Plasma Cash: new Scalability solution for the Ethereum Network

Vitalik Buterin, Ethereum co-founder, has announced a new solution to make blockchain more “Scalable”.

What does it mean?

In fact, Blockchain is a technology with some limitations. One of the main of them is related to the fact that all the blocks in the chain are connected in series to one another, hence to read correctly the data collected in the distributed log, it is necessary to read all the blocks.

Vitalik Buterin (source: Forbes — see the profile)

In other words, this means that the entire chain must be downloaded. For example, today the entire Ethereum blockchain already weighs over 400 GigaBytes, and is obviously constantly increasing. The consequence is that we try to limit the blocks size as much as possible to prevent blockchain from increasing too much: this is a limit to the so-called “Scaling”, i.e. the dimensional growth of this technology diffusion.

Buterin’s solution is called Plasma Cash, and was presented on March 9th, 2018 in Paris. It was created by Vitalik together with Joseph Poon, one of the Lightning Network co-creators.

Joseph Poon (source: YouTube — see the profile)

It is about adding a layer of smart contracts which can interact with the main blockchain. The goal is to reduce transaction fees for smart contracts and DApps (decentralized applications). To date there is already a similar solution called Plasma, in which, however, each user needs to download and authenticate each block. Plasma Cash instead (remaining compatible with Plasma) will only require just to pay attention to the blocks containing the coins you want to track.

Plasma is similar to Lightning Network: it is used to make off-chain transactions, using blockchain only as a guarantee of correctness and security. Use blockchains “sons”, created through smart contract.

However, it suffers from a limitation: it has limited scalability, especially in the Ethereum perspective which would like to become a “world computer”, i.e. a basic framework on which to run many decentralized applications. In short, Plasma could be good for the short-term scalability of the Ethereum platform, but not for the long-term one.

To solve the problems of scalability in the long term, we need a more radical approach, like that of Plasma Cash.

To explain this new solution’s advantages, Buterin suggests to imagine a user who deposits a certain amount of ETH in an exchange: with the new solution a Plasma coin, of the same value as the deposited ETHs, would also be generated, and with a single ID.


In this way that coin will be identified in the chain, and at that point to trace those tokens will be sufficient to simply read the position of the specific coin in the chain, without going backwards to read all the previous blocks in which the deposited ETHs have passed.

For now, in reality, this is just an idea still under study (apparently it seems like they are doing tests to verify its proper functioning), but since it was proposed by Buterin it is worthwhile to already consider it.


This article was originally written in Italian by Marco Cavicchioli and translated in English by Stefania Stimolo for NovaMining.