add counter measures to @DanKnox's cracking attempt

[ghost]

Added counter-measures for @DanKnox's attack vector. Stack check verifies that :set_target only comes from secure_bot_net.rb so that a straight call to :set_target no longer reveals any information unless one of my bots is making the call. There are still some other attack vectors but I'll leave that as an exercise for @DanKnox.

[reedlaw]

This is extremely slow and in my 4 test runs, @DanKnox still comes out on top.

[ghost]

I'm not causing the slowdown. Xor is an extremely cheap operation even with BigInt. The reason it's slow is because @DanKnox is going through a whole bunch of numbers and trying to see if each one is the first secret key. Anyway I'm done with the redesign so I'll send a pull request that removes the entire set of secret identifiers.

[DanKnox]

In my tests, my player caused no noticeable slowdown whatsoever. Iterating through the numbers to find the key is actually quite cheap. My code didn't need to perform any of the calculations that @davidk01's player was performing, as I was matching it against the stored result of his initial calculations. Initial tests of my cracking loop all took far less than a second and are merely exploiting the fact that numbers don't work well as encrypted keys no matter how many calculations you perform to derive them.

However, I understand this trend is not sustainable and I am more than happy to revert my player if it is still causing problems on your end.

[DanKnox]

I also haven't had time to test my player against this new update to his bot net. So far it is looking like he may have blocked all legitimate attacks.

[DanKnox]

Nevermind. I guess @davidk01 already reverted my player for me in his most recent pull request.