Ethereum's expansion plan: Plasma's past and present (4)

In the previous article, I analyzed that although Plasma technology has encountered setbacks, many researchers are still moving in this direction with perseverance. With the efforts of many participants, including Vitalik, the founder of Ethereum, a new generation of Plasma technology, Plasma Cash, finally came out.

Compared with the previous generation of Plasma technology, Plasma Cash adopts a new data model, so its technical performance is better than Pmasma's MVP. Plasma Cash can completely eliminate the "massive exit problem".

In Plasma Cash, all tokens are defined as non-fungible tokens, which enables the ownership of each token to be strictly defined. That is to say, at any time, the attributes of the token can show its current owner. In this way, the user only needs to pay attention to the tokens he owns instead of monitoring the status of the entire Plasma like the previous generation of Plasma technology.

Plasma Cash also designed a new interactive challenge system that allows users to easily get their assets back even if someone does something evil. It uses a Merkel Tree structure called a "Sparse Merkle Tree".

Using this tree structure, users can easily verify the history and ownership of a token. When someone in Plasma commits evil deeds and wants to steal assets, the real owner of the assets only needs to submit the proof of owning digital assets to Ethereum (including two recent transaction records and the sparse Merkle tree proofs corresponding to these two transaction records) ) to protect their assets.

However, Plasma Cash again introduces a new set of problems. The main problem is that a malicious user or a former owner of a token can initiate malicious requests to defraud assets.

For example, when a malicious user A takes a fancy to the assets of a user B in Plasma, A deliberately submits some false proofs to Ethereum claiming that the assets are his own and wants to withdraw it. At this time, if user B wants to prevent A's malicious attempt, he must submit a certificate to Ethereum within the challenge period, proving that B is the owner of the asset. So in Plasma Cash, users must stay online at least once every two weeks (challenge period) to deal with these illegal requests.

In addition, in order to prove the ownership of a token, users must also maintain all the transaction records of the token and the Merkle tree proofs corresponding to these transaction records, which is also a big burden on storage.

In late 2018, the price of ether hit rock bottom, and the utopian enthusiasm for the digital currency evaporated. Plasma Cash, a new generation of Plasma technology, did not bring much effect to the expansion of Ethereum performance as expected.

In this case, many companies involved in the development of the Plasma Cash client at that time also stopped related research and development work

The entire Ethereum community appears anxious and turbulent. Although there are still teams and researchers still trying new Plasma solutions and ideas, and have indeed developed new technologies, these new technologies and new solutions have also made improvements to Plasma technology in some aspects. But so far, no one in the Ethereum community has the expectation and enthusiasm for Plasma technology.