Blockchain
 Blockchain  (surveillance technology?)   | |
|---|---|
| Start | 1991 |
| Interest of | • Everipedia • Phil Jolley |
| Subpage(s) | •Blockchain/Consensus |
| ID that allegedly can not be forged, perfect for tagging every person in the world. | |
| Alison McDowell asks if it is prudent to place our "trust" in a technology of unknown origin? Who or what 'Satoshi Nakamoto' actually is and whose interests this invention advances. Why restructure the world's social and economic structures around this code? What would it mean to live life on a ledger? |
A Blockchain (or block chain) is a method of storing a list of entries, which cannot be changed easily after they are created. This also applies to the list. This is done by using several concepts from cryptography, including digital signatures and hash functions. In very basic terms, a blockchain combines the following two ideas:
Design features
- Given some data, it is easy to calculate a checksum over the data. Special hash functions can be designed to calculate this checksum. These functions can be designed to return a value that always has the same length, which is not dependent on the length of the input. This value is called hash value, or message digest. The functions also have another property: Given the same input, they must return the same output (hash value/message digest).
- In addition to the hash values, a block typically also contains a timestamp, and some payload. Each block uses a digital signature[1], which allows detecting any change in the data since the signature was made. When new blocks of data are created, the newly created block will also contain the hash value of the previous block.[2]
In most cases, a blockchain is managed by a peer-to-peer network. All peers use a common protocol that specifies how they should communicate with each other, how a new block is created and validated. Once recorded, the data in any given block cannot be changed easily any more. Changing the block means all the blocks after it need to be changed as well. Depending on the protocol, this will require a majority of the peers, or even all the peers, to agree.
Blockchains are secure by design. Blockchain technology is used where keeping a correct record is important. Use cases include medical records,[3][4] identity management,[5][6][7] food traceability,[8] and voting.[9]
Blockchain was invented by Stuart Haber and Scott Stornetta in 1991 as a means to assure the integrity of digital records. Haber and Stornetta launched the world's first commercial blockchain; Surety[10] in 1995.
In 2008, 'Satoshi Nakamoto' included as references 3 and 4 of Bitcoin[11] the two papers by Haber and Stornetta [12][13] to serve as the public transaction ledger of the cryptocurrency bitcoin.[14] Because of its blockchain, bitcoin became the first digital currency to solve the double-spending problem without the need of a trusted authority or central server. The bitcoin design has inspired other applications.[14][15]
Blockchain and privacy
At first sight, the indefinite recording of all transactions in a blockchain is appealing to control freaks. All major central banks announced the introduction of blockchain money until 2025 [16].
However, paradoxically it is the solution of the double spending problem which actually enables anonymity. It depends on the implementation of the additional information stored on the blockchain ("payload") and the way it is connected to the p2p network: if only the transactions are recorded then they become trustless, i.e. there is no need to know who transferred money to whom. If by design for every transaction a new virtual address is used, then anonymity can be achieved if implemented correctly. [17]
On the other hand, if the blockchain is designed to hold a bulk of private data (i.e. health records, product purchases, etc.), this amounts to a major privacy hazard.
References
- ↑ https://web.archive.org/web/20191016115436/https://www.ambiguousit.com/blockchain-security-is-blockchain-secure-enough-really
- ↑ Narayanan, Arvind; Bonneau, Joseph; Felten, Edward; Miller, Andrew; Goldfeder, Steven (2016). Bitcoin and cryptocurrency technologies: a comprehensive introduction. Princeton: Princeton University Press. ISBN 978-0-691-17169-2.
- ↑ https://web.archive.org/web/20161225051907/http://mcdonnell.mit.edu/blockchain_ehr.pdf
- ↑ https://web.archive.org/web/20170119053224/https://www.pubpub.org/pub/medrec%7Carchive-date=19 January 2017
- ↑ https://web.archive.org/web/20170119054131/https://www.americanbanker.com/news/how-blockchain-fits-into-the-future-of-digital-identity%7Carchive-date=19 January 2017
- ↑ https://web.archive.org/web/20170131185730/https://bitcoinmagazine.com/articles/microsoft-building-open-blockchain-based-identity-system-with-blockstack-consensys-1464968713/
- ↑ =https://web.archive.org/web/20170119054646/https://bitcoinmagazine.com/articles/department-of-homeland-security-awards-blockchain-tech-development-grants-for-identity-management-and-privacy-protection-1471551442/
- ↑ https://web.archive.org/web/20170826120651/https://www.cnbc.com/2017/08/22/ibm-nestle-unilever-walmart-blockchain-food-contamination.html
- ↑ https://web.archive.org/web/20180115001300/https://followmyvote.com/online-voting-technology/blockchain-technology/
- ↑ http://www.surety.com/
- ↑ https://bitcoin.org/bitcoin.pdf
- ↑ https://www.anf.es/pdf/Haber_Stornetta.pdf
- ↑ http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.71.4891&rep=rep1&type=pdf
- ↑ a b https://web.archive.org/web/20160703000844/http://www.economist.com/news/briefing/21677228-technology-behind-bitcoin-lets-people-who-do-not-know-or-trust-each-other-build-dependable
- ↑ https://web.archive.org/web/20160522034932/http://www.nytimes.com/2016/05/22/business/dealbook/crypto-ether-bitcoin-currency.html
- ↑ https://www.sparkasse.de/aktuelles/digitaler-euro.html (Ger)
- ↑ "Satoshi" did this with his own invention, Bitcoin: he accessed the p2p network only with Tor and created a new identity for each transaction. The many attempts at de-anonymizing "Satoshi" were all unsucessful to this day (2022)
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