--snip--
POW: It is costly method as you need Hardware(sometimes specialized also)and lot of electricity is used.
For Network big like Bitcoin, 51 % attack cost is too high but for some new coin where network is not so big (or do not have many miners)
51% attack can be successfully executed.
It make coin fully decentralized and anybody is free to mine.
POS: It is cheap method and no specialized hardware is required. Electricity requirement are also minimal.
One who has large stash of the coin will get big share, making rich more richer.
If coin holders want to keep somebody out of network they are able to do so by not distributing there coins outside their network.
Great writeup. I'd also just want to add POS also encourages holding
Agreed, In POS more you hold, more you get in stakes.
POW:
For Network big like Bitcoin, 51 % attack cost is too high but for some new coin where network is not so big (or do not have many miners)
51% attack can be successfully executed.
It make coin fully decentralized and anybody is free to mine.
An 51% attack is completely independent from the consensus algorithm (PoS/PoW).
Decentralization also does not depend on PoS vs. PoW.
Depending on the implementation of the PoS algorithm, mostly anyone can mine.
First ,get your concepts clear,
POS is not mining.
For 51% attack, if you read the URL topic, you will understand that. For 51% attack in POS, I need to hold 51% of coin. Should I attack the coin in which I am the majority holder. Ok Give me an example in which a POS coin suffered or threatened by 51% attack.
POS: It is cheap method and no specialized hardware is required.
It is not cheap, since you have to lock away a big amount of money. It is like receiving interest.
Mining is not profitable for every coin.Even profitable it took time to break even. Coin you are mining now changes it algorithm then all your mining equipment will become useless on very next day. With POS , you do not wait for break even time.
What do you want to say mining equipment's are cheap?
POS:
One who has large stash of the coin will get big share, making rich more richer.
The same applies to PoW:
One who has large stash of money will get a lot of asics (and therefore more hashrate), making rich more richer.
If coin forks itself and start using new algorithm then all the ASIC will be worthless.
POS:
If coin holders want to keep somebody out of network they are able to do so by not distributing there coins outside their network.
Don't Mind, I am just saying if coin creator and his group of friend decided that they will keep all the supply and do transactions between them only , then no body else will get the coin.(Hypothetically possible).