D igital currency Revision Notes

Digital currency is money that exists only in electronic form; it has no physical counterpart such as coins or banknotes. Unlike traditional cash, digital currency is stored, transferred, and managed using computer systems and networks. This means it can be sent instantly across the internet without the need for physical exchange.

Because it is purely digital, digital currency relies on secure electronic systems to verify ownership and transactions. This distinguishes it from physical money, which can be held and exchanged directly by individuals.

• Exists only electronically, no physical form.
• Stored and transferred via computer networks.
• Relies on electronic verification of ownership.

There are several forms of digital currency, but two main categories are widely recognised: cryptocurrencies and digital wallets.

Cryptocurrencies, such as Bitcoin and Ethereum, use cryptographic techniques to secure transactions and control the creation of new units. They operate on decentralised networks called blockchains, which record all transactions in a secure and transparent way.

Digital wallets are software applications that store digital currency and allow users to make payments or transfers online. These wallets can hold cryptocurrencies or digital versions of traditional currencies issued by banks or governments, often called e-money or central bank digital currencies (CBDCs).

• Cryptocurrencies use blockchain technology and cryptography.
• Digital wallets store and manage digital currency for users.
• Some digital currencies are issued by governments (CBDCs).

Digital currency is primarily used for online transactions, enabling users to buy goods and services over the internet quickly and securely. It also facilitates peer-to-peer transfers without intermediaries like banks, reducing transaction fees and processing times.

Beyond purchases, digital currency is used for investment purposes, where people buy and hold cryptocurrencies hoping their value will increase. It is also used for remittances, allowing workers to send money internationally with lower costs compared to traditional methods.

Businesses increasingly accept digital currency payments, and some governments explore issuing their own digital currencies to improve payment efficiency and financial inclusion.

• Used for online purchases and payments.
• Enables peer-to-peer money transfers.
• Supports investment and remittance services.
• Adopted by businesses and governments.

Digital currency offers several benefits over traditional money. Transactions can be faster and cheaper because they often bypass banks and other intermediaries. Digital currency can be accessed globally, making cross-border payments simpler.

It also provides greater convenience, as users can pay using mobile devices or computers without carrying physical cash. Some digital currencies offer enhanced security through cryptographic protections, reducing risks of fraud and counterfeiting.

Additionally, digital currencies can increase financial inclusion by providing access to financial services for people without bank accounts, especially in remote or underserved areas.

• Faster and cheaper transactions.
• Global accessibility and convenience.
• Enhanced security features.
• Promotes financial inclusion.

Despite its advantages, digital currency faces challenges. Its value can be highly volatile, especially cryptocurrencies, which may fluctuate widely in short periods, posing risks for users and investors.

Security concerns remain, such as hacking of digital wallets or exchanges. Users must protect private keys and use secure platforms to prevent theft.

Regulatory uncertainty exists because governments are still developing laws to govern digital currencies, which can affect their acceptance and legal status. Privacy issues also arise since some digital currencies record transactions publicly on blockchains, potentially exposing user data if not managed properly.

• Price volatility, especially in cryptocurrencies.
• Security risks like hacking and theft.
• Regulatory and legal uncertainties.
• Privacy concerns with transaction transparency.

Blockchain is a technology that acts as a digital ledger, recording transactions electronically. Unlike traditional ledgers kept by a single authority, blockchain is decentralized, meaning copies of the ledger exist on many computers simultaneously. This decentralization helps prevent tampering or loss of data.

Each entry in the blockchain is called a block. These blocks contain details of transactions, such as the amount of digital currency transferred, the sender, the receiver, and a time-stamp showing when the transaction occurred. Blocks are linked together in a chronological order, forming a chain — hence the name blockchain.

• Blockchain is a digital ledger distributed across multiple computers.
• It records transactions in blocks linked sequentially.
• Each block contains transaction details and a time-stamp.

When a digital currency transaction occurs, it is grouped with other transactions into a block. This block is then added to the existing chain of blocks. Each new block contains a unique code called a cryptographic hash, which is generated based on the contents of the block and the hash of the previous block. This linking ensures that if any information in a previous block is changed, the hash will no longer match, making tampering evident.

Because the blockchain is stored on many computers (nodes), altering one copy would require changing all copies simultaneously, which is practically impossible. This makes the blockchain an unchangeable, or immutable, record of transactions.

• Transactions are grouped into blocks before being added to the chain.
• Each block contains a cryptographic hash linking it to the previous block.
• Altering a block breaks the chain’s integrity and is easily detected.
• Decentralized storage across many computers prevents unauthorized changes.

Every transaction recorded in the blockchain is time-stamped, meaning the exact time and date of the transaction are recorded. This time-stamping is crucial because it establishes the order of transactions, preventing issues like double spending, where the same digital currency is spent more than once.

For example, if Alice sends digital currency to Bob at 10:00 am, and then tries to send the same currency to Carol at 10:05 am, the blockchain’s time-stamps will show the first transaction occurred earlier, invalidating the second.

• Time-stamps record when each transaction occurs.
• They establish a clear, chronological order of transactions.
• Time-stamping prevents double spending of digital currency.

Blockchain technology allows anyone with access to the ledger to monitor digital currency transactions transparently. Since all transactions are recorded and linked in an unchangeable sequence, users can verify the history of any digital currency unit, tracking its movement from sender to receiver.

For instance, if a user wants to confirm that a payment was made, they can check the blockchain to see the transaction details and verify its authenticity. This transparency builds trust in digital currency systems without relying on a central authority.

• Blockchain provides a transparent record of all digital currency transactions.
• Users can verify transaction history and authenticity.
• It removes the need for a central authority to monitor transactions.

The main benefits of blockchain include enhanced security, transparency, and resistance to fraud. Because the ledger is immutable and decentralized, it is very difficult for malicious actors to alter transaction records or commit fraud.

However, blockchain systems can be slower than traditional databases due to the need for consensus among multiple nodes before adding a new block. Additionally, the technology requires significant computational resources, especially in systems that use proof-of-work consensus mechanisms.

Despite these limitations, blockchain remains a foundational technology for digital currencies, ensuring secure and trustworthy transaction monitoring.

• Benefits: security, transparency, fraud resistance.
• Limitations: slower transaction processing, high computational requirements.
• Essential for trustworthy digital currency transaction tracking.