Sandbox & Testing Environments

CBDC TEST CATEGORY MATRIX

CRITICAL CBDC TEST CASES

WALLET CREATION:
□ Create wallet with valid ID → Success
□ Create wallet with invalid ID → Reject with clear error
□ Create duplicate wallet → Prevent with clear message
□ Create wallet with KYC timeout → Handle gracefully
□ Create wallet in sanctioned jurisdiction → Block appropriately

TRANSACTION PROCESSING:
□ Transfer within limits → Complete in <3 seconds
□ Transfer exceeding balance → Reject immediately
□ Transfer exceeding daily limit → Reject with limit info
□ Concurrent transfers (race condition) → Handle correctly
□ Transfer during maintenance window → Queue appropriately

SECURITY SCENARIOS:
□ Brute force login attempt → Lock after N attempts
□ Session hijacking attempt → Detect and invalidate
□ API rate limit exceeded → Throttle appropriately
□ SQL injection attempt → Block, log, alert
□ Man-in-middle attempt → Detect, terminate

EDGE CASES:
□ Transfer of $0.01 → Handle without rounding errors
□ Transfer at exactly limit → Accept
□ Transfer at limit + $0.01 → Reject
□ Wallet at exact holding limit → Block further receipt
□ Simultaneous transactions → Process in correct order

FAILURE SCENARIOS:
□ Database unavailable → Fail gracefully, queue if possible
□ Payment network timeout → Retry with backoff
□ Partial system failure → Degrade gracefully
□ Complete outage → Display maintenance message
□ Recovery from outage → Reconcile all pending
```

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CBDC SECURITY TESTING PROTOCOL

PRE-LAUNCH REQUIREMENTS:

1. EXTERNAL PENETRATION TEST

2. APPLICATION SECURITY ASSESSMENT

3. INFRASTRUCTURE SECURITY REVIEW

4. CRYPTOGRAPHIC REVIEW

5. RED TEAM EXERCISE

ONGOING REQUIREMENTS:

Continuous vulnerability scanning (weekly)
Quarterly penetration tests
Annual red team exercise
Bug bounty program (post-launch)
Security monitoring and alerting
Incident response testing (quarterly)
```

CBDC-SPECIFIC SECURITY SCENARIOS

FINANCIAL ATTACKS:
□ Double-spending attempt
□ Balance manipulation
□ Transaction replay
□ Race condition exploitation
□ Overflow/underflow attacks

IDENTITY ATTACKS:
□ Account takeover
□ Identity spoofing
□ KYC bypass attempts
□ Privilege escalation
□ Session fixation

CRYPTOGRAPHIC ATTACKS:
□ Key extraction attempts
□ Signature forgery
□ Timing attacks
□ Side-channel attacks
□ Quantum-resistance validation

INFRASTRUCTURE ATTACKS:
□ DDoS resilience
□ API abuse
□ Database injection
□ Network segmentation bypass
□ Cloud misconfiguration exploitation

PRIVACY ATTACKS:
□ Transaction tracing
□ User deanonymization
□ Metadata analysis
□ Data exfiltration
□ Inference attacks
```

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CBDC PERFORMANCE REQUIREMENTS

TRANSACTION THROUGHPUT:
├── Target: Support expected peak × 10
├── Example: 1,000 TPS expected → Test 10,000 TPS
├── Sustain: For 1 hour minimum at 10x
└── Reality: Most retail CBDCs need 100-1,000 TPS

LATENCY:
├── P50 (median): <1 second
├── P95: <3 seconds
├── P99: <5 seconds
└── Measure: End-to-end user experience

AVAILABILITY:
├── Target: 99.99% (52 minutes downtime/year)
├── Measure: Including planned maintenance
├── Components: All user-facing services
└── Monitoring: Real-time, 24/7

CONCURRENT USERS:
├── Support: Expected peak × 5
├── Session management: No degradation
└── Database connections: Pooled, managed

RECOVERY:
├── RTO (Recovery Time Objective): <4 hours
├── RPO (Recovery Point Objective): <1 minute
└── Test: Quarterly DR exercises
```

LOAD TESTING METHODOLOGY

STEP 1: BASELINE
├── Test with minimal load
├── Establish performance baseline
├── Identify single-user metrics
└── Duration: 1 hour

STEP 2: NORMAL LOAD
├── Expected average load
├── Sustained operation
├── All features exercised
└── Duration: 24 hours

STEP 3: PEAK LOAD
├── Expected peak (highest hour)
├── All user types active
├── Background jobs running
└── Duration: 4 hours

STEP 4: STRESS TEST
├── 2x, 5x, 10x peak load
├── Identify breaking points
├── Observe degradation patterns
└── Duration: Until failure

STEP 5: SPIKE TEST
├── Sudden load increase
├── 0 → peak in minutes
├── Test auto-scaling
└── Duration: 30 minutes

STEP 6: ENDURANCE
├── Normal load sustained
├── Identify memory leaks
├── Observe long-term stability
└── Duration: 72+ hours

TOOLS:
├── JMeter, Gatling, k6
├── Realistic user scenarios
├── Distributed load generation
└── Production-equivalent environment
```

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DR TESTING PROTOCOL

QUARTERLY DR DRILL:

Scenario 1: Database Failover
├── Simulate primary database failure
├── Observe automatic failover
├── Verify data consistency
├── Measure: Time to recovery
└── Target: <5 minutes

Scenario 2: Application Failover
├── Simulate application server failure
├── Observe load balancer response
├── Verify session handling
├── Measure: User impact
└── Target: Zero dropped transactions

Scenario 3: Region Failover
├── Simulate complete region outage
├── Activate DR region
├── Verify all services operational
├── Measure: RTO achievement
└── Target: <4 hours

Scenario 4: Data Restoration
├── Simulate data corruption
├── Restore from backup
├── Verify data integrity
├── Measure: RPO achievement
└── Target: <1 minute data loss

DOCUMENTATION:
├── Runbooks for each scenario
├── Decision trees for operators
├── Communication templates
├── Post-mortem process
└── Lessons learned integration
```

CHAOS ENGINEERING APPROACH

PRINCIPLE: "Break things on purpose to find weaknesses"

CHAOS EXPERIMENTS:

Infrastructure Chaos:
├── Kill random instances
├── Network partition simulation
├── DNS failures
├── Storage degradation
└── Clock skew injection

Application Chaos:
├── Memory pressure
├── CPU saturation
├── Thread pool exhaustion
├── Connection pool depletion
└── Slow dependencies

Dependency Chaos:
├── Database latency injection
├── Third-party service failures
├── Message queue delays
├── Cache invalidation
└── Certificate expiration

IMPLEMENTATION:
├── Start in non-production
├── Small blast radius initially
├── Expand gradually
├── Monitor closely
├── Have rollback ready
└── Document learnings

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✅ Production parity matters: Issues caught in staging that mirrors production prevent production incidents.

✅ Security testing is non-negotiable: CBDC systems will be attacked. Testing must find vulnerabilities before attackers do.

✅ Performance testing prevents surprises: Systems that haven't been tested at scale fail at scale.

⚠️ How much testing is enough: There's no perfect answer—it's a risk-based judgment.

⚠️ Whether testing catches all issues: Production will always surface issues not found in testing.

🔴 Skipping security testing for speed: Launching with unaddressed vulnerabilities.

🔴 Testing at 1x instead of 10x: Systems need headroom for unexpected load.

🔴 Never testing disaster recovery: DR that hasn't been tested won't work when needed.

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Assignment: Create a comprehensive test strategy document for a CBDC implementation.

Time investment: 2-3 hours

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Q1: At what multiple of expected peak should performance testing target?
A) 1x B) 2x C) 10x D) 100x
Answer: C

Q2: Minimum frequency for external penetration testing?
A) Weekly B) Monthly C) Quarterly D) Annually
Answer: C

Q3: Which environment should exactly mirror production?
A) Dev B) Integration C) UAT D) Staging
Answer: D

Q4: Target availability for CBDC systems?
A) 99% B) 99.9% C) 99.99% D) 100%
Answer: C

Q5: What is chaos engineering?
A) Random testing B) Deliberately breaking systems to find weaknesses C) Performance testing D) Security testing
Answer: B

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End of Lesson 9