What is Fast Finality and How Does Everscale Plan to Achieve It?
Speed is a crucial aspect of blockchain technology, but it extends beyond raw throughput measured in transactions per second (TPS). Another vital factor defining a network’s rapidness and usability is finality, which determines the speed at which transactions are confirmed.
In this article, we dive into the concept of finality, its significance for everyday users, and Everscale's approach to reaching the state of fast finality.
What is Finality in a Blockchain?
Every transaction on a blockchain is not executed instantaneously. When a user sends his tokens to another address, first it must get confirmed by miners (when it comes to Bitcoin and similar Proof-of-work blockchains) or validators (in Proof-of-Stake networks), along with other transfers and additional data.
After a transaction is confirmed, it gets included in the next block, making it an integral part of the distributed ledger. This state of a transaction is called finality.
Why Does Finality Matter?
Finality determines how quickly a user-initiated transaction is confirmed. Many legacy blockchains have low finality due to their small transaction capacity, meaning a user has to wait a significant amount of time until his transfer gets confirmed.
Moreover, prolonged finality creates a space for exploits, specifically, double spending. The latter means that, if there is a substantial time gap between the initiation and confirmation of a transaction, malicious actors may attempt to take advantage of that by spending the same balance twice.
Another challenge stems from decentralization. While a higher number of nodes generally enhances blockchain security, it also prolongs the finality process, negatively impacting overall network security and usability.
Reducing finality time to a bare minimum, along with keeping the blockchain consistent and decentralized, is the challenge.
Finality in Synchronous and Asynchronous Blockchains
Many finality issues arise from a certain blockchain design, in particular, its synchrony.
In synchronous blockchains, the confirmation process is linear across the entire network, i.e. all validators (nodes) must synchronize with each other and can confirm only one transaction from one user at once. This is true for Ethereum, Bitcoin, and many other networks.
This is not the case in asynchronous blockchain networks, where nodes can validate separate transactions without the need to continually synchronize between one another, keeping a single network state. In the context of finality, it means that initiating one transaction might generate a chain of operations.
In Everscale, a nominal finality for one transaction equals the time from initiating a transaction by a user and its inclusion in a block of the masterchain, which is about 3 seconds. This is already faster than most existing blockchain platforms.
But it is not enough to be called a fast finality. In the asynchronous network that is Everscale, a desirable outcome is the result of processing multiple operations, not one. Hence, the finality of a single transaction loses significance. Instead, it is the finality of an entire chain of operations related to a transaction that matters.
Fast Finality in Everscale is More Than a Confirmed Transaction
While finalizing a single transaction swiftly is enabled in Everscale by design, this asynchronous blockchain performs a much more complex logic that might consist of not one but a chain of transactions.
For example, this message triggered more than 5,000 transactions, with the last one finalized in about 2 minutes. The fast finality of such composite operations fast for a user is the real challenge for Everscale, which is currently being solved by its developers.
Everscale has a modular structure, consisting of the masterchain and numerous workchains that carry smart contracts. Under heavy load, a workchain is able to split into so-called threads that provide the sharding of computational resources.
In the context of finality, it means that a chain of operations within one transaction can be split between threads to be executed concurrently. However, synchronizing the process requires the new master block, which hinders finality.
Addressing this issue is what Everscale engineers call the fast finality: if a number of threads in a workchain increases for higher capacity, the finality of even the complex operations must stay within the standard time frame for a user.
Everscale's Strategy for Achieving Fast Finality
Recognizing the paramount importance of fast finality, Everscale developers have unveiled plans to integrate it into our network as outlined in the recently published 2024 roadmap.
A few solutions for enabling fast finality are currently on the table.
Firstly, it is a Soft Majority Fault Tolerant (SMFT) consensus algorithm. Highly anticipated, SMFT is planned to facilitate concurrent processing of multiple chains within a single workchain (data shard), so the network security would benefit from the increase of validators in Everscale. Essentially, SMFT will enforce dynamic sharding, a feature designed in the Everscale protocol to ensure continuous scalability.
Furthermore, engineers are exploring the potential of utilizing Directed Acyclic Graph (DAG) technology for fast finality. This technology, present in decentralized networks like Aptos and Sui, organizes transactions in a graph-like structure where each transaction references multiple previous transactions directly.
By allowing concurrent validation of transactions rather than sequential validation as in linear blockchains, DAG has the potential to reduce confirmation times, ultimately leading to faster finality.
Conclusion
Fast finality stands as a critical component of blockchain technology, impacting transaction confirmation times and user experience.
While various approaches exist, Everscale strives to reach new heights: leave the paradigm of the single transaction finality, focusing on keeping the prompt confirmation of even complex transactions under the high load, when the sharding takes place.
Everscale developers plan to tackle this in 2024 by implementing new technologies, such as DAG and SMFT. With these advancements, Everscale gets the chance to take on the status of a truly fastest blockchain.
