Research Articles (Computer Science and Informatics)

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Browsing Research Articles (Computer Science and Informatics) by Author "Nel, Wynand"

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    Embedding tamper-resistant, publicly verifiable random number seeds in permissionless blockchain systems
    (IEEE, 2022) Bezuidenhout, Riaan; Nel, Wynand; Maritz, Jacques M.
    Many blockchain processes require pseudo-random numbers. This is especially true of blockchain consensus mechanisms that aim to fairly distribute the opportunity to propose new blocks between the participants in the system. The starting point for these processes is a source of randomness that participants cannot manipulate. This paper proposes two methods for embedding random number seeds in a blockchain data structure to serve as inputs to pseudo-random number generators. Because the output of a pseudo-random number generator depends deterministically on its seed, the properties of the seed are critical to the quality of the eventual pseudo-random number produced. Our protocol, B-Rand, embeds random number seeds that are confidential , tamper-resistant , unpredictable , collision-resistant , and publicly verifiable as part of every transaction. These seeds may then be used by transaction owners to participate in processes in the blockchain system that require pseudo-random numbers. Both the Single Secret and Double Secret B-Rand protocols are highly scalable with low space and computational cost, and the worst case is linear in the number of transactions per block.
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    Permissionless blockchain systems as pseudo-random number generators for decentralized consensus
    (IEEE, 2023) Bezuidenhout, Riaan; Nel, Wynand; Maritz, Jacques M.
    Consensus algorithms that function in permissionless blockchain systems must randomly select new block proposers in a decentralised environment. Our contribution is a new blockchain consensus algorithm called Proof-of-Publicly Verifiable Randomness (PoPVR). It may be used in blockchain design to make permissionless blockchain systems function as pseudo-random number generators and to use the results for decentralised consensus. The method employs verifiable random functions to embed pseudo-random number seeds in the blockchain that are confidential, tamper-resistant, unpredictable, collision-resistant, and publicly verifiable. PoPVR does not require large-scale computation, as is the case with Proof-of-Work and is not vulnerable to the exclusion of less wealthy stakeholders from the consensus process inherent in stake-based alternatives. It aims to promote fairness of participation in the consensus process by all participants and functions transparently using only open-source algorithms. PoPVR may also be useful in blockchain systems where asset values cannot be directly compared, for example, logistical systems, intellectual property records and the direct trading of commodities and services. PoPVR scales well with complexity linear in the number of transactions per block.