We’re pleased to be joined by the legendary cryptographer and computer scientist, David Chaum. From his early beginnings at Berkley, David pioneered many of the cryptographic techniques used in secure systems and cryptocurrencies today. Blind signatures, which are used in zero-knowledge proofs, and mix networks, used in Tor heavily rely on his work. At the dawn of the Internet, David founded DigiCash, what many believe to be a direct ancestor of Bitcoin. Today, David continues to pursue his mission to bring data privacy to all as his most recent project, Elixxir, aims to create a truly private messaging and payment app with a mass-market appeal.

Topics covered in this episode:

- David’s background as a Ph.D. student at Berkeley and his thesis entitled “Computer Systems Established, Maintained, and Trusted by Mutually Suspicious Groups”
- What drove him to work on cryptography and privacy systems
- His relationship to the early cypherpunk movement
- David’s contribution to cryptography primitives such as blind signatures, undeniable signatures, group signatures and mixers
- The story of DigiCash and how the company was founded
- The idea behind Cyberbucks and why the company ultimately went bankrupt
- Cryptocurrency adoption as a chicken-and-egg problem
- David’s personal views and practices with regards to online privacy
- His thoughts on the blockchain space today and his views on the future of the industry
- His current project, Elixxir, a messaging and payment app which protects users’ data and metadata

Episode links: 

- [David Chaum’s website](https://chaum.com)
- [DigiCash](https://www.investopedia.com/terms/d/digicash.asp)
- [lists.cpunks.org Mailing Lists](https://lists.cpunks.org/mailman/listinfo)
- [DigiCash - Wikipedia](https://en.wikipedia.org/wiki/DigiCash)
- [Blind Signatures for Untraceable Payments](https://www.chaum.com/publications/Chaum-blind-signatures.PDF)
- [DigiCash announcement article from 1994](https://www.chaum.com/ecash/articles/1994/05-27-94%20-%20World_s%20first%20electronic%20cash%20payment%20over%20computer%20networks.pdf)
- [Project Page: Multiparty Computation](https://www.chaum.com/spymasters/)
- [Security without Identification](https://www.chaum.com/publications/Security_Wthout_Identification.html)
- [Elixxir - Home](https://elixxir.io/)
- [Elixxir - Real Cryptography, Real Time: Precomputations in Elixxir](https://elixxir.io/blog/real-cryptography-real-time)
- [Elixxir - Why Mark Zuckerberg wants no privacy, why he wrote his letter, 
and why it won’t help him](https://elixxir.io/blog/why-zuckerberg-wants-no-privacy)
- [Elixxir - Point of Departure](https://elixxir.io/blog/point-of-departure)
- [cMix white paper](https://drive.google.com/file/d/1B1jv03qc8E1kx0kvGFx4blzwXrQepMyy/view)

Sponsors: 
- Vaultoro: Trade gold to Bitcoin instantly and securely starting at just 1mg - http://vaultoro.com
- Trail of Bits: Trust the team at the forefront of blockchain security research - https://trailofbits.com

This episode is hosted by Sebastien Couture & Friederike Ernst. Show notes and listening options: [epicenter.tv/304](https://epicenter.tv/304)