Use Case Scenario Cards

Use Case 1

Global Payment Network

Cross-border remittances and merchant payments

Scenario: A startup wants to build a global payment network for remittances and merchant payments, processing millions of transactions daily across 100+ countries.

Requirements

Throughput: 5,000-10,000 TPS

Transaction Cost: <$0.01 per transaction

Finality: <1 minute for merchant confidence

Geographic Distribution: Nodes in 50+ countries

Regulatory Compliance: AML/KYC integration points

Critical Considerations

Must handle peak loads (Black Friday, holidays)
Users expect "instant" payment confirmation
Network must resist censorship by individual countries
Energy costs impact profitability

Debate Challenge: How does your mechanism balance speed, cost, and censorship resistance for a payment network competing with Visa/Mastercard?

Use Case 2

Enterprise Supply Chain

Multi-party logistics and provenance tracking

Scenario: A consortium of 20 Fortune 500 companies (manufacturers, shippers, retailers) wants a shared blockchain for supply chain tracking from factory to consumer.

Requirements

Participants: 20 known enterprises with legal agreements

Throughput: 1,000 TPS (modest load)

Finality: Instant—no reorg risk for audit trails

Privacy: Confidential transactions between subsets of parties

SLA Requirements: 99.9% uptime, predictable performance

Critical Considerations

All participants are identifiable corporations
Data immutability critical for regulatory audits
No tolerance for probabilistic finality
Sustainability reporting (ESG) is important

Debate Challenge: Why is your mechanism appropriate for a consortium of known businesses with defined trust relationships?

Use Case 3

Gaming & NFT Platform

High-frequency in-game asset trading

Scenario: A blockchain-based MMORPG where players trade items, pets, and land parcels. Millions of daily active users generating 100,000+ transactions per day.

Requirements

Throughput: 2,000+ TPS during peak hours

Transaction Cost: Free or <$0.001 (microtransactions)

Confirmation Time: <2 seconds for good UX

NFT Support: Millions of unique tokens

Upgrade Flexibility: Frequent game updates/patches

Critical Considerations

Players expect traditional game responsiveness
Transaction fees kill microtransaction economy
Game developers need governance control for balance updates
Security matters, but not at the cost of user experience

Debate Challenge: How does your mechanism enable a seamless gaming experience without compromising true ownership of digital assets?

Use Case 4

DAO Treasury Management

Decentralized autonomous organization governance

Scenario: A DAO managing $500M in treasury funds. 50,000 token holders vote on proposals for grants, investments, and protocol upgrades.

Requirements

Governance: Token-weighted voting on all decisions

Security: Maximum resistance to attacks (huge funds at stake)

Censorship Resistance: No single entity can block votes

Transparency: All votes and fund movements are auditable

Long-Term Viability: Must survive for 20+ years

Critical Considerations

Plutocracy concerns: large holders vs. small holders
Voter apathy: how to encourage participation?
Sybil resistance: prevent fake accounts from gaming votes
Emergency responses: can DAO act quickly when needed?

Debate Challenge: How does your mechanism balance democratic governance with security for a high-value autonomous organization?

Use Case 5

Central Bank Digital Currency

National digital currency infrastructure

Scenario: A G20 government is launching a retail CBDC to modernize payment infrastructure. Must serve 100 million citizens with instant, secure, and regulated transactions.

Requirements

Throughput: 100,000+ TPS (Visa-scale)

Finality: Instant—irreversible for central bank settlement

Validators: Central bank + commercial banks (permissioned)

Privacy: Configurable (privacy for users, transparency for regulators)

Resilience: Must handle nation-state level attacks

Critical Considerations

Government requires control over validator set
Zero tolerance for reorgs or probabilistic finality
Energy efficiency for political/ESG reasons
Interoperability with traditional banking infrastructure

Debate Challenge: Why is your mechanism appropriate (or inappropriate) for a sovereign nation's digital currency?

Use Case 6

IoT Device Coordination

Machine-to-machine micropayments and data sharing

Scenario: A network of 1 million IoT devices (sensors, autonomous vehicles, smart meters) that need to exchange data and make micropayments with zero human intervention.

Requirements

Throughput: 50,000+ TPS (many small transactions)

Transaction Cost: $0.0001 or less (micropayments)

Device Constraints: Low compute/memory (Arduino-class devices)

Latency: <100ms for real-time coordination

Permissionless: Devices can join/leave network freely

Critical Considerations

Devices can't run full nodes or stake large amounts
Offline operation: devices may have intermittent connectivity
Sybil resistance without traditional identity
Energy efficiency (battery-powered devices)

Debate Challenge: How does your mechanism enable millions of resource-constrained devices to transact trustlessly?

Instructions: Cut along card borders. Distribute one card to each team during the use case phase. Teams have 3 minutes to argue why their consensus mechanism best fits the scenario requirements.