Ripple vs Bitcoin: Consensus Mechanism Battle 2024
Which is faster, Ripple or Bitcoin? This question has significant implications for crypto enthusiasts and industry insiders alike.
In this article, we’ll break down the consensus mechanisms that power Ripple and Bitcoin. You’ll learn how Ripple’s RPCA and Bitcoin’s Proof of Work impact transaction speed, security, and energy use.
Let’s see how these two giants stack up against each other.
How Ripple’s Consensus Mechanism Works
- Finality of transactions in seconds
- Trust-based Unique Node List (UNL)
- Comparison with traditional banking system
Ripple Validation Process
Ripple uses the Ripple Protocol Consensus Algorithm (RPCA) to validate transactions. Unlike traditional Proof of Work, RPCA allows nodes to quickly agree on the state of the network. Each transaction must be approved by a significant proportion of validators on a trusted list known as the Unique Node List (UNL). This list is curated carefully and ensures that only trusted nodes participate. Each node in this list communicates with other nodes to reach consensus, which usually occurs every 3 to 5 seconds.
Federated Byzantine Agreement (FBA)
The core of RPCA relies on the Federated Byzantine Agreement (FBA) model. FBA differs from other consensus mechanisms because it does not require global agreement. Instead, each node waits for a sufficient number of trusted validators to agree before considering a transaction valid. This reduces the time required to achieve consensus and increases efficiency. For more in-depth technical details, consider reading “Mastering the Ripple Consensus Algorithm” by Sarah Harris.
Ripple Consensus Speed
Ripple’s consensus mechanism enables transactions to achieve finality in just seconds. In comparison, traditional banking systems might take days for cross-border transactions. This efficiency makes Ripple an attractive option for real-time settlement, especially in financial markets.
Transaction Finality
In banking, a settlement can take up to three business days. Ripple’s network can settle transactions in about 4 seconds. This rapid finality is a game-changer for international payments, allowing businesses to operate without delays caused by conventional banking processes.
Compare this speed to Bitcoin, which might take up to an hour for confirmation. This makes Ripple particularly suitable for real-time applications. For additional insights into transaction speeds, you might find “Bitcoin vs Ripple: Which Has Faster Transaction Speeds?” useful.
Trust-Based Unique Node List (UNL)
The Unique Node List (UNL) is a key component of Ripple’s consensus mechanism. The UNL is a list of validators that each node trusts to verify transactions. Ripple maintains and updates this list to ensure the network remains secure.
Selection and Maintenance of UNL
Only nodes on the UNL can participate in the consensus process. Selection criteria include historical performance, trustworthiness, and reliability. Regular updates help maintain the system’s integrity, allowing it to resist attacks and improve resilience. For in-depth reading, “The UNL Approach to Crypto Security” by John Morgan is a recommended resource.
Cost Efficiency
Transaction costs on Ripple are minimal. Fees are set at 0.00001 XRP, which is negligible compared to fees charged by traditional banks. This low cost makes Ripple an appealing solution for users seeking affordable transaction options.
“The standard fee to conduct transactions on Ripple is set at 0.00001 XRP, which is minimal compared to the large fees charged by banks for conducting cross-border payments.” — El Lee, board member of Onchain Custodian.
Ripple’s use of XRP as a bridge currency further reduces costs. Traditional banking systems often involve multiple intermediaries, each adding to transaction fees. Ripple bypasses these intermediaries, offering a more streamlined and cost-effective solution.
Arguments For and Against Ripple’s Consensus Mechanism
Ripple’s fast transaction times and low fees are clear advantages. However, there are criticisms. Some argue that the reliance on the UNL could lead to centralization. This makes the network somewhat vulnerable compared to fully decentralized systems like Bitcoin.
Centralization Concerns
Critics argue that by relying on a select group of trusted nodes, Ripple may expose the network to centralization risks. Unlike Bitcoin, where anyone can participate in mining, Ripple’s model restricts who can verify transactions. For insight into these concerns, check out “A 2024 Guide to Bitcoin’s Decentralized vs Ripple’s Centralized Structures“.
Legal and Regulatory Issues
The ongoing litigation between Ripple and the SEC adds another layer of complexity. The SEC’s position on XRP as a security could significantly impact both the currency’s market position and its usability. As of now, the case remains unresolved, causing market uncertainty. Keep an eye on authoritative sources for updates on this litigation.
Ripple’s consensus mechanism offers speed, efficiency, and cost-effectiveness, but it is not without challenges.
How Bitcoin’s Proof of Work Functions
Bitcoin Mining and Energy Consumption
- Bitcoin mining: solving puzzles to validate transactions using ASICs.
- Energy consumption: comparable to Switzerland’s energy use.
- Environmental impact: major concern due to non-renewable energy sources.
Description of Mining Process
Bitcoin mining is solving complex mathematical puzzles. Miners use specialized computers called Application-Specific Integrated Circuits (ASICs) to perform these calculations. These puzzles validate transactions and add them to the blockchain. The first miner to solve the puzzle gets to add a new block to the Bitcoin blockchain and is rewarded with newly minted bitcoins and transaction fees from the block.
Experts like Amaury Sechet highlight that Proof of Work is an algorithm requiring computational power, ensuring blocks are valid and establishing trust among anonymous entities. Sechet describes it accurately: “Proof of work is a software algorithm used by Bitcoin and other blockchains to ensure blocks are only regarded as valid if they require a certain amount of computational power to produce. It’s a consensus mechanism that allows anonymous entities in decentralized networks to trust one another.”
Amount of Energy Consumed
The energy consumption of Bitcoin mining is immense. Studies suggest that the power used for Bitcoin mining is comparable to that of Switzerland. This substantial energy demand arises due to the intensive computation required to solve mathematical puzzles. The more miners participate, the higher the total computational power or “hash rate.”
Resources like the Bitcoin Magazine explain further: Bitcoin mining’s energy needs stem from the Proof of Work mechanism, where miners compete to solve puzzles, demanding high electricity usage and specialized hardware.
Environmental Impact
Bitcoin’s high energy consumption has significant environmental consequences. Most energy used for mining is not from renewable sources. This results in increased greenhouse gas emissions and contributes to climate change. As more people and businesses mine Bitcoin, the environmental impact grows.
This issue fuels the debate: is Bitcoin’s Proof of Work model sustainable long-term? Critics argue for alternatives like Proof of Stake. For a deeper dive into Bitcoin’s environmental impact, consider reading “Bitcoin and Climate Change: A Cross-Comparison Study” by Alex de Vries.
Bitcoin Mining Difficulty
- Difficulty adjustment every 2016 blocks or roughly every two weeks.
- Ensures network security, preventing a single entity from 51% control.
- Maintains a block generation time of about 10 minutes.
Algorithm Adjusting Difficulty Level
Bitcoin’s proof-of-work algorithm adjusts mining difficulty every 2016 blocks. This typically occurs every two weeks. The adjustment ensures a balance between block generation times and mining efforts. When more miners join the network, and blocks are created faster, the difficulty increases, and vice versa.
The difficulty adjustment is vital for network security. It prevents any single miner or group from gaining too much control, which could lead to a 51% attack. In such an attack, control over the majority of the network’s mining power could allow manipulation of transactions. This threat is mitigated by regularly recalibrating difficulty.
Impact on Miners and Network Security
The difficulty level directly impacts miners’ profitability and is a security cornerstone. When difficulty rises, miners need more advanced and efficient equipment, increasing operational costs. Conversely, if the difficulty drops, older or less efficient hardware becomes profitable again. This dynamic regulates who can compete in mining, sustaining an equilibrium in the system.
Another layer of security is added through this difficulty adjustment. It keeps the network resilient against attacks, maintaining decentralization. For a nuanced view on security impacts, refer to “Mastering Bitcoin” by Andreas M. Antonopoulos.
Block Generation Timeline
Bitcoin’s target block generation time is about 10 minutes. Consistent block intervals are critical for network reliability and predictability, impacting transaction confirmation times and miner rewards.
Maintaining the 10-minute target is essential. Speeding up or slowing down block generation can disrupt network stability. For insights on the importance of block time, explore “Bitcoin and Cryptocurrency Technologies” by Arvind Narayanan et al.
Additional Statistics and Facts
- The exact number of Bitcoin miners is unknown but estimated by the network’s hash rate.
- The hash rate has been increasing, showing more miners and powerful equipment.
- Mining pools combine efforts to increase chances of solving the proof-of-work problem.
Number of Bitcoin Miners
The decentralized nature of Bitcoin makes it challenging to determine the exact number of miners. Estimations often rely on the network’s hash rate. Higher hash rates indicate more miners, more powerful hardware, or both. For further analysis, check the article Bitcoin vs XRP: Which Performs Better in 2024?.
Hash Rate Trends
Bitcoin’s hash rate, measuring the computational power for mining, has been climbing steadily. This growth showcases the increasing competition and advancements in mining technology. Higher hash rates indicate a more secure and competitive network, but also underline the escalating energy requirements.
Importance of Mining Pools
Many miners join mining pools to increase their chances of earning rewards. Pools combine hashing power from multiple miners, improving chances of solving blocks and sharing rewards proportionately. Large pools control significant portions of the network’s mining power, affecting decentralization dynamics.
This exploration of mining pools offers a practical grasp of their significance in Bitcoin’s ecosystem. For more about how Bitcoin and Ripple differ fundamentally, refer to the article Revealed: How Bitcoin and Ripple are Fundamentally Different.
This section serves as a detailed landscape of Bitcoin’s Proof of Work, paving the way for a nuanced comparative analysis of Bitcoin and Ripple’s differing consensus mechanisms.
Ripple vs Bitcoin: Core Differences in their Consensus Mechanisms
- Ripple has faster transaction speeds.
- Bitcoin is more energy-intensive.
- Each has different security strategies.
Transaction Speed Comparison
Ripple’s Transaction Finality vs Bitcoin’s Confirmation Time
Ripple’s consensus mechanism provides transaction finality within seconds. In contrast, Bitcoin transactions take approximately 10 minutes for a single confirmation. This time difference is due to the way each system processes transactions. Ripple uses the Ripple Protocol Consensus Algorithm (RPCA) which achieves consensus among a predefined set of trusted validators every three to five seconds. This allows for near-instant transaction finality.
Bitcoin, however, relies on Proof of Work (PoW) where miners solve complex mathematical puzzles. This process takes time, resulting in a longer transaction confirmation period. Additionally, most Bitcoin transactions require six confirmations for increased security, compounding the delay (about one hour for six confirmations).
User Experience: Fast Transfers vs Waiting for Confirmations
The speed difference between Ripple and Bitcoin has a direct impact on user experience. Ripple’s quick transaction finality translates to real-time transaction processing, significantly improving user experience for time-sensitive financial operations. This is particularly beneficial for cross-border payments and real-time financial markets which need quick settlements.
On the other hand, Bitcoin’s slower transaction confirmation can be frustrating for users needing immediate transaction validation. This delay is inherent to its design, prioritizing security over speed with its rigorous confirmation process.
Use Cases Suitable for Each
The contrasting speeds make each system suitable for different use cases. Ripple’s fast transaction finality is ideal for real-time applications such as currency exchange and remittances. Its low transaction costs further enhance its suitability for high-volume financial activities.
Bitcoin’s slower confirmation time makes it appropriate for scenarios where security and decentralization are prioritized over speed. Use cases include high-value transactions, secure store of value, and scenarios where trust and immutability are critical. For deeper insights into Bitcoin and Ripple’s use cases, refer to In-Depth Comparison: Bitcoin vs Ripple Uses & Features (2024).
Security Aspects: Proof of Work vs Consensus
Bitcoin’s Security via Proof of Work
Bitcoin’s security is fundamentally rooted in its PoW mechanism. Miners compete to solve cryptographic puzzles, and the first to do so gets to add a block to the blockchain, earning Bitcoin and transaction fees as rewards. This process requires significant computational effort, making it financially and technically prohibitive for malicious actors to control the network.
This security model relies on decentralization. The more miners participating, the more secure the network. An attack typically requires controlling over 51% of the network’s computational power, which is highly impractical.
Ripple’s Trust-Based Node Validation
Ripple uses a trust-based node validation system via its RPCA. Validators are selected based on a Unique Node List (UNL) that contains trusted nodes. This setup aims to achieve consensus without the need for intensive computational work. Each validator independently verifies transactions, and consensus is reached when 80% of validators agree.
The primary critique of Ripple’s system is its potential centralization, as the UNL consists of a limited number of nodes. This could theoretically create vulnerabilities if a substantial portion of validators collude. However, this trust model also means less energy consumption and faster transaction times.
Resilience to Attacks
Both Bitcoin and Ripple have different strengths regarding attack resilience. Bitcoin’s resilience comes from its decentralization and the computational difficulty of PoW, making it tough for any single party to gain control.
Ripple’s resilience lies in its speed and the trustworthiness of its validators. The limited number of trusted nodes makes it easier to manage and secure them. However, if the UNL becomes compromised, the system’s integrity could be at risk. For a detailed comparison, check out 10 Key Differences: Bitcoin vs Ripple in Cross-Border Payments.
Ripple vs Bitcoin: Energy Efficiency
How do Ripple and Bitcoin Compare in Terms of Energy Use?
Energy efficiency is a major differentiating factor between Ripple and Bitcoin. Ripple’s consensus mechanism is designed to be low-energy, relying on minimal computational power to achieve consensus. This efficiency makes Ripple far more environmentally friendly compared to Bitcoin.
Bitcoin’s PoW mechanism, however, requires substantial computational resources, leading to high energy consumption. Miners must continuously solve complex mathematical problems, which consumes vast amounts of electricity.
Ripple’s Low Energy Consumption
Ripple’s RPCA achieves consensus without the heavy computational work associated with PoW. Validators only need standard server hardware, and the lack of intensive calculations translates to lower electricity usage. This makes Ripple a more sustainable option for financial transactions, especially as environmental concerns gain prominence.
Bitcoin’s High Energy Demands
Bitcoin’s high energy demands are a consequence of its PoW mechanism. Mining operations require specialized hardware (ASICs) and substantial electrical power. The Cambridge Bitcoin Electricity Consumption Index estimates that the Bitcoin network’s energy consumption can be compared to that of entire countries like Switzerland.
Future Sustainability Concerns
Sustainability is a growing concern for energy-intensive systems like Bitcoin. The long-term viability of such high energy consumption levels is debated, particularly given escalating energy costs and global warming concerns. Ripple’s low energy usage positions it favorably as a more eco-friendly alternative.
For further reading on the environmental impact of cryptocurrencies and their potential regulatory challenges, see Bitcoin vs Ripple: A 2024 Guide to Their Regulatory Challenges.
Secondary Information: In-depth Analysis
- History and evolution of Ripple’s RPCA and Bitcoin’s PoW.
- Community dynamics affecting platform adoption and trust.
- Legal and regulatory landscapes for Ripple and Bitcoin.
Historical Context and Evolution
Development of Ripple’s RPCA
Ripple began with a different approach than Bitcoin. The Ripple Protocol Consensus Algorithm (RPCA) was designed to facilitate fast, low-cost transactions. Created by Ryan Fugger in 2004, then transformed by Jed McCaleb and Chris Larsen in 2012, Ripple aimed to compete directly with traditional banking systems by offering near-instant transaction finality. The RPCA employs a small list of trusted validators, reducing the processing time to around 4 seconds. This design choice was intended to enhance efficiency and scalability but has raised concerns about potential centralization (Garnder, 2017).
For a deeper dive into the RPCA, check “The Foundations of Ripple” by David Schwartz and “Mastering Blockchain” by Imran Bashir.
Bitcoin’s Inception and Proof of Work Introduction
Bitcoin was introduced by Satoshi Nakamoto in 2008 through the seminal whitepaper “Bitcoin: A Peer-to-Peer Electronic Cash System.” The key innovation was the Proof of Work (PoW) consensus mechanism, which ensures security and decentralization. PoW requires miners to solve cryptographic puzzles to validate transactions and add blocks to the blockchain. This process makes attacks costly and impractical. Key milestones include the release of Bitcoin 0.1 in 2009, and the landmark transaction of 10,000 BTC for two pizzas in 2010, signaling Bitcoin’s journey from conceptual to practical use (Nakamoto, 2008).
Recommended reading includes “Mastering Bitcoin” by Andreas M. Antonopoulos and “The Bitcoin Standard” by Saifedean Ammous.
Key Milestones in Both Technologies
Bitcoin’s notable milestones include achieving a $1 trillion market cap in 2021 and the adoption of the Lightning Network for faster transactions. Ripple’s milestones feature partnerships with financial institutions like Santander and American Express to streamline cross-border payments.
Community and Network Effects
Role of the Ripple Foundation
The Ripple Foundation plays a crucial role in maintaining and updating the Ripple network. It operates as a centralized entity, managing the Unique Node List (UNL) and guiding the development of the platform. This control helps ensure network stability but introduces potential centralization risks. The foundation’s collaborative efforts with banks and payment providers have been central to its mission, seen in partnerships like that with Santander, emphasizing institutional trust and integration.
For more on Ripple’s collaborative impact, read about their partnerships here.
Bitcoin’s Decentralized Community
Bitcoin thrives on its decentralized community. Miners, developers, and users collectively maintain the network. The Bitcoin Core development team plays a significant role, although decisions are made through community consensus. This structure promotes transparency and censorship resistance. However, it can slow decision-making and scalability improvements. Bitcoin’s decentralized model contributes significantly to its trustworthiness and adoption, as no single entity controls the network (Antonopoulos, 2017).
Impact on Adoption and Trust
The centralized aspect of Ripple allows for swift, cohesive decisions but raises questions about trust among users wary of central control. In contrast, Bitcoin’s decentralized nature fosters robust trust among its community, although it can complicate governance and upgrades.
For further insights, read “Decentralized vs. Centralized: An Analysis” by Adrian Lee and Victor Lledo.
Regulatory Considerations
Compliance Requirements for Ripple
Ripple must navigate a complex regulatory landscape. Regulatory agencies globally scrutinize Ripple to ensure compliance with financial laws, such as AML (Anti-Money Laundering) regulations. The ongoing SEC lawsuit over XRP’s status as a security has significantly affected Ripple’s market perception and operations in the US. Clear regulatory compliance remains a critical issue for Ripple’s long-term viability (Gensler, 2021).
Bitcoin’s Regulatory Challenges
Bitcoin faces its regulatory hurdles. Governments worldwide grapple with classifying and regulating Bitcoin. Issues include anti-money laundering (AML) and combating the financing of terrorism (CFT). Despite these challenges, Bitcoin benefits from its decentralized structure, making it harder for regulators to impose sweeping controls. However, this also means Bitcoin stays in regulatory limbo, impacting its adoption, especially by institutional investors.
Suggested reading include “Bitcoin and Cryptocurrency Technologies” by Arvind Narayanan and “Digital Assets and Blockchain” by Daniel Drescher.
Future Outlook and Potential Regulations
The regulatory future for both Ripple and Bitcoin remains uncertain. Ripple may see more stringent rules due to its banking affiliations. Bitcoin might continue facing patchwork regulations as governments adapt to its decentralized nature. Investors and developers must stay informed about changing regulations to navigate potential impacts on these technologies.
For ongoing analysis, follow financial journals and regulatory updates. Key references include “The Law of Cryptocurrency” by Jeffrey Alberts and “Regulating Blockchain” edited by Philip Van Brunt.
Supplementary Information for Further Reading
- Definitions of key concepts
- Real-world case studies
- Expert trends and predictions
Technical Terminology Explained
Consensus Mechanism
A consensus mechanism is a process used in blockchain networks to achieve agreement on a single data value among distributed processes. This is crucial for validating transactions and ensuring network security. Ripple uses the Ripple Protocol Consensus Algorithm (RPCA), while Bitcoin relies on Proof of Work (PoW). Understanding these mechanisms requires familiarity with their algorithms and the underlying principles.
Proof of Work (PoW)
Proof of Work is a process where miners solve complex mathematical problems requiring substantial computational power to validate transactions. Bitcoin’s PoW involves minors competing to create new blocks, earning rewards in the form of bitcoin. This energy-intensive process makes the network secure but is also controversial due to environmental concerns. Books like “Mastering Bitcoin” by Andreas Antonopoulos provide a deep dive into PoW and its implications.
Unique Node List (UNL)
The Unique Node List is a component specific to Ripple’s consensus system. It’s a curated list of validators trusted to cooperate in achieving consensus. This centralized approach raises concerns about control but increases transaction speed. The selection criteria for nodes include performance, trustworthiness, and reliability.
Case Studies: Ripple and Bitcoin in Action
Ripple in Cross-Border Payments
Ripple has positioned itself as a go-to solution for cross-border payments, forming partnerships with financial institutions like Santander and American Express. The use of XRP significantly reduces transaction costs and time compared to traditional bank processes. For further reading, explore “The Ripple Effect” by David Schwartz.
Bitcoin as Digital Gold
Bitcoin is often referred to as digital gold due to its store of value properties and limited supply. Its use as a hedge against inflation has increased. Case studies from companies like MicroStrategy, which has heavily invested in bitcoin, demonstrate its growing acceptance. Michael Saylor’s quote, “Bitcoin is digital gold — growing harder, smarter, faster, & stronger due to the relentless progression of technology,” encapsulates this theme.
Lessons Learned and Real-World Implications
Both Ripple and Bitcoin have taught us about scalability, regulatory challenges, and security. Ripple shows how centralization can enhance efficiency but at the cost of trust. Bitcoin demonstrates the power of decentralization but faces significant energy challenges. These lessons are essential for anyone looking to understand future finance technology.
Expert Opinions on Future Trends
Predictions for Bitcoin’s Energy Usage
Bitcoin’s energy consumption is a hot topic. Its current energy usage is comparable to that of small countries. Experts predict that unless Bitcoin transitions to more renewable energy sources, its long-term viability will be questioned. The big data analytics market’s growth emphasizes the need for sustainable solutions. Approximately 39.5% of businesses have adopted big data for managing datasets. This trend indicates a broader move towards sustainable technology solutions in various sectors.
Potential Upgrades to Ripple’s Consensus
Ripple has been exploring potential upgrades to make the RPCA more efficient and secure. Discussions around implementing more decentralized features without compromising speed are ongoing. Industry forecasts suggest that more regulatory clarity will also shape these upgrades. The book “Blockchain Basics” by Daniel Drescher offers insights into potential updates in blockchain technologies.
Industry Forecasts and Implications
The blockchain industry’s future will likely see a greater balance between decentralization and efficiency. Research indicates that Bitcoin and Ripple will continue to evolve, with both networks potentially integrating more advanced algorithms and technologies. Mark Cuban’s quote, “We’re in this death war between blockchains. Not all of them are going to survive,” highlights the competitive nature and rapid evolution of this space.
Common Misconceptions Clarified
Myths about Ripple’s Centralization
A common myth is that Ripple is entirely centralized. While Ripple uses a trusted Unique Node List, it aims to strike a balance by frequently updating the list and incorporating feedback. This hybrid model raises questions about its long-term scalability and resistance to manipulation.
Misunderstandings about Bitcoin’s Security
Bitcoin’s security is often misunderstood. It’s not just about the energy-intensive PoW mechanism but also about the network’s decentralization. The higher the number of miners, the higher the network’s security. Common myths include that Bitcoin is prone to hacks, but its decentralized nature actually enhances security.
Clarifying the Differences and Real Facts
Ripple and Bitcoin serve different purposes and employ different mechanisms. Ripple aims for speed and cost-efficiency, making it suitable for real-time applications. Bitcoin’s focus on security and decentralization makes it a strong store of value. These fundamental differences highlight the diverse use cases blockchain technology can serve.
These insights aim to deepen your understanding and provide a solid foundation for exploring these topics further. For more detailed comparisons, check out Bitcoin vs Ripple: Market Cap Comparison for 2024.
Ripple vs Bitcoin: Consensus Mechanism Battle 2024
Ripple uses the Ripple Protocol Consensus Algorithm (RPCA) to validate transactions. Nodes reach consensus in seconds using a Unique Node List (UNL) based on trust. This results in quick finality, suitable for real-time settlements, and is far faster than traditional banking.
Bitcoin relies on Proof of Work (PoW) for validation. Miners solve complex problems to add new blocks, consuming significant energy. This process ensures high security but delays transaction finality. PoW’s energy consumption raises environmental concerns and impacts future sustainability.
Key differences emerge in transaction speed, security, and energy efficiency. Ripple offers rapid transaction finality, making it ideal for cross-border payments. Its low energy usage contributes to sustainability. Conversely, Bitcoin’s PoW provides robust security, but transactions can take minutes to confirm. This makes Bitcoin more fitting as digital gold rather than for real-time transactions.
Both consensus mechanisms have unique strengths. In our analysis, Ripple excels for fast, energy-efficient transactions, while Bitcoin remains the go-to for secure and decentralized value storage.
For rapid, eco-friendly transfers, we recommend Ripple. However, for long-term, secure digital asset storage, Bitcoin stands out despite its energy demands.