POS: You have to proof you hodl
POW: You have to proof you worked
POS: is a try to create a cost/opportunity from nothing . You can generate infinite parallel chain for free.
In example, there is a conflict between history A and history B, with POW you CAN'T confirm both histories, you have to choose one. So the longest history win.
with POS you can confirm both histories at the same time at not cost.
so to solve this you need a social meta-consensus making POS not necesary at all.
POS security is based on some kind of punishment making it more similar to LN than blockchain. With the difference that LN fail only affect a local environment, a POS fail affect all the global environment.
Hmm, you seem to be confused and think the nothing at stake mythology is a real problem.
Standard PoS wallets don't Multi-stake,
meaning your n@s myth can't currently even be attempted.
If someone did waste their time and make a multi-staking wallet, it would do nothing but waste endless amounts of ram and processing power and energy attempting to stake multiple chains versions simultaneously, essentially becoming closer to a wasteful proof of work than an energy efficient proof of stake.
Example: The more blocks you try and run in parallel the more resources you waste.
Their is zero benefit to even attempting it, which is probably why no one has even bothered to write a multi-staking PoS client, years after the myth was spread
Additional examples:
https://bitcointalksearch.org/topic/m.17135430https://bitcointalksearch.org/topic/m.17136990 https://www.reddit.com/r/NXT/comments/2sewhu/nothing_at_stake_attack_researched_and_deemed_not/3. Nothing-at-stake attack - not possible at the moment! Will be possible when a lot of forgers will use multiple-branch forging to increase profits.
Then attacker can contribute to all the chains(some of them e.g. containing a transaction) then start to contribute to one chain only behind the best(containing no transaction) making it winner. Previous statements on N@S attack made with assumption it costs nothing to contribute to an each fork possible and that makes N@S attack a disaster.
In fact, it's not possible at all to contribute to each fork possible, as number of forks growing exponentially with time.
So the only strategy for a multibranch forger is to contribute to N best forks.
In such scenario attack is possible only within short-range e.g. with 25 confirmations needed 10% attacker can't make an attack.
And attack is pretty random in nature, it's impossible to predict whether 2 forks will be within N best forks(from exponentially growing set) for k confirmations.
So from our point of view the importance of the attack is pretty overblown.
FYI:
The Longest Chain with the Highest Difficulty wins in Proof of Stake as well.
With Proof of Stake , however the number of coins per block and the target speed help determine the true difficulty for a Proof of Stake coin.
hashProofOfStake <= [Coin-age] x [Target]
[Coin-age] = [amount of coins] x [days in stake]
Target is the difficulty adjusted # to make sure the coin meets it's rated block speed.
More blocks staking means higher Target #s.
PoS coins that removed coin age are
hashProofOfStake <= [amount of coins] x [Target]
FYI2:
Your Comparison of Proof of Stake to Lightning network is flawed.
Lightning network is nothing more than an offchain payment system, ie: LN Notes/IOUs for redemption of segwit coins or basically Centralized Banking 2.0
(Any Coin that activated segwit could work on LN, such as litecoin or groestlcoin. Like most offchain systems LN is not limited to bitcoin.)Proof of Stake is a energy efficient Consensus Method for determining the next block chosen.
).
