The proof-of-stake (PoS) protocol for Ethereum has been a major point of discussion lately, both within the company and the crypto market as a whole. However, there are some people with doubts about the way that it will be added to Ethereum. While at ConsenSys’ Ethereal Summit, Ryan Selkis commented that he doesn’t believe the transition will ultimately go through until 2021.

Selkis, the CEO of the Messari crypto analytics firm, spoke at a panel called “The Smart Contract War is Coming,” saying that there’s significant risks associated with the transition from proof-of-work to PoS. Taking the conversation a step further, Selkis said that the PoS systems “are not proven to work.”

He suggested that the PoW consensus algorithm could be “pretty good” and that it could even work. It is not a secret that the algorithm has been well-established over the last 10 years with Bitcoin, along with Ethereum. He even believes that the PoW algorithm could be the standard for the industry over the course of “at least two or three years.”

The PoS transition, however, will ultimately “take a lot longer than anybody appreciates,” as Selkis says. He added that he sees the algorithm being implemented no sooner than 2021.

As said above, the transition from Pow to PoS has been a major topic of discussion, especially for its promises of scalability, security, and efficiency of the new work. Reports also state that PoS is believed to have greater energy efficiency than its predecessor.

Prysmatic Labs, a sharding development firm, reported on May 7^th that a test beacon blockchain for Ethereum 2.0 was already live. The core developers of this effort maintain that the PoS consensus algorithm will hopefully be ready by June 30^th, 2019, a full two years earlier than Selkis is predicting.