WEBVTT 00:00.000 --> 00:15.280 Who invented blockchain? 00:15.280 --> 00:21.840 The idea behind blockchain technology was described as early as 1991 by research scientists 00:21.840 --> 00:25.240 Stuart Haber and W. Scott Stornetta. 00:25.240 --> 00:30.760 The two introduced a computationally practical solution for time stamping digital documents 00:30.760 --> 00:34.000 so that they cannot be backdated or tampered with. 00:34.000 --> 00:38.080 The system used it a crypto graphically secured chain of blocks to store the timestamp 00:38.080 --> 00:39.600 of documents. 00:39.600 --> 00:44.920 In 1992, Merkel trees were incorporated into the design, making it more efficient by 00:44.920 --> 00:48.320 allowing several documents to be collected into one block. 00:48.320 --> 00:54.040 However, this technology went unused and the patent lapsed in 2004, four years before 00:54.040 --> 00:56.120 the inception of Bitcoin. 00:56.120 --> 01:01.360 In 2004, computer scientist and cryptographic activist Hal Finney introduced a system 01:01.360 --> 01:08.520 called RPOW or reusable proof of work to solve the so-called double spending problem. 01:08.520 --> 01:13.160 Double spending is a potential problem in a digital cash system where a cryptocurrency 01:13.160 --> 01:19.360 or any digital asset can be copied and used more than once, like pirated movies or music. 01:19.360 --> 01:24.160 Finney's RPOW system solved this problem by keeping the ownership of tokens registered 01:24.160 --> 01:28.960 on a trusted server that was designed to allow users anywhere in the world to verify their 01:28.960 --> 01:32.240 correctness and integrity in real time. 01:32.240 --> 01:36.920 RPOW can be considered an early prototype and a significant early step in the history 01:36.920 --> 01:38.440 of cryptocurrencies. 01:38.440 --> 01:43.760 Then, in late 2008, a white paper introduced a decentralized peer-to-peer electronic 01:43.760 --> 01:46.120 cash system called Bitcoin. 01:46.120 --> 01:50.040 The white paper was posted to a cryptography mailing list by a person or group using 01:50.040 --> 01:52.920 the pseudonym Satoshi Nakamoto. 01:52.920 --> 01:57.320 Bitcoin solves the double spending problem with a decentralized peer-to-peer protocol 01:57.320 --> 02:00.320 for tracking and verifying transactions. 02:00.320 --> 02:06.160 In short, Bitcoin's mind for a reward using the proof of work mechanism by individual miners 02:06.160 --> 02:09.880 and then verified by the decentralized nodes in the network. 02:09.880 --> 02:14.680 On the 3rd of January 2009, Bitcoin came into existence when the first Bitcoin block 02:14.680 --> 02:19.240 was moneyed by Satoshi Nakamoto, who received a reward of 50 Bitcoins. 02:19.240 --> 02:21.840 The first recipient of Bitcoin was Halfinet. 02:21.840 --> 02:26.320 He received 10 Bitcoins from Satoshi Nakamoto in the world's first Bitcoin transaction 02:26.320 --> 02:28.960 on the 12th of January 2009. 02:28.960 --> 02:35.480 Then, in 2013, Vitalik Bhutaran, a programmer and a co-founder of the Bitcoin magazine, stated 02:35.480 --> 02:40.400 that Bitcoin needed a scripting link which for building decentralized applications. 02:40.400 --> 02:44.640 He started the development of a new blockchain-based distributed computing platform called 02:44.640 --> 02:49.560 Ethereum, that featured a scripting functionality called Smart Contracts. 02:49.560 --> 02:53.840 Smart Contracts are programs or scripts that are stored, deployed, and executed on the 02:53.840 --> 02:55.520 Ethereum blockchain. 02:55.520 --> 02:58.920 They can be used to make a transaction if certain conditions are met. 02:58.920 --> 03:03.440 For example, developers are also able to create and publish applications that run on the Ethereum 03:03.440 --> 03:04.440 blockchain. 03:04.440 --> 03:09.760 These applications are usually referred to as decentralized applications or DApps, and 03:09.760 --> 03:13.640 there are already many DApps running on the Ethereum blockchain. 03:13.640 --> 03:18.760 The Ethereum blockchain builds on the decentralized and distributed architecture of Bitcoin, but 03:18.760 --> 03:24.520 by introducing Smart Contracts, which support an ecosystem of DApps, Ethereum expands beyond 03:24.520 --> 03:26.640 Bitcoin's core functionality. 03:26.640 --> 03:28.640 Payment Platform 03:28.640 --> 03:35.600 Ethereum has also given rise to other innovations, including decentralized finance or DeFi applications. 03:35.600 --> 03:39.720 Beyond the Bitcoin and Ethereum blockchains, there have been other innovations, such as 03:39.720 --> 03:44.840 alternative consensus mechanisms, to the proof of work mechanisms used by Bitcoin and Ethereum 03:44.840 --> 03:45.840 networks. 03:45.840 --> 03:51.400 Today, blockchain technology is gaining a lot of mainstream attention, and its application 03:51.400 --> 03:54.800 is no longer limited to cryptocurrencies. 03:54.800 --> 03:59.840 Blockchain is used in a wide range of applications and industries, including healthcare, supply 03:59.840 --> 04:03.960 chain, gaming, digital identity, governance, and energy.