Ken Mueller

Ken Mueller

1643149440

Cestodial vs non-Custodial NFTs in Blockchain | Mis vahet sellel on

Selles postituses arutleme selle üle, mis vahe on plokiahelas ja defis kinnipidamisel ja mittevahistamisõigusega NFT-del.

Mitteasendatavate žetoonide (NFT) järele on suur nõudlus kogu plokiahela ja DeFi ökosüsteemides. NFT teema kohta on juba palju teavet, kuid me ei aruta sageli hooldusõigust. Kellel on tegelikult täielik kontroll teie äsja loodud või ostetud NFT üle? Võib juhtuda, et teil on oma NFT-d vähem kui arvate.

See kontseptsioon võib olla tuttav, kui olete juba rahakotte ja krüptorahasid uurinud. Tegelikult on teie NFT eestkostmine või kellegi teise käes hoidmine mõlemad sobivad võimalused. Kõik sõltub sellest, mida te otsite ja millist vastutust soovite kanda.

Peamised viisid, kuidas vangistusliku ja mittevahistamisõigusega NFT-dega kokku puutute, on rahakoti ja NFT-de kauplemiseks või loomiseks kasutatavate platvormide valimine.

Mis on krüptorahakott?

Krüptorahakott on oluline tööriist krüptovaluutade hoidmiseks ja plokiahelatega suhtlemiseks. Kui soovite teha tehinguid ja kasutada detsentraliseeritud rakendusi (DApps) , on teil vaja rahakotti. Igal rahakotil on kaks peamist aspekti: avalik võti ja privaatvõti. 

Teie rahakoti avalikku võtit kasutatakse aadresside genereerimiseks, millele teie või teised saavad krüptosõnumeid saata. Teie privaatvõti, mida peaksite käsitlema kui konfidentsiaalset parooli, allkirjastab tehingud ja annab juurdepääsu teie rahalistele vahenditele. Krüptorahakoti valimisel on palju valikuid. Võtmed saab printida paberile, pääseda juurde lauaarvuti rahakotitarkvara kaudu või sisalduda riistvaralistes rahakotiseadmetes.

Krüptorahakotid ei pea ka ainult krüptovaluutasid hoidma. Sõltuvalt teie rahakotist saate salvestada ka NFT-sid. Tõenäoliselt olete kasutanud krüptorahakotti digitaalsete varade (nt Bitcoin (BTC), eeter (ETH) või stabiilsete müntide saatmiseks või vastuvõtmiseks. Kuid mõned krüptorahakotid võivad salvestada ja edastada ka NFT-sid, mis on plokiahelas välja antud märgid.

Mis on vangistuslik krüptorahakott?

Isikukaitsega krüptorahakott ei anna teile täielikku kontrolli oma privaatvõtmete üle. Kolmas osapool (nt vahetus- või rahakotiteenuse pakkuja) salvestab teie vara teie eest. Te ei pääse oma privaatvõtmele ise juurde, kuid see ei pruugi olla halb. Kõik sõltub teie vajadustest.

Plokiahela tehnoloogia detsentraliseerimise tõttu võite oma privaatvõtme valesti paigutamisel jäädavalt kaotada juurdepääsu oma rahakotile. Kui teil on oma privaatvõtme hoidja, saate vastutuse neile edasi anda. Isegi kui unustate oma vahetusparooli, saate tõenäoliselt klienditoe abiga oma kontole tagasi pääseda.

Kuid ärge unustage, et sel juhul on teie rahaliste vahendite haldaja kolmas osapool. Teie krüpto on ainult nii turvaline, kuivõrd haldur seda hoiab. Seetõttu on oluline valida usaldusväärne vahetus- või teenusepakkuja.

Mis on vabadusekaotuseta krüptorahakott?

Vangistuseta krüptorahakott on rahakott, mille privaatvõtmeid omab ja kontrollib ainult omanik. Kasutajatele, kes soovivad oma raha üle suuremat kontrolli saada, on parim valik mittevahistamisõigusega rahakotid.

Kuid nagu eelnevalt mainitud, on vastutus võtme turvalisena hoidmise eest rahakotiomaniku kätes. Kui nad kaotavad võtmed ja ei mäleta oma varukoopiat, lähevad rahakott ja selle raha kaotsi. Rakendustena, täitmisfailidena ja brauserilaiendustena on saadaval mitu vabadusekaotuseta rahakotti. Populaarsed näited hõlmavad Trust Wallet ja MetaMask . Samuti võite leida rahakotiteenuseid (nt Tor.us), mis võimaldavad kasutajatel kasutada oma võtmete kaitsmiseks sotsiaalseid sisselogimisi, muutes protsessi turvalisemaks ja mugavamaks.

Milliseid rahakotte saan NFT-dega kasutada?

Krüptokunsti või muude NFT-de salvestamiseks saate kasutada nii vangistuslikku kui ka mittevahistamisõigusega rahakotti. Siiski veenduge, et teie kasutatav rahakott toetaks seda tüüpi NFT-d, mida soovite hoida. NFT-d võivad eksisteerida erinevatel plokiahelatel ja isegi üksikutel plokiahelatel võivad olla mitmesugused märgistandardid. Igal standardil on erinevad omadused ja reeglid, mis määravad žetoonide loomise ja kasutamise.

Kõige tavalisemad märgistandardid on:

Ethereum: ERC-721, ERC-1155

Binance Smart Chain: BEP-721, BEP-1155

Kui kavatsete hoida NFT-d kas kinnises rahakotis (nagu krüptovaluutabörsil) või rahakotis, mis ei ole kinnipeetav, kontrollige esmalt NFT-i märgistandardit. Selle teabe abil veenduge, et teie rahakott toetab teie digitaalse kunsti plokiahela ja märgi standardit.

MetaMask, Trust Wallet ja MathWallet on kõik rahakotid, mis ei ole kinnipeetavad, mis aktsepteerivad kõige levinumaid NFT-sid, millega tõenäoliselt kokku puutute. Kuid tsentraliseeritud börsiga suhtlemisel kasutate vangistuslikku rahakotti. Parim võimalus on vaadata oma börsi KKK-d või veebisaiti, et saada üksikasjalikumat teavet NFT-de kohta, mida nad aktsepteerivad.

Kuidas osta rahakotiga NFT-d?

NFT kogumisobjektide ostmine sõltub kahest asjast: rahakoti tüübist ja turust, mida soovite kasutada. Kui soovite oma NFT-ostu üle täielikult kontrollida ja soovite seda hoida rahakotis, mis ei ole kinnipeetav, peate kasutama detsentraliseeritud platvormi, näiteks Featured by Binance.

Detsentraliseeritud platvormid (mitte vangistusega)

Kui olete varem Binance DEX-i või mõnda muud detsentraliseeritud börsi kasutanud, võite olla juba tuttav mittevahistamissüsteemiga. Detsentraliseeritud vahetus ei nõua konto loomist ega registreerumist. Samuti tegelete tehingutega tavaliselt otse kummagi osapoole rahakoti vahel.

NFT turuplatsid (vahikaitse)

NFT turg toimib ostuprotsessi ajal haldurina. Kui soovite oksjonil pakkumist teha, peate saatma oma raha platvormile, et hoida neid tingdeponeerimisel. Kui olete oma NFT-i ostnud, võite seda hoida oma rahakotis või võtta selle teise rahakotti.

Binance NFT Marketplace nõuab ka NFT-de ostmiseks ja pakkumiste tegemiseks raha ülekandmist nende rahakotti. Teie Binance'i konto peab olema krüptoga "laaditud", kuna veebisait ei suhtle otseselt välise rahakotiga.

Kuidas rahakoti abil NFT-d vermida või müüa?

Detsentraliseeritud platvormid (mitte vangistusega)

NFT loomise protsessi nimetatakse vermimiseks. NFT vermimiseks peate ühendama oma rahakoti ja laadima oma digitaalsed varad üles NFT platvormile, näiteks Featured by Binance. Seal saate üles laadida pilte, heli- või videofaile koos metaandmetega (oma NFT-de kirjeldamiseks). Teil on võimalus luua üksikuid NFT-sid või kogumit, mis koosneb NFT-de rühmast.

Pärast vermimist salvestatakse teie varad ahelasse ja neid ei saa muuta. Soovi korral võite oma NFT-d müüki panna. Binance pakub praegu oma järelturul kahte müügimeetodit: fikseeritud hinnaga müüki ja ingliskeelset oksjonit.

Niipea kui müük on lõppenud, jagatakse teie NFT-d ostjatele. Müügist saadav tulu laekub ostjate rahakotist teie rahakotti. Protsess on automatiseeritud ja turvatud nutikate lepingute reeglitega.

NFT turuplatsid (vahikaitse)

NFT müümiseks arestiturul peate selle hoiule kandma kasutatavale platvormile. Veenduge, et platvorm aktsepteerib seda tüüpi NFT-d, mida soovite müüa. Kui te pole siin ettevaatlik, võite oma NFT-d kergesti kaotada, kui saadate need ühildumatule platvormile. Igal turul on erinevad müügivõimalused, näiteks fikseeritud hinnaga müük või oksjon.

Kui olete oma NFT edukalt müünud, annab turg selle automaatselt üle uuele omanikule. Teie raha saadetakse otse teie välisesse rahakotti või jäetakse platvormile, kus saate välja võtta.

Eestkostetava NFT-teenuse plussid ja miinused

Vangistusteenus pakub lihtsat viisi NFT ostjate ja müüjate leidmiseks, mida uustulnukatel on lihtne kasutada. Pole vaja muretseda võtme kaotamise pärast, mis on kergendus isegi kogenumatele kasutajatele. Liidesed on üldiselt kasutajasõbralikud ja vigade tegemisel on kogu protsess andestavam. Probleemi ilmnemisel peaks platvormil olema abi.

Kuid paljude krüptoentusiastide jaoks, kes hindavad detsentraliseerimist, on oma varade otsene kontrollimata jätmine tohutu puudus. KYC-tšekid on standardsed ka mõnede kinnipidamisasutuste NFT-teenuste puhul, mis nõuavad teie nime, aadressi ja ID-d. Kui teie andmed on salvestatud, on alati oht, et need võidakse varastada või rikkuda. Samuti pole teadmata, et kinnipidamisteenuste häkkimine toimub.

Vangistusvaba NFT-teenuse plussid ja miinused

Vangistusvabad NFT-platvormid pakuvad palju suuremat kontrolli kogu tehinguprotsessi vältel. NFT-dega kauplemine otse oma rahakotist ilma vahendajata pakub odavamaid tasusid ja suuremat privaatsust. Need tegurid sõltuvad aga rohkem kasutatavast võrgust. Kui hindate privaatsust, pole KYC-tšekke vaja, et saaksite kaubelda anonüümselt. Kõik, mida vajate, on alustamiseks rahakott.

Vangistusevälisel kontrollil on mõned varjuküljed. Uute kasutajate jaoks, kes pole rahakotiga nii kursis, võivad mittevahistamisvõimalused olla vähem kasutajasõbralikud ja mugavad kui vahistamisõigusega valikud. Õnneks muudavad teenusepakkujad nagu Tor.us dappide kasutamise palju lihtsamaks.

Alates 2021. aasta juunist on mittehoiustamispõhiste börside likviidsus ja maht tavaliselt madalam kui deposiitilistel börsidel – välja arvatud suurtel mängijatel, nagu Uniswap. Kuid mis puudutab NFT-sid, siis on see tööstus veel väga varajases staadiumis, mistõttu on seda raske mõõta. Likviidsus sõltub siiski kasutajaskonnast ja kauplemismahust ning on suur võimalus, et depooteenustega mitteseotud teenused kasvavad lähitulevikus välja. Samuti on projekte, mis töötavad platvormidevahelistel, mittehoiustamisõigusega turgudel, mis tõenäoliselt hoiavad ära likviidsusprobleemid.

Vangistuslikud ja mittevahistamisõigusega NFTd lühidalt

 NFT hooldusteenusVangistuseta NFT-teenus
PrivaatvõtiKolmanda osapoole omandRahakoti omaniku omand
JuurdepääsetavusRegistreeritud kontodJuurdepääs kõigile
TehingukuludTavaliselt kõrgemTavaliselt madalam
TurvalisusTavaliselt madalamTavaliselt kõrgem
ToetusTavaliselt kõrgemTavaliselt madalam
võtiJahEi

Olenevalt sellest, mida otsite, on oma eelised nii vangistuslikul kui ka mittevabadusel. Vangistuseta NFT-platvorm, nagu Featured By Binance , on suurepärane valik kõigile, kes hindavad autonoomiat ja turvalisust.

☞  REGISTREERU BINANCE'IS

Vähem kogenud kasutajate jaoks võib olla mõttekam kasutada NFT turgu ja rahakotti. Hooldusteenused võimaldavad teil kulutada rohkem aega suhtlemisele ja vähem aega rahakotis navigeerimise õppimiseks. Sel juhul on Binance NFT Marketplace suurepärane võimalus kaaluda.

Täname, et lugesite!

What is GEEK

Buddha Community

Devin Pinto

1606217442

Blockchain Certification | Blockchain Training Course | Blockchain Council

In all the market sectors, Blockchain technology has contributed to the redesign. The improvements that were once impossible have been pushed forward. Blockchain is one of the leading innovations with the ability to influence the various sectors of the industry. It also has the ability to be one of the career-influencing innovations at the same time. We have seen an increasing inclination towards the certification of the Blockchain in recent years, and there are obvious reasons behind it. Blockchain has everything to offer, from good packages to its universal application and futuristic development. Let’s address the reasons why one should go for Blockchain certification.

5 advantages of certification by Blockchain:

1. Lucrative packages- Everyone who completes their education or upskills themselves wants to end up with a good bundle, not only is one assured of a good learning experience with Blockchain, but the packages are drool-worthy at the same time. A Blockchain developer’s average salary varies between $150,000 and $175,000 per annum. Comparatively, a software developer gets a $137,000 per year salary. For a Blockchain developer, the San Francisco Bay area provides the highest bundle, amounting to $162,288 per annum. There’s no point arguing that learning about Blockchain is a smart decision with such lucrative packages.

2. Growing industry- When you select any qualification course, it becomes important that you choose a growing segment or industry that promises potential in the future. You should anticipate all of these with Blockchain. The size of the blockchain market is expected to rise from USD 3.0 billion in 2020 to USD 39.7 billion by 2025. This will see an incredible 67.3 percent CAGR between 2020-2025. To help business processes, several businesses are outsourcing Blockchain technologies. This clearly demonstrates that there will be higher demand in the future for Blockchain developers and certified Blockchain professionals.

3. Universal application- One of the major reasons for the success of Blockchain is that it has a global application. It is not sector-specific. Blockchain usage cases are discovered by almost all market segments. In addition, other innovations such as AI, big data, data science and much more are also supported by Blockchain. It becomes easier to get into a suitable industry once you know about Blockchain.

**4. Work protection-**Surely you would like to invest in an ability that ensures job security. You had the same chance for Blockchain. Since this is the technology of the future, understanding that Blockchain can keep up with futuristic developments will help in a successful and safe job.

**5.**After a certain point of your professional life, you are expected to learn about new abilities that can help enhance your skills. Upskilling is paramount. Upskilling oneself has become the need for the hour, and choosing a path that holds a lot of potential for the future is the best way to do this. For all computer geeks and others who want to gain awareness of emerging technology, Blockchain is a good option.

Concluding thoughts- opting for Blockchain certification is a successful career move with all these advantages. You will be able to find yourself in a safe and secured work profile once you have all the knowledge and information. Link for Blockchain certification programme with the Blockchain Council.

#blockchain certificate #blockchain training #blockchain certification #blockchain developers #blockchain #blockchain council

Winona Aufderhar

Winona Aufderhar

1598265735

5 Blockchain Applications That Have Transformed the World of Technology

The blockchain is the decentralized database of the blocks of information, which gets recorded in the chain format and linked in a secured crypto graphical manner. This technology ensures proper safety of the data due to its secure nature, and it totally changes how people carry out transactions. It also brings about a faster and secure process of validating information needed to establish reliability.

Though blockchain technology came into the market to carry out only digital transactions, it is now used in various industries like supply chain, finance, health care, and many more.

The blockchain technology has made its position in mobile app development as well. Blockchain applications are transparent and accountable. From getting easy access to medical records and buying insurance, you can see blockchain applications everywhere.

Here are some of the areas where you can see the use of blockchain applications and how they have changed various industries.

1. Ripple

Ripple is useful for increasing banking transactions. The implementation of blockchain technology in the financial sector is much more profound than any other sector. Ripple proves this. It is one of the greatest tools to record and complete financial transactions.

It develops a large network despite strict physical boundaries. As there is no such third-party involvement present, the cost of these transactions is lower than usual. At the same time, the network also remains transparent and quite secured.

It is normally seen that financial transactions that happen globally are

error-prone and take a lot of time. In addition to this, when the transaction

fees and exchange rates get added up, the total cost usually gets high.

However, Ripple offers real-time international transactions without spending too much money. It has the network of about 200+ institutions making the process affordable, secure, and fast for all sorts of international transactions.

2. Etherisc

This blockchain application helps in automating flight insurance. Insurance is another area where blockchain is gaining popularity. Through this application, insurers can make smart contracts rather than getting involved in the traditional contracts that are usually complex. Etherisc is the blockchain application that helps customers buy flight insurance. If the flight gets canceled or delayed, they do not have to wait for months to get the payment back. This application ensures an on-time payout.

#blockchain #blockchain-technology #blockchain-development #blockchain-use-cases #blockchain-a #blockchain-technologies #technology #decentralization

Devin Pinto

1622187022

Tangle vs Blockchain: Difference Between Tangle & Blockchain

Cryptocurrency is a digital medium of exchange that uses encryption to send and receive money. The most frequently utilised cryptocurrency for which Blockchain technology was created is Bitcoin. Despite the fact that Blockchain has been the standard cryptocurrency technology for the past few years, concerns about speed and scalability have led to the creation of other solutions.

Tangle is a relatively young cryptocurrency. In this essay, we’ll look at the latest dispute between Tangle and Blockchain to see which is the better option.

What is Blockchain?
Blockchain is a transaction ledger that is cryptographically secure. Bitcoin, Litecoin, and Ethereum, as well as other cryptocurrencies, are all accepted. The ledger is made up of transaction blocks that are cryptographically connected to each other. Each block is linked to the previous one, preserving the ledger’s whole history.

All of the machines involved in these transactions are known as nodes. Each node authenticates transactions independently. This means that after both nodes have confirmed a transaction, it can proceed.

Want to learn more about Blockchain Technology? Blockchain certification courses could be the best to get started with.

What is Tangle?
Tangle is a bitcoin transaction technology that works in a similar fashion to Blockchain. Here, a directed acyclic graph (DAG) is used, which is similar to a distributed ledger. DAG is not governed by any external entity, such as a bank or a financial organisation.

Tangle is IoT-friendly, which is the cherry on top (Internet of Things). The Internet of Things (IoT) is a network of interconnected devices that can exchange data and communicate with each other. Tangle will be able to conduct large-scale transactions between multiple linked devices swiftly and seamlessly as a result of this.

What are the differences between a tangle and a blockchain?

Structure — A blockchain is made up of a lengthy, ever-growing chain of nodes, or data blocks, each one linked to the one before it. A tangle, on the other hand, is made up of data nodes that all flow in the same direction. And, unlike blockchain, which may technically loop back on itself in a circular pattern, the tangle can only go in one direction at a time and cannot reverse. This enables speedier data transport.

Security – Due to its arduous block-formation process, which involves the solution of a mathematical problem and verification through group consensus, blockchain has a higher level of security. Before a device can complete its own transaction and thus create a data node, it must first validate two previous transactions. The tangle is less secure than blockchain due to this less robust procedure.

Decentralization — Both blockchain and the tangle are decentralised systems, which means they are free of outside meddling and the fees and hurdles that come with it. The tangle, however, has had to erect a safety net, which it refers to as a “coordinator node.” This node effectively puts a centralising aspect into the tangle’s structure, putting to rest claims that it allows for entirely independent, uninterrupted transactions between IoT units.

Wrapping up

In this case, blockchain has a clear advantage. It’s significantly more secure than Tangle and supports decentralised apps. Blockchain is becoming more popular among businesses and users for cryptocurrency transactions.

Tangle is still in its infancy and has faults. The technique can’t be labelled truly decentralised because it relies on a central coordinator node. This node checks that transactions are genuine, however Tangle data is not entirely self-contained in this regard. Because the node addition protocol is less precise than Blockchain, it is also less secure.

#blockchain technology #blockchain professionals #blockchain platform #blockchain platform #blockchain council

Devin Pinto

1620649756

Private Blockchain Vs Consortium Blockchain: What’s the difference?

Blockchain technology is a distributed, decentralised ledger that enables the registration of transactions, the tracking of properties, and the establishment of trust all without the involvement of a third party. There are three types of blockchain platforms available on the market for various reasons: public blockchains, proprietary blockchains, and consortium blockchains.

Regardless of the variants, all blockchains are networks of peers with append-only ledgers that agree on the correctness of transactions through a consensus mechanism.
Due to the rapid advancement of blockchain technology, the variety and job opportunities are virtually endless. If you want to jumpstart your career and pursue a career as a blockchain developer, you have a plethora of opportunities ahead of you. Learn blockchain for beginners online and then enter the illustrious world of blockchain growth.

**But first, let’s find out what Private and consortium blockchain mean

What is Private Blockchain?**
A private blockchain is a permissioned blockchain platform, while a public blockchain is permissionless, meaning that nobody can access the network and read, write, or communicate with the blockchain without permission. These blockchains are access-restricted, limiting the number of users who may enter the network. These blockchains are more suited to corporate use cases, where a business requires the benefits of blockchain technology without exposing its network to the public.

What is Consortium Blockchain?
Consortium blockchain, alternatively referred to as federated blockchain, is a type of blockchain technology that is controlled by a network of entities rather than a single one. It is not a public forum, nor is it password-protected. This type of blockchain is most advantageous when a large number of businesses operate in the same market and need a centralised network for conducting transactions or relaying data. Although it might seem that these blockchains are similar to private blockchains, they are not.

**Private Blockchain Vs. Consortium Blockchain

Decentralization**
Due to the fact that the blockchain infrastructure is controlled by a single entity, private blockchain creates a partly decentralised network that is governed by a set of laws and regulations.
On the other hand, though consortium blockchains are permissioned, they achieve true decentralisation because, unlike private blockchains, they enable multiple entities to make network-wide decisions.

Accessibility
Private blockchains are managed by a centralised body.
On the other hand, a consortium blockchain is managed by a group of individuals rather than a single individual. It is a password-protected forum that enables different businesses to collaborate on decisions.

Consensus Mechanism
In private blockchains, voting or multi-party consensus processes are used. Despite its reputation for resource conservation, it is insecure as compared to energy-intensive consensus algorithms such as Proof of Work.

Federated blockchains, on the other hand, achieve an agreement through the use of multi-part consensus algorithms or voting systems.

Handling Data in the Ledger
Since private blockchains are controlled centrally, they allow both read and write access to the ledger, meaning that once a transaction is registered, it cannot be altered. However, in this situation, only one authority has the ability to write or interpret any entries in the ledger.

Although no one has the ability to change any of the consortium blockchain’s database entries. Unlike a private blockchain, however, the ledger enables several individuals to write and read transactions.

Wrapping up
Each blockchain is a distinct technology that can be used in a variety of situations. Combining private and consortium blockchain platforms is straightforward since they both provide anonymity, protection, and rapid performance. Consortiums are ideal for organisations looking to streamline their networking, while private blockchains are better suited to a single entity.

#blockchain developer career #blockchain development #learn blockchain online #blockchain training #blockchain platform

Thandeka Abrahams

Thandeka Abrahams

1646737200

A Collection About Awesome Blockchains

Mining Digital Gold one Block at a Time?! • Don't Expect to Get Insanely Rich (Quick) • Tulips :tulip::tulip::tulip: (like Blockchains) are Great and Gorgeous (and will Endure)

b0 = Block.first(
        { from: "Dutchgrown", to: "Vincent", what: "Tulip Bloemendaal Sunset", qty: 10 },
        { from: "Keukenhof",  to: "Anne",    what: "Tulip Semper Augustus",    qty: 7  } )

b1 = Block.next( b0,
        { from: "Flowers",    to: "Ruben",   what: "Tulip Admiral van Eijck",  qty: 5  },
        { from: "Vicent",     to: "Anne",    what: "Tulip Bloemendaal Sunset", qty: 3  },
        { from: "Anne",       to: "Julia",   what: "Tulip Semper Augustus",    qty: 1  },
        { from: "Julia",      to: "Luuk",    what: "Tulip Semper Augustus",    qty: 1  } )
...

(Source: blockchain_with_transactions.rb)

Awesome Blockchains

A collection about awesome blockchains - open distributed databases w/ crypto hashes incl. git ;-). Blockchains are the new tulips :tulip::tulip::tulip:.

Contents:

What's News?

For blockchain books, see the new Best of Crypto Books page »

The Open Blockchains Book of the Year 2020 Award Goes To...

Libra Shrugged: How Facebook Tried to Take Over the Money by David Gerard, November 2020, 182 Pages -- Introduction: Taking over the money ++ A user's guide to Libra ++ The genesis of Libra: Beller's blockchain ++ To launch a Libra: Let’s start a crypto ++ Bitcoin: why Libra is like this ++ The Libra White Papers ++ Banking the unbanked ++ The Libra Reserve plan and economic stability ++ Libra, privacy and your digital identity ++ The regulators recoil in horror ++ David Marcus before the US House and Senate ++ July to September 2019: Libra runs the gauntlet ++ October 2019: Libra's bad month ++ Mark Zuckerberg before the US House ++ November 2019: The comedown ++ Central bank digital currencies ++ Epilogue: Libra 2.0: not dead yet ++ Appendix: 2010–2013: The rise and fall of Facebook Credits

For more about Diem (formerly Libra), see the Awesome Diem (formerly Libra) and Move page »

For crypto quotes, see the new 100+ Best of Crypto Quotes - I HODL, you HODL, we HODL! - BREAKING: BITCOIN JUST BROKE $22 000! page »

The Best Crypto Quote "Oracle Saying" of the Year 2020 Award Goes To...

SEC Investor Education:

  • Don't understand an investment?
  • Don't invest in it.

Yes, but what if there's only 21 million of it?

- Trolly McTrollface

Frequently Asked Questions (F.A.Q.s) & Answers

Q: What's a Blockchain?

A: A blockchain is a distributed database with a list (that is, chain) of records (that is, blocks) linked and secured by digital fingerprints (that is, cryptho hashes). Example from blockchain.rb:

[#<Block:0x1eed2a0
  @timestamp     = 1637-09-15 20:52:38,
  @data          = "Genesis",
  @previous_hash = "0000000000000000000000000000000000000000000000000000000000000000",
  @hash          = "edbd4e11e69bc399a9ccd8faaea44fb27410fe8e3023bb9462450a0a9c4caa1b">,
 #<Block:0x1eec9a0
  @timestamp     = 1637-09-15 21:02:38,
  @data          = "Transaction Data...",
  @previous_hash = "edbd4e11e69bc399a9ccd8faaea44fb27410fe8e3023bb9462450a0a9c4caa1b",
  @hash          = "eb8ecbf6d5870763ae246e37539d82e37052cb32f88bb8c59971f9978e437743">,
 #<Block:0x1eec838
  @timestamp     = 1637-09-15 21:12:38,
  @data          = "Transaction Data......",
  @previous_hash = "eb8ecbf6d5870763ae246e37539d82e37052cb32f88bb8c59971f9978e437743",
  @hash          = "be50017ee4bbcb33844b3dc2b7c4e476d46569b5df5762d14ceba9355f0a85f4">,
  ...

Q: What's a Hash? What's a (One-Way) Crypto(graphic) Hash Digest Checksum?

A: A hash e.g. eb8ecbf6d5870763ae246e37539d82e37052cb32f88bb8c59971f9978e437743 is a small digest checksum calculated with a one-way crypto(graphic) hash digest checksum function e.g. SHA256 (Secure Hash Algorithm 256 Bits) from the data. Example from blockchain.rb:

def calc_hash
  sha = Digest::SHA256.new
  sha.update( @timestamp.to_s + @previous_hash + @data )
  sha.hexdigest   ## returns "eb8ecbf6d5870763ae246e37539d82e37052cb32f88bb8c59971f9978e437743"
end

A blockchain uses

  • the block timestamp (e.g. 1637-09-15 20:52:38) and
  • the hash from the previous block (e.g. edbd4e11e69bc399a9ccd8faaea44fb27410fe8e3023bb9462450a0a9c4caa1b) and finally
  • the block data (e.g. Transaction Data...)

to calculate the new hash digest checksum, that is, the hash e.g. be50017ee4bbcb33844b3dc2b7c4e476d46569b5df5762d14ceba9355f0a85f4.

Q: What's a Merkle Tree?

A: A Merkle tree is a hash tree named after Ralph Merkle who patented the concept in 1979 (the patent expired in 2002). A hash tree is a generalization of hash lists or hash chains where every leaf node (in the tree) is labelled with a data block and every non-leaf node (in the tree) is labelled with the crypto(graphic) hash of the labels of its child nodes. For more see the Merkle tree Wikipedia Article.

Note: By adding crypto(graphic) hash functions you can "merkelize" any data structure.

Q: What's a Merkelized DAG (Directed Acyclic Graph)?

A: It's a blockchain secured by crypto(graphic) hashes that uses a directed acyclic graph data structure (instead of linear "classic" linked list).

Note: Git uses merkelized dag (directed acyclic graph)s for its blockchains.

Q: Is the Git Repo a Blockchain?

A: Yes, every branch in the git repo is a blockchain. The "classic" Satoshi-blockchain is like a git repo with a single master branch (only).

Do-It-Yourself (DIY) - Build Your Own Blockchain

Python • Ruby • JavaScript • Java • Go

Python

Let's Build the Tiniest Blockchain in Python Series by Gerald Nash

Build Your Own Blockchain: A Python Tutorial by Eric Munsing, March 2017, (Source)

Learn Blockchains by Building One (in Python) by Daniel van Flymen, September 2017, (Source) -- The fastest way to learn how Blockchains work is to build one

Build Your Own Blockchain (in Python 3) Series by Jack Schultz, (Source)

A Practical Introduction to Blockchain with Python by Adil Moujahid, March 2018, (Source)

Ruby

How Does Bitcoin Force Consensus Among Byzantine Generals? by Fabio Akita, November 2017

blockchain-lite - Build your own blockchains with crypto hashes; revolutionize the world with blockchains, blockchains, blockchains one block at a time! by Gerald Bauer, Ruby Advent Calendar 2017 / Day 1, December 2017

merkletree library - Build Your Own Crypto Hash Trees; Grow Your Own Money on Trees by Gerald Bauer, Ruby Advent Calendar 2017 / Day 19, December 2017

centralbank command line tool (and library) - Print Your Own Money / Cryptocurrency; Run Your Own Federated Central Bank Nodes on the Blockchain Peer-to-Peer over HTTP by Gerald Bauer, Ruby Advent Calendar 2017 / Day 24, December 2017

A guide to building a blockchain & cryptocurrency from scratch (Source) by Antoine Fink, April 2021

Crystal

Write your own blockchain and Proof-of-Work (PoW) algorithm using Crystal by Bradford Lamson-Scribner, May 2018, (Source)

JavaScript

Writing a Tiny Blockchain in JavaScript by Xavier Decuyper, July 2017

Node.js Blockchain Imlementation: BrewChain: Chain+WebSockets+HTTP Server by Darren Beck, November 2017, (Source) -- Protecting the tea making ledger from unscrupulous colleagues

Build your own Blockchain in Javascript/Visualization of Blockchains by Nam Chu Hoai, January 2018

TypeScript

Naivecoin: a tutorial for building a cryptocurrency by Lauri Hartikka, (Source)

Java

Creating Your First Blockchain with Java, Part 1 by Kass, December 2017, (Source)

Kotlin

Let's implement a cryptocurrency in Kotlin by Vasily Fomin, July 2018, (Source)

SQL

Blockchain by Example in SQL Server by Benjamin Campbell, December 2017, (Source)

Rust

Building Blockchain in Rust Series by Jacob Lindahl, GeekLaunch, (Source), (Slide Decks in PDF)

Go

Building Blockchain in Go Series by Ivan Kuznetsov, (Source)

Blockchain Series in Go by by Coral Health (Source)

Talk Notes

More

See Build your own Blockchain / Cryptocurrency @ Build your own (insert technology here)

Samples

Blockchain from Scratch - Ruby Version

class Block

  attr_reader :timestamp
  attr_reader :data
  attr_reader :previous_hash
  attr_reader :hash

  def initialize(data, previous_hash)
    @timestamp     = Time.now
    @data          = data
    @previous_hash = previous_hash
    @hash          = calc_hash
  end

  def self.first( data="Genesis" )    # create genesis (big bang! first) block
    ## note: uses all zero for previous_hash ("0")
    Block.new( data, "0000000000000000000000000000000000000000000000000000000000000000" )
  end

  def self.next( previous, data="Transaction Data..." )
    Block.new( data, previous.hash )
  end

private

  def calc_hash
    sha = Digest::SHA256.new
    sha.update( @timestamp.to_s + @previous_hash + @data )
    sha.hexdigest
  end

end  # class Block


#####
## let's get started
##   build a blockchain a block at a time

b0 = Block.first( "Genesis" )
b1 = Block.next( b0, "Transaction Data..." )
b2 = Block.next( b1, "Transaction Data......" )
b3 = Block.next( b2, "More Transaction Data..." )

blockchain = [b0, b1, b2, b3]

pp blockchain

(Source: blockchain.rb)

will pretty print (pp) something like:

[#<Block:0x1eed2a0
  @timestamp     = 1637-09-15 20:52:38,
  @data          = "Genesis",
  @previous_hash = "0000000000000000000000000000000000000000000000000000000000000000",
  @hash          = "edbd4e11e69bc399a9ccd8faaea44fb27410fe8e3023bb9462450a0a9c4caa1b">,
 #<Block:0x1eec9a0
  @timestamp     = 1637-09-15 21:02:38,
  @data          = "Transaction Data...",
  @previous_hash = "edbd4e11e69bc399a9ccd8faaea44fb27410fe8e3023bb9462450a0a9c4caa1b",
  @hash          = "eb8ecbf6d5870763ae246e37539d82e37052cb32f88bb8c59971f9978e437743">,
 #<Block:0x1eec838
  @timestamp     = 1637-09-15 21:12:38,
  @data          = "Transaction Data......",
  @previous_hash = "eb8ecbf6d5870763ae246e37539d82e37052cb32f88bb8c59971f9978e437743",
  @hash          = "be50017ee4bbcb33844b3dc2b7c4e476d46569b5df5762d14ceba9355f0a85f4">,
 #<Block:0x1eec6d0
  @timestamp     = 1637-09-15 21:22:38,
  @data          = "More Transaction Data...",
  @previous_hash = "be50017ee4bbcb33844b3dc2b7c4e476d46569b5df5762d14ceba9355f0a85f4",
  @hash          = "5ee2981606328abfe0c3b1171440f0df746c1e1f8b3b56c351727f7da7ae5d8d">]

Comments from the reddit ruby posting:

Wait, so a blockchain is just a linked list?

No. A linked list is only required to have a reference to the previous element, a block must have an identifier depending on the previous block's identifier, meaning that you cannot replace a block without recomputing every single block that comes after. In this implementation that happens as the previous digest is input in the calc_hash method.

What about Proof of Work / Waste?

Let's add a proof of work / waste to the blockchain. In the classic blockchain you have to compute a block hash that starts with leading zeros (00). The more leading zeros the harder (more difficult) to compute. Let's keep it easy to compute with two leading zeros (00), that is, 16^2 = 256 possibilites (^1,2). Three leading zeros (000) would be 16^3 = 4_096 possibilites and four zeros (0000) would be 16^4 = 65_536 and so on.

(^1): 16 possibilties because it's a hex or hexadecimal or base 16 number, that is, 0 1 2 3 4 6 7 8 9 a (10) b (11) c (12) d (13) e (14) f (15).

(^2): A random secure hash algorithm needs on average 256 tries (might be lets say 305 tries, for example, because it's NOT a perfect statistic distribution of possibilities).

Example:

def compute_hash_with_proof_of_work( difficulty="00" )
  nonce = 0
  loop do
    hash = calc_hash_with_nonce( nonce )
    if hash.start_with?( difficulty )  
      return [nonce,hash]     ## bingo! proof of work if hash starts with leading zeros (00)
    else
      nonce += 1              ## keep trying (and trying and trying)
    end
  end
end

def calc_hash_with_nonce( nonce=0 )
  sha = Digest::SHA256.new
  sha.update( nonce.to_s + @timestamp.to_s + @previous_hash + @data )
  sha.hexdigest
end

(Source: blockchain_with_proof_of_work.rb)

Let's rerun the sample with the proof of work machinery added. Now the sample will pretty print (pp) something like:

[#<Block:0x1e204f0
  @timestamp     = 1637-09-20 20:13:38,
  @data          = "Genesis",
  @previous_hash = "0000000000000000000000000000000000000000000000000000000000000000",
  @nonce         = 242,
  @hash          = "00b8e77e27378f9aa0afbcea3a2882bb62f6663771dee053364beb1887e18bcf">,
 #<Block:0x1e56e20
  @timestamp     = 1637-09-20 20:23:38,
  @data          = "Transaction Data...",
  @previous_hash = "00b8e77e27378f9aa0afbcea3a2882bb62f6663771dee053364beb1887e18bcf",
  @nonce         = 46,
  @hash          = "00aae8d2e9387e13c71b33f8cd205d336ac250d2828011f5970062912985a9af">,
 #<Block:0x1e2bd58
  @timestamp     = 1637-09-20 20:33:38,
  @data          = "Transaction Data......",
  @previous_hash = "00aae8d2e9387e13c71b33f8cd205d336ac250d2828011f5970062912985a9af",
  @nonce         = 350,
  @hash          = "00ea45e0f4683c3bec4364f349ee2b6816be0c9fd95cfd5ffcc6ed572c62f190">,
 #<Block:0x1fa8338
  @timestamp     = 1637-09-20 20:43:38,
  @data          = "More Transaction Data...",
  @previous_hash = "00ea45e0f4683c3bec4364f349ee2b6816be0c9fd95cfd5ffcc6ed572c62f190",
  @nonce         = 59,
  @hash          = "00436f0fca677652963e904ce4c624606a255946b921132d5b1f70f7d86c4ab8">]

See the difference? All hashes now start with leading zeros (00) and the nonce is the random "lucky number" that makes it happen. That's the magic behind the proof of work.

Blockchain from Scratch - JavaScript Version

class Block {

  constructor(data, previousHash) {
    this.timestamp    = new Date()
    this.data         = data
    this.previousHash = previousHash
    this.hash         = this.calcHash()
  }

  calcHash() {
    var sha = SHA256.create()
    sha.update( this.timestamp.toString() + this.previousHash + this.data )
    return sha.hex()
  }

  static first( data="Genesis" ) {    // create genesis (big bang! first) block
    // uses all-zero previousHash
    return new Block( data, "0000000000000000000000000000000000000000000000000000000000000000" )
  }

  static next( previous, data="Transaction Data..." ) {
    return new Block( data, previous.hash )
  }
}


//////
// let's get started
//   build a blockchain a block at a time

b0 = Block.first( "Genesis" )
b1 = Block.next( b0, "Transaction Data..." )
b2 = Block.next( b1, "Transaction Data......" )
b3 = Block.next( b2, "More Transaction Data..." )


blockchain = [b0, b1, b2, b3]

console.log( blockchain )

(Source: blockchain.js)

will log something like:

[ Block {
     timestamp    : 1637-09-18 08:25:54,
     data         : 'Genesis',
     previousHash : '0000000000000000000000000000000000000000000000000000000000000000',
     hash         : 'c396de4c03ddb5275661982adc75ce5fc5905d2a2457d1266c74436c1f3c50f1' },
   Block {
     timestamp    : 1637-09-18 08:35:54,
     data         : 'Transaction Data...',
     previousHash : 'c396de4c03ddb5275661982adc75ce5fc5905d2a2457d1266c74436c1f3c50f1',
     hash         : '493131e09c069645c82795c96e4715cea0f5558be514b5096d853a5b9899154a' },
   Block {
     timestamp    : 1637-09-18 08:45:54,
     data         : 'Transaction Data......',
     previousHash : '493131e09c069645c82795c96e4715cea0f5558be514b5096d853a5b9899154a',
     hash         : '97aa3cb5052615d60ff8e6b41bef606562588c4874f011970ac2f218e2f0f4a8' },
   Block {
     timestamp    : 1637-09-18 08:55:54,
     data         : 'More Transaction Data...',
     previousHash : '97aa3cb5052615d60ff8e6b41bef606562588c4874f011970ac2f218e2f0f4a8',
     hash         : 'e10e020f832e46c2b60e1c3c0412bd370b2fde5f0f782c16eb87d0313ea0d3a3' } ]

Blockchain Articles

Reflections on the Blockchain by Rufus Pollock (Open Knowledge Foundation), July 2016 -- The DAO: Code is not Law – and It’s Dangerous to Think So ++ The Internet changed the world - surely the Blockchain will too? ++ Gold-rush or Internet-rush? ++ Governance Matters in Bitcoin ++ The Myth of a Costless, Ownerless Network ++ Lessons from History

On the Dangers of a Blockchain Monoculture by Tony Arcieri, January 2016 -- The Bitcoin blockchain: the world's worst database ++ Next-generation protocols ++ Decentralized ledger protocols ++ Bitcoin-NG ++ Blockchain! Blockchain! Blockchain! ++ The great decentralized database in the sky

I Don’t Believe in Blockchain by Tim Bray, May 2017

Minimum Viable Blockchain by Ilya Grigorik, May 2014 -- Securing transactions with triple-entry bookkeeping ++ Securing transactions with PKI ++ Balance = Σ(receipts) ++ Multi-party transfers & verification ++ Double-spending and distributed consensus - Requirements for a distributed consensus network; Protecting the network from Sybil attacks; Proof-of-work as a participation requirement ++ Building the minimum viable blockchain - Adding "blocks" & transaction fee incentives; Racing to claim the transaction fees; Resolving chain conflicts; Blocks are never final ++ Properties of the (minimum viable) blockchain

Blockchains by analogies and applications: How blockchain compares to Git, Raft, and other technologies. by Kieren James-Lubin, January 2016 -- Blockchains are databases ++ Understanding transactions ++ Persistent, replicated databases (related technology: Git) ++ Peer-to-peer networks (related technology: BitTorrent) ++ Distributed consensus (related technology: distributed databases, Raft) ++ Minting new coins (mining) ++ Embedded identities (related technology: TLS) ++ Smart contracts: Like SQL expressions & triggers ++ What can we really do with blockchains?

Blockchain Books

Attack of the 50 Foot Blockchain: Bitcoin, Blockchain, Ethereum & Smart Contracts by David Gerard, London, 2017 -- What is a bitcoin? ++ The Bitcoin ideology ++ The incredible promises of Bitcoin! ++ Early Bitcoin: the rise to the first bubble ++ How Bitcoin mining centralised ++ Who is Satoshi Nakamoto? ++ Spending bitcoins in 2017 ++ Trading bitcoins in 2017: the second crypto bubble ++ Altcoins ++ Smart contracts, stupid humans ++ Business bafflegab, but on the Blockchain ++ Case study: Why you can’t put the music industry on a blockchain

Mastering Bitcoin - Programming the Open Blockchain 2nd Edition, by Andreas M. Antonopoulos, 2017 - FREE (Online Source Version) -- What Is Bitcoin? ++ How Bitcoin Works ++ Bitcoin Core: The Reference Implementation ++ Keys, Addresses ++ Wallets ++ Transactions ++ Advanced Transactions and Scripting ++ The Bitcoin Network ++ The Blockchain ++ Mining and Consensus ++ Bitcoin Security ++ Blockchain Applications

BEWARE: Bitcoin is a gigantic ponzi scheme¹. To the moon!? The new gold standard!? Do NOT "invest" trying to get-rich-quick HODLing. Why not? The bitcoin code is archaic and out-of-date. Burn, baby, burn! Proof-of-work / waste is a global energy environmental disaster using 300 kW/h per bitcoin transaction (!) that's about 179 kilograms of CO₂ emissions². Programmable money (or the internet of value) for all future generations with (bitcoin) script without loops and jumps (gotos) and all "stateless"!? LOL.

¹: (Source: Best of Bitcoin Maximalist - Scammers, Morons, Clowns, Shills & BagHODLers - Inside The New New Crypto Ponzi Economics)

²: Assuming let's say 0.596 kilograms of CO₂ per kW/h (that's the energy efficiency in Germany) that's about 179 kilograms of CO₂ per bitcoin transaction (300 kW/h × 0.596 kg). For more insights see the Bitcoin Energy Consumption Index.

Programming Bitcoin from Scratch by Jimmy Song, 2019 - FREE (Online Source Version) -- Chapter 6 - Script - How Script Works • Example Operations • Parsing the Script Fields • Combining the Script Fields • Standard Scripts • p2pk • Problems with p2pk • Solving the Problems with p2pkh • Scripts Can Be Arbitrarily Constructed • Conclusion ++ Chapter 8 - Pay-to-Script Hash - Bare Multisig • Coding OP_CHECKMULTISIG • Problems with Bare Multisig • Pay-to-Script-Hash (p2sh) • Coding p2sh • Conclusion ++ Chapter 13 - Segregated Witness - Pay-to-Witness-Pubkey-Hash (p2wpkh) • p2wpkh Transactions • p2sh-p2wpkh • Coding p2wpkh and p2sh-p2wpkh • Pay-to-Witness-Script-Hash (p2wsh) • p2sh-p2wsh • Coding p2wsh and p2sh-p2wsh • Other Improvements • Conclusion

Programming Bitcoin Script Transaction (Crypto) Contracts Step-by-Step ( Beta / Rough Draft ) by Gerald Bauer et al, 2019 - FREE (Online Version) -- Let's start with building your own bitcoin stack machine from zero / scratch and let's run your own bitcoin ops (operations)...

Programming Blockchains in Ruby from Scratch Step-by-Step Starting w/ Crypto Hashes... ( Beta / Rough Draft ) by Gerald Bauer et al, 2018 - FREE (Online Version) -- (Crypto) Hash ++ (Crypto) Block ++ (Crypto) Block with Proof-of-Work ++ Blockchain! Blockchain! Blockchain! ++ Blockchain Broken? ++ Timestamping ++ Mining, Mining, Mining - What's Your Hash Rate? ++ Bitcoin, Bitcoin, Bitcoin ++ (Crypto) Block with Transactions (Tx)

Mastering Ethereum - Building Contract Services and Decentralized Apps on the Blockchain - by Andreas M. Antonopoulos, Gavin Wood, 2018 - FREE (Online Source Version) What is Ethereum ++ Introduction ++ Ethereum Clients ++ Ethereum Testnets ++ Keys and Addresses ++ Wallets ++ Transactions ++ Contract Services ++ Tokens ++ Oracles ++ Accounting & Gas ++ EVM (Ethereum Virtual Machine) ++
Consensus ++
DevP2P (Peer-To-Peer) Protocol ++ Dev Tools and Frameworks ++ Decentralized Apps ++ Ethereum Standards (EIPs/ERCs)

Building Decentralized Apps on the Ethereum Blockchain by Roberto Infante, 2018 - FREE chapter 1 -- Understanding decentralized applications ++ The Ethereum blockchain ++ Building contract services in (JavaScript-like) Solidity ++ Running contract services on the Ethereum blockchain ++ Developing Ethereum Decentralized apps with Truffle ++ Best design and security practice

Programming Crypto Blockchain Contracts Step-by-Step Book / Guide ( Beta / Rough Draft ) by Gerald Bauer et al, 2019 - FREE (Online Version) -- Let's Start with Ponzi & Pyramid Schemes. Run Your Own Lotteries, Gambling Casinos and more on the Blockchain World Computer...

Programming Cryptocurrencies and Blockchains in Ruby ( Beta / Rough Draft ) by Gerald Bauer et al, 2018 - FREE (Online Version) @ Yuki & Moto Press Bookshelf -- Digital $$$ Alchemy - What's a Blockchain? - How-To Turn Digital Bits Into $$$ or €€€? • Decentralize Payments. Decentralize Transactions. Decentralize Blockchains. • The Proof of the Pudding is ... The Bitcoin (BTC) Blockchain(s) ++ Building Blockchains from Scratch - A Blockchain in Ruby in 20 Lines! A Blockchain is a Data Structure • What about Proof-of-Work? What about Consensus? • Find the Lucky Number - Nonce == Number Used Once ++ Adding Transactions - The World's Worst Database - Bitcoin Blockchain Mining • Tulips on the Blockchain! Adding Transactions ++ Blockchain Lite - Basic Blocks • Proof-of-Work Blocks • Transactions ++ Merkle Tree - Build Your Own Crypto Hash Trees; Grow Your Own Money on Trees • What's a Merkle Tree? • Transactions ++ Central Bank - Run Your Own Federated Central Bank Nodes on the Blockchain Peer-to-Peer over HTTP • Inside Mining - Printing Cryptos, Cryptos, Cryptos on the Blockchain ++ Awesome Crypto ++ Case Studies - Dutch Gulden • Shilling • CryptoKitties (and CryptoCopycats)

Blockchain for Dummies, IBM Limited Edition by Manav Gupta, 2017 - FREE (Digital Download w/ Email) -- Grasping Blockchain Fundamentals ++ Taking a Look at How Blockchain Works ++ Propelling Business with Blockchains ++ Blockchain in Action: Use Cases ++ Hyperledger, a Linux Foundation Project ++ Ten Steps to Your First Blockchain application

Get Rich Quick "Business Blockchain" Bible - The Secrets of Free Easy Money, 2018 - FREE -- Step 1: Sell hot air. How? ++ Step 2: Pump up your tokens. How? ++ Step 3: Revolutionize the World. How?

Best of Bitcoin Maximalist - Scammers, Morons, Clowns, Shills & BagHODLers - Inside The New New Crypto Ponzi Economics by Trolly McTrollface, et al, 2018 - FREE

Crypto Facts - Decentralize Payments - Efficient, Low Cost, Fair, Clean - True or False? by Nouriel Roubini, David Gerard, et al, 2018 - FREE

Crypto is the Mother of All Scams and (Now Busted) Bubbles - While Blockchain Is The Most Over-Hyped Technology Ever, No Better than a Spreadsheet/Database by Nouriel Roubini, 2018 - FREE

IslandCoin White Paper - A Pen and Paper Cash System - How to Run a Blockchain on a Deserted Island by Tal Kol -- Motivation ++ Consensus ++ Transaction and Block Specification - Transaction format • Block format • Genesis block ++ References

Blockchain (Lite) Crypto Hash Libraries

Ruby • JavaScript

Ruby

blockchain.lite (github: openblockchains/blockchain.lite.rb, gem: blockchain-lite) - build your own blockchain with crypto hashes - revolutionize the world with blockchains, blockchains, blockchains one block at a time

require 'blockchain-lite'

b0 = Block.first( "Genesis" )
b1 = Block.next( b0, "Transaction Data..." )
b2 = Block.next( b1, "Transaction Data......" )
b3 = Block.next( b2, "More Transaction Data..." )

blockchain = [b0, b1, b2, b3]

pp blockchain

will pretty print (pp) something like:

[#<Block:0x1eed2a0
  @timestamp     = 1637-09-15 20:52:38,
  @data          = "Genesis",
  @previous_hash = "0000000000000000000000000000000000000000000000000000000000000000",
  @hash          = "edbd4e11e69bc399a9ccd8faaea44fb27410fe8e3023bb9462450a0a9c4caa1b">,
 #<Block:0x1eec9a0
  @timestamp     = 1637-09-15 21:02:38,
  @data          = "Transaction Data...",
  @hash          = "eb8ecbf6d5870763ae246e37539d82e37052cb32f88bb8c59971f9978e437743",
  @previous_hash = "edbd4e11e69bc399a9ccd8faaea44fb27410fe8e3023bb9462450a0a9c4caa1b">,
  ...

JavaScript

blockchain.lite (github: openblockchains/blockchain.lite.js, npm: blockchain-lite) - build your own blockchain with crypto hashes - revolutionize the world with blockchains, blockchains, blockchains one block at a time

const Blocks = require( "blockchain-lite" )

// use basic block
let Block = Blocks.basic

let b0 = Block.first( 'Genesis' )
let b1 = Block.next( b0, 'Transaction Data...' )
let b2 = Block.next( b1, 'Transaction Data......' )
let b3 = Block.next( b2, 'More Transaction Data...' )

let blockchain = [b0, b1, b2, b3]

console.log( blockchain )

will log something like:

[ Block {
    timestamp:     2017-09-25 17:03:38,
    data:         'Genesis',
    previousHash: '0000000000000000000000000000000000000000000000000000000000000000',
    hash:         '08f4fa71628c5bc6b430228738bc8c41afaf508ece0b1cf9c9cac53d02e11829' },
  Block {
    timestamp:     2017-09-25 17:13:38,
    data:         'Transaction Data...',
    previousHash: '08f4fa71628c5bc6b430228738bc8c41afaf508ece0b1cf9c9cac53d02e11829',
    hash:         '740a4aeb3441484c96d1e7f63d31b716220ccee3b6fe94547cae2afbb6010626' },
  Block {
    timestamp:     2017-09-25 17:23:38,
    data:         'Transaction Data......',
    previousHash: '740a4aeb3441484c96d1e7f63d31b716220ccee3b6fe94547cae2afbb6010626',
    hash:         '28b6892a069e2ff7f1c3128ab495d7cd9b9b1636a51a7f69db93a14b1ee6b1a7' },
  Block {
    timestamp:     2017-09-25 17:33:38,
    data:         'More Transaction Data...',
    previousHash: '28b6892a069e2ff7f1c3128ab495d7cd9b9b1636a51a7f69db93a14b1ee6b1a7',
    hash:         '4cc0329b2c0cb32e0451fa3179bd944d4cd0fcf410939172f979e9fd2aa9f5f3' } ]

Git, Git, Git - The Stupid Content Tracker with Crypto Hashes

Everything is local. Distributed is the new centralized.

Quotes - Blockchains and Git

Yep, that's the joke. Nobody has been able to explain to me how the "blockchain" buzzword is significantly different to "git repo". -- Yaakov

But if you said "let's build a currency where all transactions are stored in a git repo" you wouldn't be taken seriously for even 24 hrs. -- Yaakov

Soon explaining git like "a git repo is like a blockchain with commits instead of blocks". -- Nicolás Berger

"A local branch is like a state channel. It can be pushed and merged into the master blockchain at any moment." -- Nicolás Berger

The #Blockchain has changed the world. Here I make the argument that the #Blockchain is just like #git. -- Jackson Kelley

git merge [-m REF] [-g BLOB] --push Merge and push all signed commits to the blockchain. -- Git Commands

Books

Learn Enough Git to Be Dangerous by Michael Hartl - FREE (Online Version) -- Getting started ++ Backing up and sharing ++ Intermediate workflow ++ Collaborating ++ Conclusion ++ Advanced setup

Pro Git by Scott Chacon and Ben Straub, 2nd Edition, 2014 - FREE (Online Version) -- Getting Started ++ Git Basics ++ Git Branching ++ Git on the Server ++ Distributed Git ++ GitHub ++ Git Tools ++ Customizing Git ++ Git and Other Systems ++ Git Internals ++ A1: Git in Other Environments ++ A2: Embedding Git in your Applications ++ A3: Git Commands

Git gets easier once you get the basic idea that branches are homeomorphic endofunctors mapping submanifolds of a Hilbert space. -- Anonymous

Open Distributed Databases on Git

football.db - open public domain football datasets (incl. clubs, national teams, leagues, match schedules, etc.)

world.db - open public domain world (country) datasets

beer.db - open public domain beer & brewery datasets

Add a beer transaction to the #blockchain on #git and win a free Wiener Lager beer! Cheers. Prost. -- Gerald Bauer @ Austria Codes

Open Distributed (Hyper) Ledger Books on Git

Shilling (or Schilling) - Shilling on the Blockchain! - Rock-Solid Alpine Dollar from Austria

Tulips - Tulips on the Blockchain! - Learn by Example from the Real World (Anno 1637) - Buy! Sell! Hold! Enjoy the Beauty of Admiral of Admirals, Semper Augustus, and More

Classic Tulip Mania

A period in the Dutch Golden Age during which contract prices for bulbs of the recently introduced tulip reached extraordinarily high levels and then dramatically collapsed in February 1637.

Quotes - Blockchains are the next Internets / Tulips

People who compare digital tokens to tulips are essentially saying digital tokens are a bubble backed by nothing but pure hype and speculation.

What they fail to understand is that tulips come from dirt, not a blockchain.

And as we all know, blockchain is possibly the best technological innovation since the internet. It will have a tremendous impact on global business and society in general. -- TulipToken

Books

Tulipomania: The Story of the World's Most Coveted Flower & the Extraordinary Passions It Aroused by Mike Dash, 2001 -- A Mania for Tulips ++ The Valley of Tien Shan ++ Within the Abode of Bliss ++ Stranger from the East ++ Clusius ++ Leiden ++ An Adornment to the Cleavage ++ The Tulip in the Mirror ++ Florists ++ Boom ++ At the Sign of the Golden Grape ++ The Orphans of Wouter Winkel ++ Bust ++ Goddess of Whores ++ At the Court of the Tulip King ++ Late Flowering

Tulipmania: Money, Honor, and Knowledge in the Dutch Golden Age by Anne Goldgar, 2007 -- Something Strange ++ Art & Flowers ++ Bloemisten ++ Grieving Money ++ Bad Faith ++ Cabbage Fever ++ Glossary ++ A Note on Money

Breaking News: CryptoKitties (Yes, Cute Little Cartoon Cats) on the Blockchain!

Collectible. Breedable. Adorable.

Collect and breed digital cats. Start meow. Buy! Sell! Hold!

Learn more @ cryptokitties.co

Latest (and Greatest) Investment Opportunity!

Blockchain has unlocked the magic of digital scarcity, and combining that with the power of making the digital goods persistent gives them a potential value that is only limited by how much prestige a wealthy person might place on ownership of the item.

-- Justin Poirier‏

All I want for Christmas is a CryptoKitty.

-- Kayla Williams

I got a fever. And the only prescription is more CryptoKitties.

-- Eduardo Salazar

My Gen 7 CryptoKitty #104375. The Future is Meow.

-- Anshul Dhawan

  • Fabulous Persian Spock Gerbil Gold Cottoncandy - Extremely rare gen 5 swift virgin | 2.9 ETH
  • Rarity: 0.00264% Gen 5 JAGUAR FABULOUS GOLD DALI!! VIRGIN!
  • Rarity: 0.0015% Princess Bubblegum is now for sale! Gen 12 | Brisk | Virgin | Chartreux | Bubblegum | Otaku | Emeraldgreen | Saycheese | Mauveover | Spock - Starts ETH 20/Ends ETH 10
  • Gold ducat, Gen 5, Virgin, Swift. Very cheap
  • Cheap Gen 1 cute kittie with rare genes! Only 0.125 ETH
  • UNIQUE Virgin Peach Googly Gold Mauveover gen:2 cooldown:1 0.87992% RARE
  • SUPER CHEAP: Gerbil, Ragdoll, Scarlet, Chestnut, Cotton Candy!!! 0.02 ETH (~$14)
  • I'm giving away a Gen 1 FAST Gold for free...

-- CrypoKittiesMarket

Awesome CryptoKitties (and CryptoCopycats)

A collection about Awesome CryptoKitties (Yes, Cute Little Cartoon Cats) on the Blockchain! and CryptoCopycats - digital collectibles secured on a distributed public databases w/ crypto hashes. Are CryptoPuppies the new CryptoKitties? Learn by Example from the Real World (Anno 2017) - Buy! Sell! Hodl!

More @ cryptocopycats/awesome-cryptokitties

Events, Meetups, Orgs

Revolutionize the world one country at a time. Blockchainers of the world, unite!

Awesome Awesomeness

A curated list of awesome lists.

  • Blockchain Stuff -- a curated list of blockchain and general cryptocurrency resources
  • Awesome Blockchain by Igor Barinov et al -- a curated list of the bitcoin blockchain services
  • Awesome Blockchain by Tim Reznich et al -- a curated list of blockchain services and exchanges
  • Awesome Blockchain by istinspring et al -- a curated list of awesome projects and services based on blockchain technology
  • Awesome Coins by Kenneth Reitz et al -- a guide to crypto-currencies and their algos
  • Awesome CryptoKitties (and CryptoCopycats) by Gerald Bauer et al -- a curated list about the awesome crypto kitties and copycats
  • Awesome Git by Dick Tang et al -- a curated list of amazingly awesome Git tools, resources and shiny things
  • Awesome by Sindre Sorhus et al -- a curated list of awesome lists

Author: openblockchains
Source Code: https://github.com/openblockchains/awesome-blockchains
License: CC0-1.0 License

#blockchain