{
  "version": "2026-10-01.1",
  "type": "synthetic educational cases; not measured experiments",
  "questions": [
    {
      "id": "change",
      "title": "Which output is change?",
      "scenario": "Synthetic wallet record: input 0.02000000 LTC; output A pays the invoice 0.01000000 LTC; output B, verified in the sender’s wallet, is 0.00999718 LTC. The fee is 0.00000282 LTC.",
      "options": [
        "Output A",
        "Output B",
        "The fee is a third output"
      ],
      "correct": 1,
      "explanation": "The sender’s own wallet identifies B as change. 0.01000000 + 0.00999718 + 0.00000282 = 0.02000000 LTC. The fee is the input/output difference, not an output. An unfamiliar public transaction alone would not prove who owns B.",
      "link": "/transaction-lab/#flow"
    },
    {
      "id": "address",
      "title": "Does the displayed address match?",
      "scenario": "Synthetic fixture only. Trusted invoice: LLnCCHbSzfwWquEdaS5TF2Yt7uz5Qb1SZ1. Proposed destination: LLnCCHbSzfwWquEdaS5TF2Yt7uz5Qb1SZ2. Never send funds to these examples.",
      "options": [
        "Continue because the prefix matches",
        "Stop and obtain the complete address again",
        "Send a small amount to see who answers"
      ],
      "correct": 1,
      "explanation": "The final character differs. A matching prefix does not establish the same address; the changed Base58Check fixture also fails its checksum. Recheck the full address through a trusted channel and on the signing device. A checksum-valid address would still not prove the intended recipient owns it.",
      "link": "/qr-inspector/"
    },
    {
      "id": "credit",
      "title": "Confirmed, but the account is still empty",
      "scenario": "Synthetic case: the synchronized node reports six confirmations for the exact deposit address and amount. The receiving service’s stated threshold is twelve. Its account has not been credited yet.",
      "options": [
        "The blockchain payment failed",
        "Send the payment again",
        "The chain payment is confirmed; the service threshold is not met"
      ],
      "correct": 2,
      "explanation": "Blockchain confirmation and internal service credit are separate states. Six is below this hypothetical service’s twelve-confirmation requirement. Save the transaction ID, check the actual current policy and monitor the original transfer. Do not send a duplicate. Twelve is an exercise assumption, not a universal exchange rule.",
      "link": "/learn/missing-payment/"
    },
    {
      "id": "qr",
      "title": "The QR changed the amount",
      "scenario": "Synthetic invoice: 0.25000000 LTC. The decoded payment URI says amount=2.50000000 and includes the label “0.25 LTC invoice”. The destination matches.",
      "options": [
        "Pay 2.5 LTC because the address matches",
        "Pay because the label shows 0.25",
        "Stop: the numeric amount is ten times the invoice"
      ],
      "correct": 2,
      "explanation": "A label is descriptive text; it does not override the numeric amount. 2.5 / 0.25 = 10. Compare the decoded address and amount with the independently agreed invoice before signing. Do not assume a wallet parser, QR image or familiar label authenticates the request.",
      "link": "/qr-inspector/"
    }
  ]
}