows, maybe one of their scripts will work on your ip.  Let's not announce ourselves to them and force them to nmap the entire internet to know you exist.  You should assume you will mess something up in your security at some point hopefully temporarily.  In fact you should assume you have some sort of flaw right now.  You want fewer people knocking at your door when that happens. Who knows, rewriting your ssh command with an alias that uses an id_rsa from another location thus allowing you to empty the one in .ssh could be valuable.  If an automattic resource grabber runs on your machine and scans common key places and transmits them they will miss your real id that could be cracked to reveal a password (the one you encrypted it with). Heck, Linux itself is an example of security throught obscurity.  So is mac. A lot of attacks are automated and they are automated because things are typical.