Lecture 12 (Bonus): History of Cryptocurrencies

What this lecture covers

This bonus lecture, given by guest speaker Jeremy Clark, steps outside the course's usual focus on Bitcoin itself to survey the decades of digital payment research that came before it. It moves from the basic economics of barter and cash-versus-credit through commercial systems of the 1990s (First Virtual, SET, CyberCash) to the cryptographic e-cash line of work started by David Chaum, and finally to pre-Bitcoin proof-of-work proposals such as Hashcash and Micromint that anticipated pieces of Bitcoin's design.

Because no transcript is available for this video, this guide is built from its title, chapter list and description only.

Key ideas

• Barter and the shift to cash and credit: the chapters open with the basic problem digital payment systems try to solve, moving value between parties without a trusted intermediary present in person.
• Early online payment systems (1994-96): First Virtual, SET (Secure Electronic Transaction) and CyberCash represent competing commercial attempts to secure card-based online payments, each covered with a "post-mortem" on why it did or didn't succeed.
• Chaum's e-cash and blind signatures (1983): David Chaum's cryptographic digital cash, built on blind signatures, aimed to give digital money the privacy properties of physical cash.
• The double-spending problem: a recurring theme connecting e-cash to later systems, including the Chaum-Fiat-Naor (1988) construction and its improvements.
• Tamper-resistant hardware: schemes such as Mondex (1995) tried to prevent double spending using secure hardware rather than pure cryptography.
• Proof-of-work precursors: Hashcash (Adam Back, 1997), Micromint (Rivest and Shamir, 1997) and Hal Finney's reusable proof of work are presented as direct technical ancestors of Bitcoin's mining mechanism.

Walkthrough

Barter, cash and credit (2:32)

The lecture sets up the economic problem of exchanging value and contrasts cash-based and credit-based transactions, including how a credit card transaction routes through an intermediary.

Early commercial payment systems (10:12)

First Virtual (1994) and SET (1996), along with contemporaries from 1994-96 including CyberCash, are covered as competing approaches to securing card payments online, each followed by a post-mortem on its outcome.

Chaum's e-cash and blind signatures (20:48)

David Chaum's 1983 e-cash proposal is introduced along with blind signatures and the cut-and-choose technique, then connected back to the double-spending problem and the 1988 Chaum-Fiat-Naor construction and its later improvements, including DigiCash's commercial variants and their post-mortem.

Tamper-resistant hardware and Mondex (44:10)

Mondex (1995) is presented as an alternative approach that relied on tamper-resistant hardware rather than cryptography alone to prevent double spending, again with a post-mortem on why it did not last.

From minting to proof of work (48:52)

The lecture moves to Hashcash (Adam Back, 1997), explicitly compares it to Bitcoin's mining, then covers Micromint (Rivest and Shamir, 1997) and Hal Finney's reusable proof of work, framing these as the direct technical predecessors of Bitcoin's consensus mechanism.

Before you watch

• Have a basic sense of Bitcoin's mining and proof-of-work mechanism from earlier lectures in this course, since the final chapters compare Hashcash directly to it.
• No transcript was available for this video, so treat the walkthrough above as a guide to its structure rather than a full account of its content.

Check your understanding

1. What problem did commercial systems like SET and CyberCash try to solve for online card payments in the mid-1990s?
2. How do blind signatures help Chaum's e-cash scheme provide privacy similar to physical cash?
3. Why is the double-spending problem central to the history of digital cash before Bitcoin?
4. How did Mondex's use of tamper-resistant hardware differ from Chaum's cryptographic approach to preventing double spending?
5. In what ways do Hashcash and Micromint anticipate Bitcoin's proof-of-work design?