[j9461701]

Here is an article on this topic that goes heavily in depth on the topic:

http://toughsf.blogspot.com/2018/04/permanent-and-perfect-st...

Note that this is for strategic level stealth, which is to say your enemy doesn't even know you're in system. Tactical level stealth is vastly easier, and can be as simple as launching several hundred thousand heated decoys into system before entering yourself - one of these is the attacker, can you find which?

This last strategy is actually what we'd implement if ever anyone tried to seriously develop anti-ICBM technology.