The digital currency Bitcoin has had remarkable growth since it was first proposed in 2008. Its distributed nature allows currency transactions without a central authority by using cryptographic methods and a data structure called the blockchain. Imagine that you could run the Bitcoin protocol on a quantum computer. What advantages can be had over classical Bitcoin? This is the question we answer here by introducing Quantum Bitcoin which, among other features, has immediate local verification of transactions. This is a major improvement over classical Bitcoin since we no longer need the computationally-intensive and time-consuming method of recording all transactions in the blockchain. Quantum Bitcoin is the first distributed quantum currency, and this paper introduces the necessary tools including a novel two-stage quantum mining process. In addition, we have counterfeiting resistance, fully anonymous and free transactions, and a smaller footprint than classical Bitcoin.The digital currency Bitcoin has had remarkable growth since it was first proposed in 2008. Its distributed nature allows currency transactions without a central authority by using cryptographic methods and a data structure called the blockchain. Imagine that you could run the Bitcoin protocol on a quantum computer. What advantages can be had over classical Bitcoin? This is the question we answer here by introducing Quantum Bitcoin which, among other features, has immediate local verification of transactions. This is a major improvement over classical Bitcoin since we no longer need the computationally-intensive and time-consuming method of recording all transactions in the blockchain. Quantum Bitcoin is the first distributed quantum currency, and this paper introduces the necessary tools including a novel two-stage quantum mining process. In addition, we have counterfeiting resistance, fully anonymous and free transactions, and a smaller footprint than classical Bitcoin.

arXiv:1604.01383IEEE International Conference on Blockchain and Cryptocurrency (ICBC)May 1, 201946 citations

Blockchain and Quantum Computing

Brandon Rodenburg, S. P. Pappas

Jan 1, 201715 citations

Impact and Implications of Quantum Computing on Blockchain-based Electronic Health Record Systems

Mukund Pratap Singh, Jagendra Singh, Vinayakumar Ravi +5 more

Aims This study will investigate the integration of quantum computing and blockchain technology of EHR systems, evaluating the potential and major vulnerabilities of the developed blockchain platforms. In addition, through this evaluation, in this paper, transaction capabilities, energy consumption, and quantum susceptibilities of Ethereum, Bitcoin, and Ripple are being evaluated. Further, research gaps on quantum implications and transition strategies to quantum-resistant systems for achieving secure, efficient, and patient-centric Healthcare 4.0 are identified. Background The embedding of quantum computing and blockchain technology within EHR systems represents the next wave of scientific development within the healthcare sector. However, at the same time, emerging quantum capabilities have raised serious vulnerabilities for major blockchain platforms. If Ethereum and Bitcoin display quantum threats regarding their high transaction capacities, then Ripple, with its high rate of transactions, truly presents a high stake in terms of quantum threats. Further, the energy consumption discrepancies pose some environmental impacts and point to the need for research on energy-efficient quantum-resistant systems. Objective This research investigates the potential and vulnerabilities of major blockchain platforms with electronic health record systems in a new quantum computing environment. In that context, this work evaluates transaction capacities, quantum threats, and energy use for platforms like Ethereum, Bitcoin, and Ripple. Additionally, it seeks to identify research gaps and propose transition strategies toward a quantum-resistant system in support of the development of a secure and efficient Healthcare 4.0. Methods This work focused on assessing the potential and vulnerabilities of blockchain platforms under quantum computing threats in EHR systems. We analyzed transaction processing rates, quantum susceptibilities, and energy consumption metrics for the Ethereum, Bitcoin, and Ripple platforms. A complete literature review is presented with respect to realistic quantum implications and practical transition strategies toward quantum-resistant systems oriented to support the development of secure and efficient Healthcare 4.0. Results The evaluations revealed that Ethereum processed 30 transactions per second and Bitcoin processed 7, with each having low quantum vulnerability. Ripple, at 1500 transactions per second, also had significant quantum vulnerabilities. In addition to energy use, Bitcoin consumes 707 kWh per single transaction compared with Ripple's 0.0078 kWh. Other gaps in research existed in real-world quantum consequences and considerations for transitioning to quantum-resistant systems, all of which are vital for making Healthcare 4.0 secure and efficient. Conclusion This has underscored the transformative potential as well as the weaknesses involved in integrating quantum computing and blockchain technologies into EHR. However, Ethereum, Bitcoin, and Ripple vary in their transaction rates; all three face a similar quantum threat while having large differences in energy consumption. These are problems that would call for more research into quantum-resistant systems and strategic implementation. Actualization of a secure, efficient, and patient-centered Healthcare 4.0 will call for proactive research collaboration and strategic efforts towards ensuring technological and environmental sustainability.Aims This study will investigate the integration of quantum computing and blockchain technology of EHR systems, evaluating the potential and major vulnerabilities of the developed blockchain platforms. In addition, through this evaluation, in this paper, transaction capabilities, energy consumption, and quantum susceptibilities of Ethereum, Bitcoin, and Ripple are being evaluated. Further, research gaps on quantum implications and transition strategies to quantum-resistant systems for achieving secure, efficient, and patient-centric Healthcare 4.0 are identified. Background The embedding of quantum computing and blockchain technology within EHR systems represents the next wave of scientific development within the healthcare sector. However, at the same time, emerging quantum capabilities have raised serious vulnerabilities for major blockchain platforms. If Ethereum and Bitcoin display quantum threats regarding their high transaction capacities, then Ripple, with its high rate of transactions, truly presents a high stake in terms of quantum threats. Further, the energy consumption discrepancies pose some environmental impacts and point to the need for research on energy-efficient quantum-resistant systems. Objective This research investigates the potential and vulnerabilities of major blockchain platforms with electronic health record systems in a new quantum computing environment. In that context, this work evaluates transaction capacities, quantum threats, and energy use for platforms like Ethereum, Bitcoin, and Ripple. Additionally, it seeks to identify research gaps and propose transition strategies toward a quantum-resistant system in support of the development of a secure and efficient Healthcare 4.0. Methods This work focused on assessing the potential and vulnerabilities of blockchain platforms under quantum computing threats in EHR systems. We analyzed transaction processing rates, quantum susceptibilities, and energy consumption metrics for the Ethereum, Bitcoin, and Ripple platforms. A complete literature review is presented with respect to realistic quantum implications and practical transition strategies toward quantum-resistant systems oriented to support the development of secure and efficient Healthcare 4.0. Results The evaluations revealed that Ethereum processed 30 transactions per second and Bitcoin processed 7, with each having low quantum vulnerability. Ripple, at 1500 transactions per second, also had significant quantum vulnerabilities. In addition to energy use, Bitcoin consumes 707 kWh per single transaction compared with Ripple's 0.0078 kWh. Other gaps in research existed in real-world quantum consequences and considerations for transitioning to quantum-resistant systems, all of which are vital for making Healthcare 4.0 secure and efficient. Conclusion This has underscored the transformative potential as well as the weaknesses involved in integrating quantum computing and blockchain technologies into EHR. However, Ethereum, Bitcoin, and Ripple vary in their transaction rates; all three face a similar quantum threat while having large differences in energy consumption. These are problems that would call for more research into quantum-resistant systems and strategic implementation. Actualization of a secure, efficient, and patient-centered Healthcare 4.0 will call for proactive research collaboration and strategic efforts towards ensuring technological and environmental sustainability.

The Open Bioinformatics JournalAug 28, 202421 citations

Post-Quantum Security of the Bitcoin Backbone and Quantum Multi-Solution Bernoulli Search.

Alexandru Cojocaru, Juan A. Garay, Aggelos Kiayias +2 more

Bitcoin and its underlying blockchain protocol have recently received significant attention in the context of building distributed systems and foundations of the consensus problem. At the same time, the rapid development in quantum computing makes the threats to cryptography more and more concerning. In this work, we revisit the formal security of the core of the Bitcoin consensus protocol, called the Bitcoin backbone (Eurocrypt 2015), in the presence of quantum adversaries -- i.e. adversaries equipped with quantum computers. We show that the security of the Bitcoin backbone holds under a quantum analogue of the ``honest majority'' assumption that we develop. The critical ingredient of proving security of the blockchain is to analyzing the quantum query complexity of a Chain-of-Proofs-of-Work search problem. This problem in turn reduces to a problem we call multi-solution Bernoulli search, for which we establish its quantum query complexity. This can be viewed as an extension of a threshold direct product theorem to an average-case unstructured search problem. Our proof, adding to active recent efforts, simplifies and generalizes the powerful recording technique due to Zhandry (Crypto 2019). Our analysis indicates that the security of the Bitcoin backbone protocol is guaranteed provided that the number of adversarial quantum queries is bounded so that each quantum query is worth $O(p^{-1/2})$ classical ones, where $p$ is the probability of success of a single classical query to the protocol's underlying hash function. Perhaps surprisingly, the wait time for safe settlement of transactions in the case of quantum adversaries matches (up to a constant) the safe settlement time in the classical case and thus does not result in any further overhead.Bitcoin and its underlying blockchain protocol have recently received significant attention in the context of building distributed systems and foundations of the consensus problem. At the same time, the rapid development in quantum computing makes the threats to cryptography more and more concerning. In this work, we revisit the formal security of the core of the Bitcoin consensus protocol, called the Bitcoin backbone (Eurocrypt 2015), in the presence of quantum adversaries -- i.e. adversaries equipped with quantum computers. We show that the security of the Bitcoin backbone holds under a quantum analogue of the ``honest majority'' assumption that we develop. The critical ingredient of proving security of the blockchain is to analyzing the quantum query complexity of a Chain-of-Proofs-of-Work search problem. This problem in turn reduces to a problem we call multi-solution Bernoulli search, for which we establish its quantum query complexity. This can be viewed as an extension of a threshold direct product theorem to an average-case unstructured search problem. Our proof, adding to active recent efforts, simplifies and generalizes the powerful recording technique due to Zhandry (Crypto 2019). Our analysis indicates that the security of the Bitcoin backbone protocol is guaranteed provided that the number of adversarial quantum queries is bounded so that each quantum query is worth $O(p^{-1/2})$ classical ones, where $p$ is the probability of success of a single classical query to the protocol's underlying hash function. Perhaps surprisingly, the wait time for safe settlement of transactions in the case of quantum adversaries matches (up to a constant) the safe settlement time in the classical case and thus does not result in any further overhead.

Dec 30, 20203 citations

Quantum-Safe Cryptography for Blockchain: Securing Cryptocurrencies Against Quantum Computing Threats"

Sahar Gul

Jul 18, 20250 citations

O(p^{-1/2})

classical ones, where

p

is the probability of success of a single classical query to the protocol's underlying hash function. Perhaps surprisingly, the wait time for safe settlement of transactions in the case of quantum adversaries matches (up to a constant) the safe settlement time in the classical case and thus does not result in any further overhead.