What is RSA? What does a resigner do?

[MaNgO MadDnEsS]

1) Hey, just wondering about getting some info on RSA encryption... what is is exactly? - not so much that i want to try and crack halo 3's RSA... which I cant - but I want to incorporate encryption into my own software... and plus I am a very curious person

2) I have been wanting to ask this for a while, so i thought I'd throw this in to my post - what do rehashers and resigners do? I know that the rehasher changes something in the CON file, after a glance at skatezero's source, but what exactly is it doing. Why I'm asking this is I would like to write my own rehasher to incorporate into my next program, and I would like to do it from scratch. And about the resigner, i'm just wondering, what in the file does it change, what is it doing?

Just to clear things up, for question 2 I am talking about CON rehashing + resigning - and I really want to learn some more about it. Even if someone could simply present me with the problems that need to be solved, I'd find it fun to try and write one from scratch without copying someone else or using their methods.

thanks and sorry for the wall of text lol,
-ajp

[Eazy B]

well we ( people who have the con mapped out ) dont generally give that out because its useless. Basically the RSA is used to encrypt the signature of the file at a certain offset. The RSA is what made it so hard for us to do in the first place, the keys are unbreakable so we had to circumnavigate this by getting the private key itself and using it to resign.