What is cryptocurrency?

Cryptocurrency is a digital or virtual currency secured by cryptography and recorded on a decentralized distributed ledger — typically a blockchain — that operates without a central bank or government authority. Bitcoin, the first cryptocurrency, was created in 2009 by the pseudonymous Satoshi Nakamoto; Ethereum, the second most significant, introduced programmable smart contracts in 2015 and enabled the broader digital asset ecosystem including decentralized finance (DeFi) and NFTs. As cryptocurrency has grown into a multi-trillion-dollar asset class, it has attracted both institutional adoption and regulatory attention — with AML frameworks, sanctions regimes, and financial crime obligations now extending to cryptocurrency exchanges, custodians, and related businesses in most major jurisdictions.

How does cryptocurrency work?

Blockchain Technology and the Distributed Ledger

Every cryptocurrency transaction is recorded on a blockchain — a distributed ledger maintained by a network of nodes that each hold a complete copy of the transaction history. New transactions are grouped into blocks, cryptographically verified by network participants, and added to the chain in sequence. Because no single entity controls the ledger, the blockchain is resistant to tampering: altering a historical transaction would require re-mining every subsequent block across the majority of the network simultaneously. This immutability is the property that makes blockchain data valuable as forensic evidence — transactions on a public ledger cannot be altered, deleted, or backdated after the fact.

Cryptographic Security and Wallet Infrastructure

Cryptocurrency ownership is represented by cryptographic key pairs — a public key (the wallet address, visible to anyone) and a private key (the cryptographic secret that authorizes transactions). Sending cryptocurrency requires signing a transaction with the private key; receiving it requires only sharing the public key. Digital wallets — software or hardware applications that store and manage key pairs — are the interface through which cryptocurrency is sent, received, and stored. Custodial wallets, managed by crypto exchanges, hold private keys on users’ behalf. Non-custodial wallets give users direct control over their keys and, by extension, their funds. The distinction matters for compliance: custodial wallet providers are classified as virtual asset service providers (VASPs) and face AML obligations, while non-custodial wallets generally do not — though the regulatory treatment of self-hosted wallets continues to evolve.

Consensus Mechanisms: Proof of Work and Proof of Stake

Cryptocurrency networks use consensus mechanisms — algorithms that validate transactions and add new blocks to the blockchain without a central authority. Bitcoin uses Proof of Work: miners compete to solve computationally intensive mathematical problems using significant computing power, with the winner earning the right to add the next block and receive a block reward in newly created Bitcoin. Ethereum transitioned to Proof of Stake in September 2022: validators stake cryptocurrency as collateral and are selected to validate blocks proportionally to their stake, consuming significantly less energy than mining. The consensus mechanism determines the security model, energy profile, and decentralization characteristics of each cryptocurrency network.

How Cryptocurrency Transactions Work

A cryptocurrency transaction follows a consistent sequence: a user initiates a transfer from their digital wallet; the transaction is broadcast to network nodes; nodes validate the transaction against the blockchain history — confirming the sender holds sufficient balance and the transaction is properly signed; the transaction is included in the next block; the block is confirmed and appended to the chain; and the recipient’s wallet reflects the updated balance. Transaction fees — paid to validators or miners for processing — vary by network congestion and blockchain. Confirmation times range from seconds on high-throughput networks like Solana to minutes on Bitcoin, depending on block time and fee priority.

Types of cryptocurrency

Bitcoin (BTC) — The Original Cryptocurrency

Bitcoin was introduced in a 2008 whitepaper by Satoshi Nakamoto and launched in January 2009 as the first peer-to-peer electronic cash system. Bitcoin’s fixed supply — capped at 21 million coins — is a deliberate design choice that differentiates it from fiat currency, which central banks can issue without a hard limit. Bitcoin is the largest cryptocurrency by market capitalization and the most widely held by institutional investors, including through spot Bitcoin ETFs approved by the SEC in January 2024, which extended institutional custody and transaction monitoring obligations to traditional asset managers operating in the digital asset space. In financial crime and compliance contexts, Bitcoin is the most traced cryptocurrency — its transparent UTXO transaction model and the maturity of blockchain analytics make forensic investigation highly effective.

Ethereum (ETH) — Programmable Blockchain

Ethereum introduced programmable smart contracts in 2015, enabling developers to build decentralized applications and DeFi protocols on the Ethereum blockchain. Ether (ETH) is the native digital currency used to pay for transaction execution on the network. Ethereum’s ecosystem is the largest in decentralized finance, NFTs, and tokenized digital assets. From a compliance perspective, Ethereum’s smart contract infrastructure underpins some of the most complex financial crime typologies — including Tornado Cash, a smart contract-based mixing protocol sanctioned by OFAC in August 2022 for facilitating the laundering of over $7 billion in cryptocurrency. The Tornado Cash designation established a landmark precedent: autonomous code on a public blockchain can itself be designated as a sanctions target under U.S. law, regardless of whether a human operator is identifiable.

Stablecoins

Stablecoins are cryptocurrencies designed to maintain a stable value, typically pegged to a fiat currency such as the U.S. dollar. They serve as the primary medium of exchange in DeFi protocols and as a mechanism for transferring value without exposure to cryptocurrency price volatility. The largest stablecoins — Tether (USDT) and USD Coin (USDC) — collectively represent hundreds of billions in circulating supply, with annual stablecoin transaction volume exceeding $4 trillion. Stablecoins issued by centralized entities can freeze accounts and reverse transactions under law enforcement direction; those governed solely by smart contracts cannot. Under FATF guidance, stablecoin issuers may qualify as VASPs with corresponding AML obligations, and the U.S. GENIUS Act signed in July 2025 established a federal regulatory framework for payment stablecoins for the first time.

Altcoins

Altcoins — alternative cryptocurrencies to Bitcoin — encompass thousands of digital assets with varying purposes, architectures, and market capitalizations. Well-known cryptocurrencies in this category include XRP (designed for institutional cross-border payments by Ripple), Solana (a high-throughput blockchain favored for DeFi and NFT applications), Cardano (ADA), Litecoin, and Dogecoin. From a compliance perspective, altcoins vary significantly in traceability: most popular cryptocurrencies on public blockchains are as traceable as Bitcoin. Privacy coins such as Monero, however, use cryptographic techniques including ring signatures and stealth addresses to obscure transaction details on-chain. OFAC has listed Monero-linked addresses on the SDN List, and multiple cryptocurrency exchanges have delisted privacy coins under regulatory pressure.

How does cryptocurrency have value?

Cryptocurrency derives value from three primary drivers: scarcity and supply constraints, network utility and adoption, and market sentiment. Bitcoin’s hard cap of 21 million coins is the canonical example of programmatic scarcity — no central bank can expand its supply. Ethereum’s value is tied to demand for its smart contract ecosystem, where ether is required to execute transactions and run decentralized applications. Speculative demand and market sentiment — amplified by social media, institutional announcements, and regulatory developments — drive short-term cryptocurrency prices.

The cryptocurrency market is characterized by extreme volatility relative to traditional asset classes, with significant price fluctuations driven by regulatory developments, macroeconomic conditions, and sentiment cycles. This volatility creates both investment risk and compliance risk: rapid price movements affect the fiat valuation of seized cryptocurrency in law enforcement operations and the practical impact of sanctions designations targeting specific digital currency addresses.

Cryptocurrency, financial crime, and compliance

Why Cryptocurrency Is Used in Financial Crime — and Why It’s Traceable

The pseudonymous nature of cryptocurrency transactions — wallet addresses are visible on the public ledger but not inherently linked to real identities — has made crypto attractive to illicit actors for money laundering, ransomware payments, sanctions evasion, and darknet market commerce. However, the same property that makes cryptocurrency pseudonymous — the permanent, immutable public record on the blockchain — makes it fundamentally more traceable than cash. Every transaction is permanently recorded, cannot be altered, and is visible to anyone with access to a blockchain node. Blockchain analytics platforms attribute wallet addresses to real-world entities through clustering heuristics, exchange intelligence, and law enforcement data sharing — producing the forensic trail that has supported billions of dollars in asset seizures and thousands of criminal prosecutions globally. The misconception that cryptocurrency enables untraceable financial crime is one of the most consequential errors in policy discussions today.

AML and KYC Obligations for Cryptocurrency Businesses

Cryptocurrency exchanges, custodians, wallet providers, and other VASPs are required under FATF Recommendation 15 and national implementing regulations to maintain AML programs equivalent to those of traditional financial institutions — including KYC verification at onboarding, ongoing transaction monitoring, sanctions screening, and suspicious activity report (SAR) filing. In the United States, crypto exchanges must register with FinCEN as Money Services Businesses and comply with Bank Secrecy Act requirements. In the EU, MiCA has extended comprehensive financial regulation to crypto-asset service providers. The regulatory landscape is global, rapidly evolving, and increasingly stringent — with record SAR filing volumes reflecting the growing scale of compliance obligations across the financial system.

Cryptocurrency Scams and Fraud

Cryptocurrency scams represent a significant and growing category of financial crime. Major fraud typologies include investment scams and pig butchering operations — long-duration social engineering schemes that manipulate victims into transferring cryptocurrency to fraudulent platforms — as well as rug pulls (developers abandoning projects after raising funds), phishing attacks targeting wallet credentials, pump-and-dump schemes inflated by social media hype, and fake crypto exchange platforms. Scam proceeds flow through legitimate cryptocurrency exchanges as criminals attempt to convert illicit funds to fiat currency, creating transaction monitoring obligations for the VASPs that process those flows. The Chainalysis Crypto Crime Report provides the authoritative annual data on cryptocurrency fraud volumes and evolving typologies.

Sanctions and Cryptocurrency

U.S., EU, and UN sanctions extend to cryptocurrency. OFAC maintains a virtual currency address section on the Specially Designated Nationals (SDN) List — designating specific Bitcoin, Ethereum, and other blockchain addresses associated with sanctioned individuals, entities, and programs including North Korea’s Lazarus Group, Russian ransomware operators, and Tornado Cash. For VASPs and financial institutions processing cryptocurrency transactions, sanctions compliance requires real-time wallet address screening against OFAC designations — not just name-based screening of account holders. This is a fundamental difference from traditional financial services sanctions programs and requires blockchain-native screening infrastructure.

Cryptocurrency is legal to own and trade in most major economies, though the regulatory framework governing its use as a payment method, investment asset, or commodity varies by jurisdiction. Some jurisdictions have established comprehensive crypto frameworks — the EU’s MiCA regulation, Singapore’s Payment Services Act, and the UAE’s Virtual Asset Regulatory Authority provide clear licensing and compliance requirements. In the United States, multiple agencies — including the SEC, CFTC, FinCEN, and OCC — claim jurisdiction across different digital asset classifications, creating a complex regulatory environment that continues to evolve. China maintains a prohibition on cryptocurrency trading and mining.

Critically, legality of ownership differs from regulatory compliance obligations: cryptocurrency may be legal to hold, but businesses that facilitate its exchange or custody face AML, KYC, sanctions, and tax reporting obligations in virtually every jurisdiction. The compliance question is not whether cryptocurrency is legal — it is whether the organization operating in the cryptocurrency ecosystem has built the program infrastructure that regulators expect.

Cryptocurrency vs. traditional currency

Understanding how cryptocurrency differs from traditional fiat currency is essential for compliance officers, regulators, and financial institutions assessing their digital asset exposure.

Dimension Traditional Currency (Fiat) Cryptocurrency
Issuance Central banks and governments Algorithmic or protocol-governed; no central issuer
Supply Discretionary; expanded by monetary policy Often fixed or programmatically constrained (Bitcoin: 21M cap)
Settlement Hours to days (SWIFT, ACH, card networks) Minutes to seconds (varies by network)
Custody Banks and financial institutions hold deposits Self-custody possible; custodial options available via exchanges
Traceability Bank records and correspondent banking data — private institutional records Public blockchain record — permanently visible to anyone with node access
AML Obligations BSA, AMLD, FATF Recommendation 10 FATF Recommendation 15; same framework, new implementation layer
Volatility Managed by central bank monetary policy Market-determined; historically high price fluctuations

The comparison highlights a key structural difference for compliance and law enforcement: while traditional currency flows through intermediaries that maintain private transaction records, cryptocurrency transactions are recorded on a public, immutable blockchain — making them visible to regulators, law enforcement, and compliance teams equipped with the right analytical tools. This transparency is not a vulnerability of the cryptocurrency ecosystem. It is the foundation of enforcement.

How Chainalysis helps organizations navigate the cryptocurrency ecosystem

The permanent transparency of the blockchain transforms cryptocurrency from a compliance challenge into an investigative and intelligence asset — but only with the right infrastructure. Chainalysis provides the data, software, and training that government agencies, financial institutions, and crypto businesses rely on to investigate, monitor, and stay compliant across the cryptocurrency ecosystem.

Chainalysis Reactor: Investigation and intelligence platform for tracing cryptocurrency transactions across 400+ blockchain networks, used by law enforcement agencies in over 100 countries to follow fund flows, attribute wallets, and build cases that hold up to Daubert-standard evidentiary scrutiny.

Chainalysis KYT (Know Your Transaction): Real-time transaction monitoring for exchanges and VASPs, enabling risk-based alerting that reduces false positives and meets FATF compliance obligations across the full blockchain transaction history.

Chainalysis Address Screening: Pre-transaction counterparty risk assessment, screening wallet addresses against sanctions lists, known illicit entities, and risk indicators before transactions are processed.

Chainalysis Academy: Free training in cryptocurrency fundamentals, blockchain forensics, and financial crime investigation, with over 50,000 professionals certified globally.

Frequently asked questions about cryptocurrency

Q: What is cryptocurrency in simple terms?

A: Cryptocurrency is digital money that uses cryptography for security and runs on a decentralized network called a blockchain, rather than being issued or controlled by a central bank or government. Bitcoin, created in 2009, was the first cryptocurrency; thousands now exist, including Ethereum, stablecoins like USDT and USDC, and altcoins such as XRP and Solana.

Q: How does cryptocurrency work?

A: Cryptocurrency works by recording transactions on a blockchain — a distributed digital ledger maintained by a network of computers (nodes) rather than a single institution. When you send cryptocurrency, the transaction is broadcast to the network, validated by nodes using a consensus mechanism such as Proof of Work or Proof of Stake, and permanently added to the blockchain. Ownership is controlled through cryptographic key pairs stored in digital wallets.

A: The most popular cryptocurrencies by market capitalization include Bitcoin (BTC), the original and largest cryptocurrency; Ethereum (ETH), which powers smart contracts and decentralized finance; stablecoins such as Tether (USDT) and USD Coin (USDC), pegged to the U.S. dollar; and altcoins including XRP, Solana, Cardano, Litecoin, and Dogecoin.

A: Cryptocurrency is legal to own and trade in most major economies, including the United States, the EU, the UK, and Singapore. However, businesses that facilitate cryptocurrency exchange or custody — such as crypto exchanges and wallet providers — must comply with AML, KYC, and sanctions obligations under local financial regulations. A small number of jurisdictions, including China, restrict or prohibit cryptocurrency trading.

Q: How does cryptocurrency differ from traditional currency?

A: Traditional currency (fiat) is issued by central banks, held by financial institutions, and transferred through intermediaries such as banks and payment networks. Cryptocurrency is issued algorithmically, can be self-custodied, and is transferred peer-to-peer on a public blockchain without intermediaries. The key structural difference for compliance and law enforcement is traceability: cryptocurrency transactions are permanently recorded on a public ledger, while traditional currency flows through private institutional records.

Q: What kinds of scams are connected to cryptocurrency?

A: Common cryptocurrency scams include investment scams and pig butchering operations, rug pulls, phishing attacks targeting wallet credentials, pump-and-dump schemes promoted via social media, and fake exchange platforms. The pseudonymous nature of cryptocurrency can initially mask scam operators, but blockchain analytics enable investigators to trace stolen funds and identify the exchanges where scam proceeds are cashed out.

Q: Can cryptocurrency transactions be traced?

A: Yes. Despite the common misconception that cryptocurrency is anonymous, transactions on public blockchains like Bitcoin and Ethereum are permanently recorded and visible to anyone. Blockchain analytics platforms trace fund flows across networks, attribute wallet addresses to real-world entities, and produce forensic evidence that supports law enforcement investigations, asset seizures, and criminal prosecutions. Cryptocurrency is, in practice, more traceable than cash — which is why blockchain analytics has become essential infrastructure for compliance teams and investigators operating in the digital asset ecosystem.

Cryptocurrency is the fastest-growing area of both financial innovation and financial crime.

Chainalysis gives law enforcement, financial institutions, and crypto businesses the tools to understand, investigate, and stay compliant in a market that moves faster than any other.

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