kiklo, you can't just claim that 'difficulty' field has any relevant meaning in PoS, unless you know what in code is driving the value of that field. Programming isn't like "the UI is always correct". We have to actually understand what the hell "difficulty" means in this PoS algorithm your code is using. Who knows maybe the programmer is setting some value there what is random or just some gibberish hash of some other data. The programmer might have just wanted to use a consistent set of fields between the two UI (PoW and PoS). I really can't determine any thing from that. I'd have to dig into the code, which really isn't fair since I am not being paid to do that.
Every reference I have studied on PoS has never mentioned a difficulty. There is some talk about strategies that an attacker might use which end up using a lot of computation thus being sort of like PoW, except these aren't in the official client and there is no record of the level of that difficulty recorded (since it is an attack, thus not designed into the protocol).
I am sorry but your point about PoS having difficulty doesn't make sense as far as what I know about PoS and the numerous references I have read. The reason your coin hasn't been attacked is it isn't worth doing so. Ethereum wasn't attacked until the marketcap reached $billion and DAO $160m. It has nothing to do with you not needing to use checkpoints. You just got lucky because your coin doesn't have a large enough marketcap to be worth attacking.
That is not intended to be an insult to your coin effort. Everyone should be free to create and market an altcoin. I am not out to destroy all these smaller coins with my words. If you ever manage to reach your larger goals with it, I assume you'll hire a full time programmer then you will start to deal with some of the issues I am pointing out.
Frankly it is pretty rude of you to argue programming issues with me, as I have written perhaps a few 100,000s lines of code in my lifetime ranging from 68000 assembly to C to C++ to PHP to SQL to Android to Java to Javascript to Scala to Haskell, etc, etc, etc
Not trying to get in a heated debate or anything, but trying to wrap my head around the claims that difficulty is different from PoW to PoS.
From my understanding, both difficulty adjustment algorithms (although altered from coin to coin) are looking at the time it took to produce a new block. If the time is greater than the targeted block time, then difficulty goes down so that it is easier to produce the next block, if the time it took was less than the target difficulty goes up so that it is harder to produce the next block. I don't see any real conceptional difference in the difficulty adjustment algorithms.
I suppose that maybe its an argument about the valid proof required to create that block rather than the adjustment algorithm itself (sorry the thread has been a bit difficult to follow).
Admittedly, I am not a crazy expert programmer. I am still working on my masters in CS, and learn new things all the time. I have however, what I consider a pretty good fundamental understanding of Bitcoin and Peercoin code bases.