IOTA 1.0 is using PoW.
Is there still a PoW in IOTA 1.5 ?
I have spent more time studying IOTA 2.0 and didn’t see any reference to PoW. Is it definitely removed ?
2 Answers
Proof of work still exists in IOTA and it will not exist in IOTA 2.0. In the abstract of https://arxiv.org/abs/2005.07778 it says,
In this work, we consider a novel IoT-friendly DLT architecture based on directed acyclic graphs, rather than a blockchain, and with a reputation system in the place of Proof of Work (PoW).
I think it is important to note that POW or POS in IOTA is not being used for consensus on double spends; IOTA will use Fast Probability Consensus, an augmented leaderless consensus mechanism to form consensus on double spends.
The crux of any cryptocurrency is to stop double spends, Bitcoin uses POW to make it computationally expensive to commit a double spend on the ledger. Others use POS to de-incentivize double spends. IOTA will use a FPC which is a voting process with converges with high probability.
On IOTA, POW was going to be used for congestion control, to give a computational cost to issuing transactions to stop a single node from having the ability to issue arbitrary amounts of data. Previously they were going to have bursts of IOTA transactions grow the POW difficulty exponentially. But now they are proposing an alternative rate-controller. You can read about the rate controller specification here:
Yes PoW is still a thing in Chrysalis. In version 2.0 I think is going to be dropped and replaces by mana.
