Unicorn AcademyBitcoin · lesson 1 of 20
The problem of digital money
A digital file can be copied endlessly. For money this is a problem: if a digital coin were just a file, it could be spent twice. This is called double spending.
Traditional electronic payments solve the problem with a trusted intermediary, the bank, which keeps the ledger of balances and approves every movement.
Bitcoin proposes a different solution: a public ledger kept by thousands of independent computers, which agree on which transactions are valid without a central authority.
Questions
1. What is double spending?
The possibility of spending the same digital coin twice
A file is easy to copy: without a shared ledger the same coin could be spent twice.
2. How do traditional electronic payments solve the problem?
With a trusted intermediary that keeps the ledger of balances
The bank records balances and approves every movement.
3. What solution does bitcoin propose?
A public ledger kept by many independent computers
Consensus among many participants replaces the intermediary.
Next lesson: The birth of bitcoin
Continue from lesson 4
Bitcoin: an online course in 20 short lessons with quizzes and a final certificate, on Unicorn Academy.
This page in other languages
- Il problema del denaro digitale (Italiano)
- Le problème de la monnaie numérique (Français)
- Das Problem des digitalen Geldes (Deutsch)
- El problema del dinero digital (Español)
- O problema do dinheiro digital (Português)
- Проблема цифровых денег (Русский)
- 数字货币的难题 (中文)
- デジタルなお金の問題 (日本語)
- डिजिटल पैसे की समस्या (हिन्दी)
- 디지털 화폐의 문제 (한국어)
- Dijital para sorunu (Türkçe)
- Masalah uang digital (Bahasa Indonesia)
- مشكلة النقود الرقمية (العربية)
- Vấn đề của tiền kỹ thuật số (Tiếng Việt)
- Problem pieniądza cyfrowego (Polski)