Four entrepreneurs who have made significant contributions to privacy in the cryptocurrency and blockchain industries are profiled by BeInCrypto. David Chaum, who founded DigiCash to commercialise his ideas for secure digital cash, was the first to propose mix networks for communicating anonymously online. This idea of reordering sets of messages so no one can identify the sender became the core of the privacy browser Tor. Zooko Wilcox-O’Hearn, who co-founded Zcash, added advanced privacy features to Bitcoin’s codebase so that users could disclose information about their transactions selectively. Matthew D. Green was one of the pioneers of the Zerocoin Protocol, which allowed users to convert their bitcoins into an anonymous, untraceable cryptocurrency. Harold Finney was a member of the cypherpunk movement and advocated the use of mix networks in cryptocurrencies to achieve digital privacy. He was also the first person to receive a bitcoin from its creator, Satoshi Nakamoto.