Loading...

Credibility Index: A Solution to Deal with Long-range Attacks in Proof of Stake

Seyyedi Roshkhar, Ali Akbar | 2024

0 Viewed
  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 58085 (19)
  4. University: Sharif University of Technology
  5. Department: Computer Engineering
  6. Advisor(s): Habibi, Jafar
  7. Abstract:
  8. In recent years, the concept of cryptocurrencies and blockchain technology has garnered widespread attention. Blockchain, as the foundational technology of these currencies, has been continuously evolving since its inception, and its applications have extended beyond cryptocurrencies. Blockchain is a distributed and decentralized database among its users, functioning based on their consensus. One of the most widely used consensus mechanisms in blockchain is Proof of Stake (PoS). This mechanism utilizes the stakes of users in the network to validate transactions. One of the most significant threats against this mechanism is long-range attacks. These attacks are similar to 51\% attacks in blockchains with Proof of Work (PoW) consensus mechanisms, with the difference being that in long-range attacks, a malicious actor with a minority stake can create another fork of the blockchain and work on it. Over time and with continuous effort, this fork may mistakenly be recognized as the main chain by honest nodes. The occurrence of a long-range attack can lead to a revision of the blockchain's history, whereby the malicious actor, by creating an alternative chain and promoting it as the main chain, alters the transactions on the blockchain and questions the immutability of the blockchain and majority consensus. This undermines the security and trust in blockchain systems. In this thesis, a solution called the Credibility Index is introduced, focusing on preventing and combating long-range attacks of the reorganization and balancing types, as well as accelerating finality in blockchain systems. This solution prevents reorganization and balancing attacks by modifying block weighting and introducing the Credibility Index. Additionally, by defining its own economic finality rules, it identifies and suppresses malicious activities while enabling the finality of a created block quickly, within the next slot, provided the Byzantine fault tolerance threshold is met. Using this solution ensures blockchain security during network partitioning and establishes a threshold to maintain system liveness
  9. Keywords:
  10. Blockchain ; Ethereum Financial System ; Consensus ; Determinacy ; Long-Range Attacks (LRA) ; Stock Proof

 Digital Object List

 Bookmark

...see more