Alephium

The protocol's innovations extend Bitcoin and Ethereum's battle-tested ideas: The BlockFlow algorithm, based on the UTXO model, achieves today's sharding and scalability (code + algorithm paper). It is the first sharding algorithm to support single-step cross-shard transactions, offering the same user experience as a single chain. A simple, elegant PoW-based sharding solution that doesn't rely on a beacon chain. The stateful UTXO model combines the benefits of eUTXO and account models (see code; wiki coming soon). Tokens are first-class citizens, UTXO-based, and directly owned by users rather than contracts. It offers the same expressiveness as the account model, enabling easy DApp development with enhanced security. Supports multiple participants in a single smart contract transaction, with multiple calls packable into one transaction. A novel VM design addresses many key challenges for dApp platforms (see code, wiki). Less IO-intensive. Flash loans are inherently unavailable. Eliminates multiple EVM attack vectors, including infinite approvals, double-dipping, and reentrancy attacks. The UTXO-style fine-grained execution model reduces risk-free arbitrage. Mitigates front-running via randomized transaction execution (see code, wiki). The PoLW algorithm reduces PoW energy consumption over time (research paper). Features adaptive rewards based on hash power and timestamps. Burns internal mining costs when hash power and energy consumption are high.

Alephium is an innovative blockchain protocol designed to enhance scalability, security, and the development experience for decentralized applications (DApps). It achieves this through the introduction of the BlockFlow sharding algorithm, a stateful UTXO model, and a unique virtual machine design, while also utilizing the PoLW algorithm to reduce energy consumption.