Understanding Blockchain Sharding

Harmony implements blockchain sharding in three dimensions: state, network, and transaction. This multi-dimensional sharding approach is designed to enhance scalability and performance. In state sharding, each shard maintains its own blockchain and state database, allowing validators in each shard to store only a fraction of the entire network’s state. This division ensures that the blockchain can scale with the number of shards, improving storage efficiency and processing speed.

Network sharding involves dividing Harmony’s validator network into separate shards, each with its own set of validators. These validators work closely to reach consensus and synchronize blocks within their shard. This structure allows for efficient communication and consensus achievement among validators, reducing the overhead and latency associated with a single, monolithic blockchain network.

Transaction sharding enables Harmony to process transactions in parallel across different shards. Each transaction is assigned to a specific shard, allowing for concurrent processing and significantly increasing the network’s overall transaction throughput. This method ensures that Harmony can handle a high volume of transactions without compromising speed or efficiency.

Harmony’s sharding mechanism is designed to operate seamlessly, with cross-shard transactions facilitated through a structured approach that ensures eventual atomicity. This means that despite the separation of shards, the network guarantees that transactions across shards are executed in a manner that prevents double-spending, ensuring consistency and integrity across the entire blockchain.

Epochs play a crucial role in Harmony’s sharding structure, marking periods during which the validator committees of shards remain unchanged. The transition between epochs involves the election of new validator committees, ensuring that the network remains dynamic and secure. This periodic rotation of validators across shards enhances security and decentralization, as it prevents any single group of validators from exerting undue influence over the network.

Crosslinks serve as a bridge between shard chains and the beacon chain, ensuring that blocks confirmed in shard chains are recognized and validated by the entire network. These crosslinks not only endorse the canonical status of shard chain blocks but also play a crucial role in recording validator activities, which are essential for block reward calculation and maintaining the network’s integrity.

Harmony’s Fully Scalable Architecture

Harmony’s architecture is designed to be fully scalable, addressing the blockchain trilemma by achieving a balance between decentralization, security, and scalability. The architecture leverages sharding to distribute the network’s load across multiple shards, each capable of processing transactions and maintaining its own state independently. This design allows Harmony to scale linearly as the number of shards increases, without compromising on security or decentralization.

The network’s scalable architecture is underpinned by a robust consensus mechanism, Fast Byzantine Fault Tolerance (FBFT), which ensures rapid block confirmation times and enhances the network’s throughput. FBFT is optimized for performance, allowing Harmony to achieve block finality in just a few seconds, a significant improvement over traditional blockchain systems.

Harmony’s architecture also includes a novel staking mechanism, Effective Proof-of-Stake (EPoS), which is designed to reduce centralization and ensure a fair distribution of rewards among validators. EPoS encourages participation by allowing validators with varying amounts of staked tokens to contribute to the network’s security, ensuring that no single validator or group of validators can dominate the network.

The network’s infrastructure is built on top of the industry-leading peer-to-peer protocol, libp2p, which provides a robust and scalable networking layer. This choice of networking technology ensures that Harmony can efficiently handle the high volume of communication required for shard-to-shard and cross-shard transactions, further enhancing the network’s scalability.

Harmony’s architecture is complemented by a suite of developer tools and protocols designed to facilitate the creation and deployment of decentralized applications (dApps). These tools, combined with Harmony’s scalable infrastructure, provide a conducive environment for developers looking to build scalable and efficient dApps without the limitations of traditional blockchain platforms.

The architecture’s design principles emphasize simplicity, modularity, and future-proofing, ensuring that Harmony can adapt to evolving technological advancements and user needs. This forward-thinking approach positions Harmony as a scalable and versatile blockchain platform capable of supporting a wide range of applications and use cases.

Harmony’s commitment to a fully scalable architecture is evident in its ongoing research and development efforts, which focus on enhancing the network’s capabilities and addressing the challenges associated with blockchain scalability. Through continuous innovation and community engagement, Harmony aims to push the boundaries of what is possible in the blockchain space, driving the adoption of decentralized technologies across various industries.

Secure Random Sharding Explained

Secure random sharding is a cornerstone of Harmony’s approach to achieving a scalable and secure blockchain. This technique involves the random assignment and shuffling of validators to different shards, ensuring that the network remains secure against potential shard-based attacks. The randomness used in the sharding process is generated through a distributed randomness generation algorithm, which is unpredictable, unbiased, verifiable, and scalable.

The security of Harmony’s sharding process is further enhanced by the use of Verifiable Random Functions (VRFs) and Verifiable Delay Functions (VDFs), which provide cryptographic guarantees for the randomness used in validator assignment. This ensures that attackers cannot predict or manipulate the assignment of validators to shards, maintaining the integrity and security of the network.

Harmony’s secure random sharding mechanism also includes a process known as resharding, which periodically reassigns validators to different shards. This process is conducted in a non-interruptive manner, using the “Cuckoo Rule” to ensure that the network remains resilient against slowly adaptive Byzantine adversaries. Resharding enhances the network’s security by preventing attackers from establishing a persistent presence in any single shard.

The use of secure random sharding allows Harmony to maintain a high degree of decentralization and security, even as the network scales. By ensuring that validators are evenly and randomly distributed across shards, Harmony mitigates the risks associated with centralization and enhances the overall security of the blockchain.

Secure random sharding also plays a crucial role in facilitating efficient cross-shard transactions. By ensuring that shards are composed of randomly selected validators, Harmony enables seamless and secure communication between shards, allowing for the efficient execution of cross-shard transactions without compromising the network’s security.

Harmony’s implementation of secure random sharding represents a significant advancement in blockchain technology, addressing key challenges associated with scalability and security. Through this innovative approach, Harmony is able to offer a scalable, secure, and decentralized blockchain platform that is well-suited for a wide range of applications and use cases.

Highlights

• Harmony implements blockchain sharding in three dimensions: state, network, and transaction, enhancing scalability and performance by allowing parallel processing and reduced storage per validator.
• State sharding divides the blockchain and state database into shards, with each shard maintaining its own chain, enabling validators to store only a fraction of the total network state.
• Network sharding organizes validators into separate shards, optimizing consensus and block synchronization within shards and facilitating efficient cross-shard communication.
• Transaction sharding assigns transactions to specific shards for parallel processing, significantly increasing the network’s transaction throughput and efficiency.
• Harmony’s architecture is designed for full scalability, leveraging sharding, a robust consensus mechanism (FBFT), and a novel staking mechanism (EPoS) to balance decentralization, security, and scalability.
• Secure random sharding ensures the random assignment and shuffling of validators to shards, using cryptographic methods (VRFs and VDFs) to protect against shard-based attacks and maintain network integrity.
• The combination of these technical foundations enables Harmony to provide a scalable, secure, and decentralized platform suitable for a wide range of decentralized applications and services.