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PHANTOM and GHOSTDAG: A Scalable Generalization of Nakamoto Consensus

This paper introduces PHANTOM and GHOSTDAG, two protocols that generalize the Nakamoto consensus to directed acyclic graph (DAG) topologies. The traditional blo

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Abstract

This paper introduces PHANTOM and GHOSTDAG, two protocols that generalize the Nakamoto consensus to directed acyclic graph (DAG) topologies. The traditional blockchain structure restricts throughput by forcing a linear order of blocks, often leading to stale blocks and network inefficiency. The authors present a mechanism where blocks can be mined in parallel and integrated into a DAG, while still ensuring a robust total ordering of transactions. PHANTOM provides a theoretical solution for a BFT-like consensus in a PoW-based network, while GHOSTDAG offers a scalable, highly efficient implementation that allows for fast confirmation times without compromising security. These contributions are instrumental in understanding how to maintain the decentralization properties of Proof of Work while breaking the scalability constraints of linear chains. The analysis provides deep insights into block-DAG structures and the mathematical proofs required to guarantee network security in non-linear topologies. Authors: Yonatan Sompolinsky, Shai Wyborski, Aviv Zohar Publication: IACR ePrint Archive Publication date: 2018-01-01

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Key findings

  • Generalizes Nakamoto consensus to DAGs.
  • Allows parallel block production without creating security vulnerabilities.
  • Introduces GHOSTDAG for efficient ordering of blocks in a DAG.
  • Demonstrates significant throughput improvements over linear PoW chains.

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Citation

Yonatan Sompolinsky, Shai Wyborski, Aviv Zohar (2018). PHANTOM and GHOSTDAG: A Scalable Generalization of Nakamoto Consensus. IACR ePrint Archive. https://eprint.iacr.org/2018/104.pdf
Canonical knowledge ID: research:phantom-and-ghostdag-a-scalable-generalization-of-nakamoto-consensus