A visual guide to how bitcoin transactions work and rely on cryptography

A definitive guide to crypto and blockchain

The concept of cryptocurrency emerged more than a decade ago, with a famous whitepaper on bitcoin. To fully understand the rise of bitcoin, Bloomberg’s Matt Levine developed this comprehensive four-part series exploring the broader crypto and blockchain ecosystems, where they came from and how they work (subscription required).

Bitcoin explained and made simple

Bitcoin, the most popular and well-known example of a cryptocurrency, came on the scene around 2010, with its evangelists proclaiming it would eventually displace government-backed traditional cash. While the concept of a digital currency may seem straightforward, the details can be deceptively simple. This quick video overview provides the foundation for a deeper dive into the world of decentralized currency.

A simple visual explanation of how blockchains work

Blockchains are decentralized, distributed, and digital methods to record transactions and prevent alterations and tampering of the record. That's a simplified definition. This easy-to-understand six-minute video further and better explains what blockchains are and how they work using colorful illustrations and clear, concise clarifications on their processes and what makes them so special.

A look at nodes and miners in managing bitcoin transactions

Each time a transaction involving bitcoin is carried out, the information must be relayed and recorded onto the currency’s blockchain. Multiple steps are involved, including the passage of the transaction to various nodes and miners who comprise multiple layers of verification and validation. See an illustrated guide to how these two crucial features of bitcoin processing work here.

Watch an expert explain blockchain technology to five different people: a child, a teen, a college student, a grad student, and a fellow expert.

Using cryptocurrency to turn traditional financial arrangements on their head

Cryptocurrency is poised to drastically change everything in the financial world, including financial arrangements. Decentralized finance makes it easier for virtually anyone to take advantage of financial markets without the need for a bank. However, there are new risks involved as well. Professor of Legal Studies and Business Ethics Kevin Werbach, an expert on Bitcoin and blockchains discusses it all in detail in The Conversation.

The benefits of cryptocurrency and blockchain technology

At the root of cryptocurrencies' allure is blockchain technology, an innovation bringing profound transformations to industries, especially the financial industry. This simple article breaks down the difference between cryptocurrencies and blockchain as well as the benefits of each.

See how the concept of verification and addition to the blockchain works in real time.

Every transaction made via bitcoin is recorded on its blockchain—the decentralized, distributed ledger that provides a permanent and transparent record of the currency's entire history. While that may sound abstract, the technology allows anyone to monitor and confirm each of the transactions.

What is blockchain? A visual explanation from a Stanford professor

Stanford professor Dan Boneh teaches "Blockchain Primitives: Cryptography and Consensus," providing an introduction to the cryptographic foundation of blockchains and how developers can use them to build new types of applications.

Cryptocurrencies are forms of digital currency

Cryptocurrency's key feature is decentralization. Unlike traditional money, they generally aren't controlled by a single authority. As of early 2025, cryptocurrencies had a cumulative market cap of almost $3.4T, making them worth more than some of the world's most valuable companies, like Google and Amazon (both valued at roughly $2.3T).

Visualize how passkeys, which rely on asymmetric cryptography to authenticate users, work

After using biometrics or a PIN to access the private key stored on a device, it is combined with a random number generated by the site to produce a cryptographic signature. This signature is verified using the site's public key, allowing a user to log in without entering a password. This reduces the risk of fraudulent messages—phishing attacks—and data breaches.

Bitcoin, the oldest and most popular cryptocurrency, is a digital cash alternative introduced in 2009 that rapidly grew in popularity and now boasts a global user base.

The blockchain offers tantalizing possibilities for future use

Think of blockchains as a running list of information, where new details are added to the running chain as discrete "blocks." With crypto, the information contained within each block could be virtually anything, providing flexibility for uses in commerce, legal filings, healthcare records, and more.

Bitcoin and ethereum are decentralized cryptocurrencies with different functions

Bitcoin, launched in 2009, is primarily a digital currency and store of value with a fixed supply. Ethereum, introduced in 2015, enables smart contracts and decentralized apps, offering more flexibility.

Many bitcoin enthusiasts have compared the cryptocurrency to digital gold

Gold is valued for its stability and reliability, serving as a hedge against inflation and economic uncertainty. Bitcoin shares both of these characteristics, but also provides near-instant liquidity and isn’t subject to government regulation.

Cryptocurrency acts as a store of value

Traditional money, dating back to its first known uses in ancient Babylonia, has many uses—it reduces friction in transactions by providing a common denominator of value (unit of account), acts as a single item accepted by many vendors (medium of exchange), and holds wealth as a store of value.

The industries ripe for disruption by blockchain and cryptocurrencies

Blockchain—what is it good for? Lots of things, it would seem. Peruse this guide from The Motley Fool site and learn about different applications and use cases for blockchain technology. Financial exchanges, real estate, insurance, voting, an gambling are just a few of the 15 applications discussed here.

Crypto's origins date back to 1983

While crypto feels new, it actually dates to 1983, with eCash's creation. However, a lot has happened in the crypto world over the past few years in particular—crypto's market cap surpassed $2T for the first time in 2021, for instance. A timeline of crypto's history details the events in between.

Princeton University offers a free online bitcoin course

Want to understand bitcoin and cryptocurrencies? A free online course from Princeton University unpacks the details of bitcoin, from how it works to what distinguishes it from other currencies, to the security and anonymity associated with its use. Explore explainer videos, or take the course as a series of lessons.

Crypto exchanges are online platforms to buy, sell, and exchange cryptocurrencies

Crypto exchanges have grown alongside and fueled the boom in digital currencies. Popular exchanges like Coinbase, Kraken, and Binance each have separate features, fee structures, and more. You can learn how to begin with the platforms, how to carry out research, and when to be aware of the associated risks.

The science of cryptography, including methods to encrypt data and how to break encryption

Monoalphabetic ciphers use a set of rules to replace each letter with another consistently, making them susceptible to brute force attacks that try every kind of replacement. While more complex ciphers can transform text in less obvious ways, because certain letters are used more often than others, an analysis of letter frequency may reveal patterns that help uncover the rules that make up a cipher.

What are smart contracts?

Smart contracts are potentially one of the most useful tools associated with blockchain, and they can enable the transfer of everything from Bitcoin and fiat currency to goods transported around the world. Here’s what they do and why they’re likely to gain traction.

Lack of regulation makes cryptocurrency a hotbed for money laundering.

Why cryptocurrency matters from Andreesen Horowitz general partner

In this hourlong video, Andreessen Horowitz (a16z) General Partner Chris Dixon discusses "Crypto Networks and Why They Matter," giving an overview of the cryptocurrency space, the transformative implications of its technology, and the potential for cryptocurrency networks to lead a new wave of innovation.

Understanding the Diffie-Hellman key exchange, an example of public key cryptography

Published in 1976 by Whitfield Diffie and Martin Hellman, the system involves two parties combining each of their unique private keys with a public key using a mathematical function. The combinations are exchanged and mixed to establish a common key that no third party can determine. The Diffie-Hellman system underlies many encryption protocols for internet traffic.

Who accepts bitcoin payments in 2025?

Bitcoin and other cryptocurrencies are used primarily as stores of value or speculative assets, and less likely to be used to purchase goods and services. Advocates for the currency say as an increasing number of retailers accept bitcoin, average holders will begin to treat the currency more like traditional money.

Proof-of-work is the original way cryptocurrencies added new blocks to blockchains

It’s a competitive method requiring “miners” to solve cryptographic puzzles, often using equipment that consumes massive amounts of energy. Ethereum switched to proof-of-stake, a less energy-intensive method in which “validators” stake crypto to be randomly chosen to check transactions.

Only 21 million bitcoin will ever be created—what happens then?

Bitcoin is a popular cryptocurrency with a finite supply, and the issuance of new bitcoins is currently offered as a reward for verifying the transactions on the blockchain. Experts say the currency won't reach its limit until the year 2140, and miners may ultimately rely on transaction fees.

Check the real-time price of bitcoin

Bitcoin has gone through several boom and bust cycles. Those peaks and valleys sit on top of a steadily rising value, growing as the currency gains wider adoption. As of 2024, bitcoin’s total market value was over $1.3T, with more than 19.6 million coins in circulation. Still, the value fluctuates.

The role stories play in mass economic trends like bitcoin, crashes

Economics is dominated by numbers, but stories play a huge role in the emotional shifts seen within macroeconomic trends. For example, bitcoin is not just a cost-benefit winner, but a compelling tale of decentralization and independence. This is a 20-minute summary of Nobel prize-winning economist Robert Shiller's "Narrative Economics."

The future of the internet

Blockchain? Crypto? NFTs? Oh my. Gilles DC provides a simple breakdown of what Web3 is, what it involves, its connection with web currencies, and how you can begin your own explorations of this brave new world. Gilles promises to describe Web3 in one take, explain how the reader can take advantage of it, and how blockchain might build a better society as a result.

Watch a video that visualizes what really happens inside a credit card network when you make a purchase.

Create your own cipher by combining mathematical operations and encryption protocols

This tool allows users to build an encryption workflow in which the output of one customizable function becomes the input to another, thereby creating undiscovered methods for obscuring information via a series of ciphers.

Some venture capitalists believe cryptocurrency will revolutionize global finance

Some of the brightest minds at Andreesen-Horowitz, one of the country’s leading venture capital firms, believe the cryptocurrency ecosystem will revolutionize global finance in the coming decades. This podcast recounts, through their view, the history of crypto, how it works, and trends they see emerging in the future.

Read the original white paper from Satoshi Nakamoto

Satoshi Nakamoto's original introductory paper "Bitcoin: A Peer-to-Peer Electronic Cash System," is required reading for anyone who wishes to understand the cryptocurrency. Bitcoin.org provides assorted translations. While Nakamoto's identity remains a mystery, his ideas are neatly laid out here, along with supporting documentation.

Learn about Web3 and how it differs from past versions of the internet

Web3 is the idea of a new, decentralized internet built on blockchain technology. It aims to shift control from centralized entities like big tech companies to users through distributed ledgers and smart contracts. Key components include cryptocurrencies, NFTs, and decentralized autonomous organizations (DAOs) that operate without a central authority. Web3 promises more user privacy, ownership, and control over data and digital assets.

Visualizing the history of money

Money is any medium of exchange used in payments for goods or services and can take many forms. From cattle and shells in ancient times to paper and blockchain today, money has taken many shapes and sizes. This infographic illustrates some of the major forms of exchange world cultures have used over the last 5,000 years.

An explanation of Turing machines—the foundations of digital algorithms and computers

The device reads data, overwrites or ignores it, and then moves on to the next piece of data based on a set of programmed rules. By imagining this data as zeros and ones—binary that makes up computer code—Turing machines became the theoretical models for how any algorithm could be run on a computer if the procedure could be coded into a set of digital rules.

Ethereum is a blockchain-powered platform for building decentralized software and apps

Among crypto enthusiasts, ethereum is known for the cryptocurrency it uses to facilitate transactions: ether, or ETH. It's often compared to an app store. The underpinnings of ethereum's blockchain include dApps, which operate using automated scripts called "smart contracts."

The similarities and differences between bitcoin and ethereum

Ethereum is the second-largest cryptocurrency by market cap behind Bitcoin. Usually, that comparison just scratches the surface of the overall market cap. Instead, a visual pits the tokens up against each other on a per-token basis and shows how and why the Ethereum/bitcoin ratio has fluctuated over time.

Bitcoin's founder has always remained anonymous

A pseudonym used by the person or group of people who created bitcoin—the first decentralized cryptocurrency—the real identity of Satoshi Nakamoto has baffled millions of enthusiasts for years.

Ethereum is a blockchain-powered operating system known for its cryptocurrency, ether

Ethereum's underlying blockchain allows developers to build decentralized applications (dApps) that leverage smart contracts to seamlessly run decentralized financial tools (crypto wallets, exchanges, marketplaces, and more), along with Web3 concepts like non-fungible tokens.

A mathematical breakdown of how RSA encryption uses prime numbers to encrypt data

This form of asymmetric cryptography uses mathematical functions that rely on the product of two large prime numbers. Because traditional computers struggle to factor such products, obtaining the private keys needed to decrypt messages becomes effectively impossible. This security can be reinforced with larger prime numbers, though this makes encryption more computationally taxing.

Bitcoin started as a .PDF

Have you ever wondered how bitcoin became, well, bitcoin? In this podcast episode, journalist PJ Vogt dives into what drove the bitcoin hype machine, explaining how it became the phenomenon it is today.

A look at historical ciphers, from the Spartan 'scytale' to the Navajo Code Talkers

From the Greek word for "hidden writing," cryptography in Ancient Greece took the form of batons around which a long strip of leather or parchment was wrapped, after which messages were written. Recipients needed a scytale of the correct width to encircle received ribbons and reveal the message. Members of the Navajo Nation created a code that remained unbroken throughout its use in World War II.

Two Papa John's pizzas were the first real-world transaction involving cryptocurrency.

How end-to-end encryption protects messages, even from service providers

Using symmetric and asymmetric cryptography, data is encrypted on the sender's device before being transmitted across application servers that lack the key needed to decrypt it. The message is not decrypted until it reaches the recipient's device, which uses their private key to recover the plaintext. E2EE's effectiveness has led to its adoption by WhatsApp and Signal.

The 10 most important (other) cryptocurrencies

Bitcoin has not only been a trendsetter, ushering in a wave of cryptocurrencies built on a decentralized peer-to-peer network, but has also become the de facto standard for cryptocurrencies. But it's not the only one. Here are some cryptocurrencies that have held on throughout steep price climbs and nosedives.

The cryptocurrency equivalent of going public

An initial coin offering (ICO) is cryptocurrency's version of an initial public offering (IPO). Similar to the way a company offers shares on the stock market for the first time, ICOs occur when a cryptocurrency company seeks to raise funding for a new coin, app, or service. If you're entering the field, get the details on how it all works.

Bitcoin mining validates/adds bitcoin transactions onto the blockchain

Mining, done by a decentralized network of actors, is incredibly energy intensive, making the award of bitcoins a major incentive.