τι ειναι το bitcoin και πως λειτουργει
https://web-wiki.win/index.php?title=10_Undeniable_Reasons_People_Hate_Εξαργυρωση_bitcoin_σε_ευρω_86953
Bitcoin is an electronic currency which operates free of any main control or the oversight of financial institutions or federal governments. Instead it relies on peer-to-peer software and cryptography.