Cardano’s Hydra and Ethereum’s Plasma: Who Copied Who?

Key Takeaways

• Ethereum and Cardano are two blockchains at loggerheads.
• Now, their fans are arguing about a new blog post from Vitalik Buterin.
• Critics say Ethereum’s Plasma is simply copying Cardano’s Hydra.

Ethereum co-founder Vitalik Buterin recently posted a proposal  to revive Plasma , an earlier scaling approach, in response to major advancements in zero-knowledge proofs. Meanwhile, rival blockchain Cardano continues to develop Hydra , its own layer-2 scaling solution. This has reopened debates on whether the projects are copying each other’s ideas on blockchain scaling.

What Is Plasma?

First proposed in 2017, Plasma aims to enable faster and cheaper transactions on Ethereum by moving some data and computation off the main blockchain while retaining security guarantees. This is achieved by using sidechains that run parallel to the main Ethereum chain and only occasionally batch-commit data to the mainchain.

However, Plasma faced challenges around client-side data availability and complex exit games. Buterin’s latest proposal  outlines technical improvements to Plasma, particularly using zero-knowledge proofs to enable validity proofs for off-chain transaction batches. This could resolve issues around data availability and withdrawal game complexity.

What Is Hydra?

Proposed in 2020, Hydra takes a different architectural approach by using state channels instead of sidechains. State channels allow transactions between two parties to be conducted instantly and freely off-chain, with only the final settlement being committed to the main Cardano blockchain.

The key difference from Plasma is that state channels manage security and state progression requirements between channel participants instead of a separate chain operator. This avoids some pitfalls of sidechains but has liveness dependencies on the mainchain.

Some critics are saying Ethereum’s revisited Plasma is essentially equivalent  to Cardano’s Hydra, but with the footnote that Cardano’s use of an Unspent Transaction Output (UTxO) model makes implementing it easier. “It seems to me that #Cardano is going in the right direction and #Ethereum is the one catching up,” said one pro-Cardano commentator .

Iterating On Shared Ideas

The copycat accusations come amidst a bitter relationship between Ethereum and Cardano founders. Steven Nerayoff, the former Ethereum advisor, swiftly criticized  Buterin’s Plasma proposal. He accused Buterin of copying rival blockchain Cardano’s Hydra scaling approach.

He labeled Buterin’s decision to part ways with Cardano founder Charles Hoskinson early on as a “major mistake.” The irony, Nerayoff asserts, is Ethereum emulating the very person they once dismissed.

However, when it comes to Hydra’s and Plasma’s similarities, there are certainly conceptual similarities between using secondary chains or channels to enable faster processing. However, the architectures have fundamentally distinct security assumptions and trade-offs.

Additionally, building on existing areas of research is quite common in cutting-edge fields like cryptography. For example, Buterin’s proposal leverages recent advances in succinct zero-knowledge proofs to improve Plasma. Scientific progress often works by incrementally improving earlier theoretical foundations. Crypto developers are also known to get a little bitchy from time to time.

Ongoing Quest For Scalability Solutions

Scalability remains one of the most pressing issues hampering mainstream blockchain adoption. Both Ethereum and Cardano are leading the charge in exploring layer-2 scaling approaches to meet user demands.

The success of Plasma, Hydra, or any other credible scaling solution will be a boon for the entire blockchain and crypto industry. It may be productive to view the problem through a lens of open intellectual discourse rather than territorial copying accusations between projects. Doing so can keep the advancement of scalability firmly tied to solving user needs.