Part 11/17:
A notable technical challenge discussed is fungibility, the property that each unit of currency is interchangeable and indistinct. While cash has perfect fungibility—each dollar or euro is identical—Bitcoin's transparent blockchain records traceability, making some coins "tainted" or "dirty" based on their transaction history.
Simon advocates for integrating true fungibility directly into Bitcoin's protocol, akin to Monero or Litecoin's MimbleWimble extension, to prevent blacklisting or devaluation of coins based on their history. He critiques the reliance on third-party mixers or services, arguing that true fungibility must be embedded at the protocol level to avoid dependence on potentially regulatory or malicious third parties.