Quote from: neiman on May 01, 2016, 03:42:36 PM

There seems to be a consensus of some people here that PoS is not secure, but I didn't see anyone elaborate as to why. Is it the monopoly problem or is there something else?

Please (really, pretty please) don't send me to Google it. I'm a newb, I admit, but I also spent a while reading the PoS vs. PoW posts and articles, and couldn't find any other consensus argument beside the monopoly problem.

IIRC there are some academic papers on the topic, however I don't have any interesting links to hand.

There are some deep problems with POS. The election of who should stake *should* be a lottery that participants have no control over. One vulnerability arises because the election process relies on the block chain to generate entropy. Elected people get to write to the block chain, thus changing who should stake next.

Without something like POW, it's possible for someone to retroactively take the block chain, alter it so *they* are chosen, and then they can create the next block. He can even produce a block that allows him to stake again.. and so on.

POW prevents this, making more difficult with every block to rewrite the chain. POS doesn't have anything like this, the CPU power required to grind variations of the chain which favour the attacker is rather small.