The more popular Ethereum gets, the more glaring its scalability issues are. Ethereum users have come to expect, though not too happily, the reality that as high as transaction fees are, they are bound to increase and get even higher. Because of the way Ethereum is set up, the overall efficacy of the network tends to suffer as adoption increases.
Scalability, along with decentralization and security, is a part of what is known as the blockchain trilemma. A blockchain that is cheap and fast, like Solana for example, is also likely to be insecure or more centralized, for example. These are the core concerns in the blockchain space — balancing affordability, speed, and sustainability.
Ethereum has prioritized security and decentralization as the most important factors to date, indicated by this table below.
The price to use Ethereum is high, while security is tight and the large network guarantees a high degree of decentralization. Check out this graph, which showcases the expense and difficulty inherent to owning an Ethereum node.
The question, once we see the benefits of Ethereum and its drawbacks, i.e. its place in the trilemma, is this: how can we improve Ethereum without compromising it? While there have been attempts at the core base layer to scale Ethereum, through things like sharding and an imminent shift to a proof-of-stake system, no single scaling solution has proven sufficient to carry out the original Ethereum mission, of decentralizing the internet. The solution is to pivot towards a rollup-centric, modular Ethereum.
As discussed in the last section, zk-Rollups enhance scalability by handling computations off of the blockchain, providing encrypted proof to the “main” blockchain so that the work that happens on the blockchain is minimal. Without getting too technical about the cryptography (here: a deep-dive into the inner-workings), the so-called “validity proof” provided to the Ethereum blockchain will come in one of two forms, either a STARK (scalable transparent argument of knowledge) or a SNARK (succinct non-interactive argument of knowledge). The system works when a secondary program, the one that executes on the main blockchain, confirms and accepts the validity proof.
At this point it’s also worth noting the other flavor of rollup: the optimistic rollup. These are rollups that assume that transactions are valid by default, running computations only in the case of a challenge. (Visit this Medium article for a more in-depth discussion of the differences between the two. You can also check out this graph for a quick breakdown.)
By eliminating the vast majority of the computation, from the main blockchain’s perspective, zk-Rollups deliver true efficiency, airtight security inherited from layer 1 of the blockchain, and massive improvements in affordability, speed, and sustainability, without suffering the deficits of optimistic rollups, such as long fund withdrawal waiting times. These are the reasons that pioneers and thought leaders, including Ethereum creator Vitalik Buterin, point to zk-Rollups as the future of blockchain.
Let’s take a step back. When Ethereum first hit the market, it gained market share rapidly because of its smart-contract technology. Whereas Bitcoin has inspired passions because of what it could do as a currency, Ethereum was capable of doing much more than that. Clogs, lags, and high gas fees all created a gap for competitors like Solana and Avalanche, which stepped in to offer people the cheap, decentralized processing Ethereum couldn’t.
In a sense, we are seeing that process unfold once again: just as the smartphone changed our view of the internet, just as Bitcoin changed our view of currencies, and just as Ethereum changed our view of both of those once more and of computing in general, zk-Rollups will change the public’s view of the role that faster, more efficient network computing can take.
