Blockchain is actually nothing new, it found its first mention in 1983, when todays internet, as we know it, didn’t exist. Since then the basic idea of blockchain was further developed till its major first breakthrough with Bitcoin in 2008. The following is a chronological list of the main actors and their important contributions to the current state of Blockchain technology. Please let me know if I missed a major step, happy to add them right away.
In 1979, Ralph Merkle invented the hash tree principle, which is known in the blockchain as the Merkle tree and is an important element in the composition of a block[1].
In 1983, brilliant cryptologist David Chaum published his first white paper on an electronic currency that guarantees anonymity [2]. In 1995 this was also implemented by the Mark Twain Bank, but never really gained a foothold and was therefore shut down again after 3 years [3]. David Chaum said: "As the web grew, the average level of users dropped. It was difficult to understand the importance of privacy " [4].
In 1997, the proof-of-concept was proposed by Adam Back, also known as Hashcash. At that time it was used to defend against e-mail spam and denial-of-service attacks [5].
In 1998 Wei Dai came up with the idea of the b-money, which for the first time conveyed the idea of making money by solving computational puzzles [6] and is part of today's proof-of-work concept.
In 2005, Hal Finney, the first Bitcoin receiver [7], came up with the concept of "Reusable-Proof-of-Work" (RPOW). This concept was not new and was mentioned by Markus Jabobsson in 1999 [8]. However, he combined his concept with the Hashcash idea of Adam Back and extended it in the sense that a money token (like a bitcoin today) does not have to go through a proof-of-work again, but can be freely exchanged in the network [9].
Nick Szabo was also an important figure, who already in 1997 showed how to further develop e-commerce with Smart Contract [10]. In 2005 he came up with the Bit Gold idea by describing a system of decentralized proof-of-work creation [11].
In October 2008, just one month after the Lehman Brothers went bankrupt and one of the biggest financial crises in history, a person or group called Satoshi Nakamoto published a white paper under the name "Bitcoin: A Peer-To-Peer Electronic Cash System" describing the Bitcoin protocol as we know it today [12]. A few months later, an open source program was released that implemented the new protocol and marked the start of the Bitcoin protocol.
In 2013 the Ethereum project was born with the goal to provide an open blockchain platform with smart contracts, so that everyone can develop and publish their blockchain application on it.
References:
[1] R. C. Merkle, Comments in 2012 about the 1979 paper: A Certified Digital Signature. [Online] Available: http://www.merkle.com/papers/Certified1979.pdf. Accessed on: Apr. 18 2017.
[2] D. Chaum, BLIND SIGNATURES FOR UNTRACEABLE PAYMENTS. [Online] Available: http://www.hit.bme.hu/~buttyan/courses/BMEVIHIM219/2009/Chaum.BlindSigForPayment.1982.PDF. Accessed on: Apr. 18 2017.
[3] D. Goodin, DigiCash loses U.S. toehold: The pioneering Internet firm is losing its toehold in the United States as the only U.S. bank testing its eCash micropayment system is closing the trial. [Online] Available: https://www.cnet.com/news/digicash-loses-u-s-toehold/. Accessed on: Apr. 18 2017.
[4] J. Pitta, Requiem for a Bright Idea. [Online] Available: https://www.forbes.com/forbes/1999/1101/6411390a.html. Accessed on: Apr. 18 2017.
[5] A. Back, Hashcash – A Denial of Service Count Hashcash – A Denial of Service Counter-Measure. [Online] Available: http://www.hashcash.org/papers/hashcash.pdf. Accessed on: Apr. 18 2017.
[6] W. Dai, b-money. [Online] Available: http://www.weidai.com/bmoney.txt. Accessed on: Apr. 18 2017.
[7] H. Finney, Bitcoin and me (Hal Finney). [Online] Available: https://bitcointalk.org/index.php?topic=155054.0. Accessed on: Apr. 18 2017.
[8] M. Jakobsson and A. Juels, PROOF OF WORK AND BREAD PUDDING PROTOCOLS (EXTENDED ABSTRACT). [Online] Available: http://www.hashcash.org/papers/bread-pudding.pdf. Accessed on: Apr. 18 2017.
[9] GitHub, RPOW – Reusable Proofs of Work. [Online] Available: http://nakamotoinstitute.org/finney/rpow/. Accessed on: Apr. 18 2017.
[10] N. Szabo, The Idea of Smart Contracts. [Online] Available: http://www.fon.hum.uva.nl/rob/Courses/InformationInSpeech/CDROM/Literature/LOTwinterschool2006/szabo.best.vwh.net/idea.html. Accessed on: Apr. 18 2017.
[11] N. Szabo, Bit Gold. [Online] Available: http://nakamotoinstitute.org/bit-gold/#selection-7.6-11.10. Accessed on: Apr. 18 2017.
[12] S. Nakamoto, Bitcoin: A Peer-to-Peer Electronic Cash System. [Online] Available: https://bitcoin.org/bitcoin.pdf. Accessed on: Apr. 18 2017.
The original contribution is in German found on www.blockchainbasics.ch which was a school project for the MSc Business Information Systems at ZHAW School of Management and Law Program.