A cryptocurrency public ledger is a record-keeping system. It maintains participants' identities anonymously, their respective cryptocurrency balances, and record all the genuine transactions executed between network participants. Cryptocurrency is an encrypted decentralized digital currency. SQL is not the proper database to store the information of transactions because cryptocurrency is encrypted and decentralized. This project is to make the ledger (Similar to Bank Management System). We can make Transactions of tokens (as a user), create an account, delete it, view the public ledger ( details of sender and receiver (only address of the wallet and tokens transacted)). Scaling and security concerns are one the challenge. Future advancements are shifting to the blockchain database. SQL (Structured Query Language) is a standardized programming language that's used to manage relational databases and perform various operations on the data in them. Python is an interpreted high-level general-purpose programming language. Its design philosophy emphasizes code readability with its use of significant indentation. The transaction's details in the bank's records can be queried and verified by the two parties between whom the transaction took place. Public ledgers work the same way as bank records, although with a few differences. Similar to the bank records, the transaction details on a cryptocurrency public ledger can be verified and queried by the two transacting participants. However, no central authority or network participants can know the identity of the participants. Transactions are allowed and recorded only after suitable verification of the sender’s liquidity; otherwise, they are discarded. The objective of this project is to let the students apply the programming knowledge to a real-world situation/problem and exposed the students to how programming skills help in developing good software. This is also to educate the students on future technologies and make them aware of what's happening in the technological world. Students will demonstrate a breadth of knowledge in computer science, as exemplified in the areas of systems, theory and software development. Students will demonstrate the ability to conduct research or applied Computer Science projects, requiring writing and presentation skills that exemplify scholarly style in computer science. Students will learn about the basic principle, how cryptocurrency works and will develop a curiosity to dive deep into readings blogs (computer science research papers).

My cryptocurrency using a distributed decentralized public ledger in a blockchain (i.e. bitcoin).

What is a hybrid cryptocurrency? A hybrid cryptocurrency is an electronic generated unit that uses advanced encryption techniques for generation, transfer, and validation. What is a bitcoincurrancycash? A bitcoincurrancycash is a hybrid cryptocurrency that was created for people to use as they want. How many bitcoincurrancycash will there be? Only 2100000 will be created. Is this Cryptocurrency anonymous? Yes. No personal info is required, tracked, or collected with any transaction. How do I get bitcoincurrancycash? bitcoincurrancycash are distributed using the drop method. To get the coins all you need is one of our anonymous wallets and wait for the coins to drop on the drop page. What is a wallet? A wallet is an electronic account where you store your coins and where people send you coins. When a wallet is created the first step in the process is creating a Key Pair. The Key Pair is made up of both a Public Key and a Private Key. A hash is created by taking multiple variables and hashing them multiple times to come up with a unique and verifiable address for you to use. Can I have more then one wallet? Yes you can have as many wallets as you like. This is actually encouraged to help maintain anonymity. With each new wallet you will also get a new Key Pair for that wallet. How do I create a wallet? To get your own wallet all you need to do is click the Get A Wallet link in the main nav bar and fill out the simple required info. Do bitcoincurrancycash have any value? The market will decide the coins value. Do I have to store my bitcoincurrancycash at www.bitcoincurrancycash? No. You are free to download your coins and store them locally, offline, or at any other wallet that accepts them. You can even download a copy of your wallet with all your coins in it as a zip file. What is the plain-English Public Ledger? The Public Ledger is an open accounting of all transactions involving bitcoincurrancycash. Each transaction is timestamped and added to the ledger in an ascending order. The transactions are then verified and signed with a private key to ensure their validity. The ledger is a plain English flat file and is available for anyone to download. How does a public ledger decentralize bitcoincurrancycash? In order to provide decentralization the ledgers can also be hosted by third parties. The ledgers are each assigned a UID and their own unique Key Pair. The ledgers are designed to sync with another in an ascending order from the earliest available timestamped ledger to the newest. Since each ledger operates independently and has its own key pair forging a transaction is nearly impossible. Here is an example of how it works: wallet c9ca29fab55d732ba68cbf7346252fcf creates a coin. This transaction is first recorded on the local ledger. Once it has been recorded it is then broadcast to all other ledgers on the network starting with the oldest first. As it records the transaction it is also checking the coins validity and history. The Ledger API first checks to see if a transaction has been recorded on each ledger it discovers in the network. If the transaction is already recorded it then moves to the next available ledger. If it hasn't been recorded it then records the transaction and keeps repeating this process.

My visual representation of a blockchain - in the rails format. If you're not sure what a blockchain is, it is way to decentralize transactions. Blockchains are a digital ledger in which transactions made in bitcoin or another cryptocurrency are recorded chronologically and publicly. Quite simply, each transaction holds the details of the previous transaction, creating a chain of data(or 'Blocks') - hence the name blockchain. Here is a quick preview of what I have running, but if you want to mess around a little more, you can check out the project live on Heroku.

Bitcoin, the most famous decentralised digital currency, is the largest cryptocurrency globally in market capitalisation. It was introduced to the world for the first time in January 2009 and has had a volatile trading history ever since. The transactions occur via a Peer-to-Peer (P2P) network and are recorded in the blockchain, a public ledger. Here, an attempt has been made to predict, using regression (particularly LSTM), the closing price of Bitcoin at the end of each hour from 1st March 2016 to 24th November 2018 based on the available hourly data. It is multivariate because the closing price depends on the different prices, the volume traded, as well as trend, i.e. the popularity of the terms associated and time series as the values vary across time.

At the peak of the financial crisis of 2008, murmur began in tiny online communities of cryptography enthusiasts, computer scientists and hackers. A white paper styled research paper titled “Bitcoin Peer-to-Peer Electronic Cash System” was broadcasted on a cryptography mailing list of the community. The author? Satoshi Nakamoto. Satoshi wasn’t an unheard name within the communities. Years before the world heard of him, someone using the Satoshi pseudonym had been posting to forums and emailing fellow developers, never confirming a location, gender, nationality or even a real name. The first mention The real identity of the creator of Bitcoin is one of the most gripping modern-day mysteries. Especially since the April of 2011, when Satoshi left a final message with a fellow developer “I’ve moved onto other things.” And just like that, he disappeared. Satoshi was the pioneer of an entirely new kind of money that has taken the world by storm and has gone on to achieve a market cap of more than $1Trillion. Yet, the creator remains anonymous. In 2007, Satoshi began coding the first version of Bitcoin in the C++ programming language. Before sharing it widely on the cryptography mailing list, Satoshi shared his ideas with the founders of proto-cryptocurrencies Hashcash and b-money. The idea was met with scepticism by the community that was used going through revolutionary ideas that did not see the light of the day. Satoshi’s legacy The appeal in his paper however, was the idea of building a cash system completely independent from the existing financial system. Satoshi’s answer to the issue of digital currency duplication, which he referred to as “the double-spending problem”, was to use a peer-to-peer network. This system would eliminate the need for any central authority to validate transactions. To his admission, prior attempts to digital currencies failed because of their centrally controlled nature. Traditional transactions are made based on trust. Intermediaries such as banks or internet commerce platforms are trusted to complete transactions as they fall under a centralised authority. Satoshi’s proposed decentralised system did not work based on trust. Instead, this trust-less system was the basis of Blockchain. A Blockchain is a publicly shared ledger that can document all transactions. Who is Satoshi Nakamoto? Satoshi left the text “The Times 03/Jan/2009 Chancellor on brink of second bailout for banks” of the Genesis block, the first block to be mined on the Bitcoins blockchain. It was considered a potential easter egg. The text was from a headline on that day’s Times of London. Additionally, his liberal use of British phrases has led people to believe that Satoshi must hail from the United Kingdom. However, Satoshi once described himself as a 37-year-old man living in Japan. Theories have also been devised that Satoshi Nakamoto is a cohort and not an individual. If not, he is a highly intelligent developer with a multifaceted understanding of Economics, Cryptography and Peer-to-peer networking and amongst other things. Another favourite suspect for theorists to zero down on as Satoshi has been Hal Finney. Finney was the first cryptographer to receive Bitcoin when Nakamoto finished the first-ever transaction on Bitcoins blockchain. Even on his deathbed, Finney denied these claims. Len Sassaman is considered another possible suspect. Sassaman killed himself after battling depression in 2011. Coincidentally, in Satoshi’s last few communications, he sent a cryptic email to a fellow developer that he “probably won’t be around in the future.” Questions around Satoshi’s identity remain unanswered and may remain so. Satoshi might want to stay anonymous for legal reasons. It is widely believed that Satoshi holds more than a million bitcoin, which would amount to tens of billions of US dollars. Whether he lives to witness this growth is unknown. This mystery might forever remain unsolved.

The ABC of Cryptocurrency actually begins at D which stands for digitalization. In an era of technological advances, going from analog to digital was arguably the largest leap of faith. Music was not on a cassette, photographs were not on paper, a collection of data-keeping was on cloud and money was a matter of minutes away. This digitalization of money was at the epicenter of the concept of cryptocurrency. Cryptocurrencies refer to digital money that does not exist in physical form such as coins or notes. These are virtual assets with a sum of value attached to them. These can be stored on a digital wallet which may be accessed from a computer or a smartphone device. These devices are also used for transferring this currency in exchange for goods and services. A technology called Blockchain is what enables the functioning of these transactions. Blockchain is a decentralized system that organizes and records transactions across multiple computers, making it a secure network. Cryptocurrency is maintained using a distributed ledger, which unlike regular money makes it decentralized in nature. This ensures a great degree of transparency, along with anonymity through the use of encryption. Cryptocurrency exists beyond the control of a central authority and any government. When an exchange is made using cryptocurrency, there isn’t involvement of a third party, making it a peer-to-peer transaction. These transactions are recorded on a massive database known as Blockchain. Single transactions are represented by a block that is added to a chain of transactions, where it is logged forever. The prime benefit of this is that blockchain is not stored in a central location but scattered on a large network of computers, thus making it impossible to be tampered with. Blockchain transactions are kept protected by a complex system. Transactions are protected by the use of public and private keys. A user’s wallet or account address in a Cryptocurrency system has a public key, meanwhile the owner of the wallet can authorize transactions with the use of a private key. The lack of an involvement of a third party ensures minimum processing expenses. The process of holding cryptocurrencies is also termed mining, much like how traditional currency is mined. Cryptocurrency such as Bitcoin can be mined through high power computer machines that can work on incredibly tough equations. These machines can also add transactions to the blockchain to check its validity and ensure authenticity. Mining is an incredibly complex procedure as it controls the number of coins up for grabs. The other way to hold a stake in cryptocurrency is by buying some. Much like traditional shares, cryptocurrency can also be bought and sold. To purchase cryptocurrency, one needs a wallet on an internet software program that stores your funds. Traditional money can be used to purchase cryptocurrency. The value of these currencies is determined by its supply and demand, hence making it an instrument for investments. Cryptocurrency and the wide possibilities it presents with itself is surely one of the most exciting stages of the evolution of the concept of money. From coins to bitcoins to beyond, the road is endless.

Bitcoin is a worldwide cryptocurrency and digital payment system[13]:3 invented by an unknown programmer, or a group of programmers, under the name Satoshi Nakamoto.[14] It was released as open-source software in 2009.[15] The system is peer-to-peer, and transactions take place between users directly, without an intermediary.[13]:4 These transactions are verified by network nodes and recorded in a public distributed ledger called a blockchain. Since the system works without a central repository or single administrator, bitcoin is called the first decentralized digital currency.[13]:1[16] Besides being created as a reward for mining, bitcoin can be exchanged for other currencies,[17] products, and services in legal or black markets.[18][19]

With over $385 billion in market capitalization (as of 31st August, 2021), Ethereum is the largest public blockchain that supports smart contracts. It is also the second most valuable cryptocurrency, just after Bitcoin. In this work, we have done exploratory data analysis of the Ethereum blockchain. We started by giving an overview of the Digital Ledger Technology and then explained several consensus mechanisms. Further, we described blockchain technology and gave an explanation of how it works. Then we stated the different types of blockchains being used in the industry today. A detailed description of the Ethereum blockchain is then given by deeply talking about the Ethereum model and the Ethereum Roadmap. After that, the data analysis setup is reported and the dataset schema is presented along with a dataset relational diagram. Further, we move on to the analytics and provide a generic analytics of the Ethereum blockchain related to transactions, gas, addresses, smart contracts and ETH price. Finally, we present a focused analytics of transactions, volume, accounts and smart contracts.

Eleven thousand years ago with the emergence of the system of bartering the first men and women started exchanging goods.Back then people would only trade with other people within their tribe that they knew and trusted ,but as years went by and the population started growing exponentially it became harder and harder to personally know and trust everyone moreover people went from exchanging simple objects to trading different kind of assets and, therefore individuals started calling on middleman like banks or governments to protect their interests but what happens when the trust replace in such third parties is shattered. A anonymous person or a group of people or maybe a woman created a white paper on which it was writen that About a peer to peer electronic cash system using the new cryptocurrency bitcoin although. you may be familiar with bitcoin but you may not be familiar with the technology required for it to work block chain. So what is block chain? Block chain is a system that stores information in a network of personal computers called nodes there is no central entity like a bank or a government controlling it the system is what do we called distribute it that means that all the computers in the network have the same information. Imagine the block chain like a big public ledger that lists all the transactions that have been executed betweeen two parties each transaction is time stamped and immutable that means that once you add a transaction or an information to the block chain you cannot go back and change it or delete it the people in the network that add and verify the transaction are called miners to do so they take the transaction information run it through a secure hash algorithm that provides them with unique output called a hash. The hash his stored on the block and not the transaction information that it means that if you see or have the hash you cannot go back and retrieved the transaction information this ensures privacy each hash is added to a ledger and the ledger is stored in the block each block is linked to the previous one creating a chain the block chain. Of course the block chain doesn't store just a list of transactions it can provide proof of existence for any document like audio files images or even complete medical records there are lot of use cases with block chain for one main reason the power block chain lights in the fact that it can prove that are unique event occurred at the certain time that event can be either financial transaction older creation of a new document now this charecterstic is very powerful as you can imagine and many sectors are very interested in like health care in health care as well there are many use caeses for block chain for one main reason ensuring trust in the medical community ,in scientist or in pharmaceuticial industry is essential to leverage scientific progress and improve the quality of care. For example a problem that I believe you have all faced when you go to the doctors even if it's in a very critical state your doctor often has to run a series of tests to know what's going on with you even if the colleague from another hospital have already done so previously. As there is no way for a hospital to retrieve the information from another hospital of course that results in a massive loss of time money and eventually life. This brings us to a big problem in the healthcare sector that is the lack of interoperability.The medical and scientific communities don't have access to data and when they finally find the information it becomes hard to find the patient and ask for consent but now imagine we have a system like a ledger. let's say that lists all the information about the patient or his medical history and now imagine that the ledger is public and accessible for doctors nurses pharmacists scientists imagine that we have a system that allows us to access the data only upon consent given by the patient now stop imagining it because it's happening and it's called the blockchain. It can be done in four really easy steps 1.Health care providers collect information from the patient. 2.The data is stored in existing databases in hospitals 3.then this is where it gets tricky a hash is creating from each source of the data and is redirected to the blockchain for the patient decides who has access to his own medical records 4.Healthcare stakeholders (validator) can create the blockchain and access the information. Now here comes a problem, how we can manage and create access to the information. The answer is smart contracts . Smart contracts are contracts that are written as code into the blockchain when a triggering event is hit the contract automatically executes itself for instance Here in this case when a doctor asks for permission to access the information if the patient gives consent the contract automatically allows the doctors to see the results blockchain. Smart contracts provide two big advantages first the system is finally patient-centered because the patient now owns his medical records of course the patient cannot just go and modify everything or deleted but he can decide who has access to the information we are solving the trust issue in the healthcare system secondly the blockchain can act like a catalog that lists all the medical records of the patient and all his medical history (maybe genetic) that way the next time you go to the doctors instead of having him doing all the tests again he will just have to contact his colleague and ask for the information of course with patient consent.

Transactions in cryptocurrencies are recorded on a public ledger called a blockchain.

The blockchain is the technology that underpins cryptocurrencies, and it is essentially a public ledger that records all transactions.

Cryptocurrency is a digital or virtual form of money secured by cryptography, designed to enable fast, borderless, and decentralized transactions. Unlike traditional currencies issued by governments, cryptocurrencies run on blockchain technology—public, distributed ledgers that ensure transparency and security. Since the launch of Bitcoin in 2009.

What is Martin Luther King? MLK is the native cryptocurrency of Martin Luther King, a crypto payment system created by Martin Luther King Labs Inc. MLK is its “digital asset designed for global payments”. Martin Luther King intends to compete with the money transfers usually carried out by traditional banking systems. The MLK would allow users to send money at reduced fees, attracting potential interest from the general public and banks. Two of Martin Luther King's key value propositions are tiny transaction costs and less than five-second transaction finality. The company was founded in 2022 by several people associated around a round table and is based on the work of these people indicated in the list of administrative members, at the origin of the MLK Ledger in 2022. It is headed by Tom A. Kemp as general manager. The MLK Ledger is an open-source crypto ledger powered by a network of peer-to-peer nodes. She has targeted high level partnerships with webnode of America and proton.

RVCI is an open source platform cryptocurrency which will be used by millions of users around the world. Through which you can make instant payments online or in a store. RVCI is an evolutionary stage in crypto currency controlled by a decentralized public ledger which is the stepping stone for the future of banking and in a whole the complete financial system.

Blockchain technology enables distributed public ledgers that hold immutable data in a secure and encrypted way and ensure that transactions can never be altered. While Bitcoin and other cryptocurrencies are the most popular examples of blockchain usage, this “distributed ledger technology” (DLT) is finding a broad range of uses. Data storage, financial transactions, real estate, asset management and many more uses are being explored

Bitcoin is a decentralized blockchain based cryptocurrency that has taken the world by storm. Since its introduction in 2009, it has grown tremendously in terms of popularity and market cap. The idea of having a decentralized public ledger while maintaining anonymity and security attracted the attention of developers and customers alike. Special nodes in the bitcoin network, called Miners are responsible for making the network secure by using a concept called Proof-of-Work. A certain degree of anonymity is also maintained as no personally identifiable information of a person like a name, address, aadhaar number etc is linked to the bitcoin wallet. In terms of bitcoin, a user is anonymous if different interactions of the user cannot be linked to each other or the user. Recent research shows that bitcoin is not that anonymous as it appears to be. The inherently public nature of blockchain technology makes it difficult to achieve privacy. The purpose of this paper is to review how varying degrees of user privacy is maintained in bitcoin cryptocurrency. This paper is divided into two main segments. The first segment explores privacy enhancing techniques adopted in bitcoin. The second segment critically analyzes these techniques.

Dystater is a decentralized digital currency, without a central bank or single administrator, that can be sent from user to user on the peer-to-peer dystater network without the need for intermediaries. Transactions are verified by network nodes through cryptography and recorded in a public distributed ledger called a blockchain. Dystaters are created as a reward for a process known as mining. They can be exchanged for other currencies, products, and services. Research produced by the University of Cambridge estimated that in 2017, there were 2.9 to 5.8 million unique users using a cryptocurrency wallet, most of them using Bitcoin. Dystater was launched on the 31st of January 2021.

Mining Your Bitcoin A look at what it means to mine your bitcoins! Bitcoins! The cryptocurrency everyone knows about, talks about, owns or wants to own. A recent surge in the interest towards traditional money alternatives and cryptocurrency has led everyone to be aware of the premier cryptocurrency - Bitcoin. There are two ways to obtain Bitcoin. The simpler method is to invest in cryptocurrency exchanges. One can open a wallet based account with these exchanges and buy the cryptocurrency of their choice. An investor may then decide to hold, sell or buy in order to trade cryptocurrency. The second and more complex method is mining. Understanding mining Mining is the process of creating new cryptocurrency coins by solving extremely complicated mathematical problems. Mining is also an integral component of maintaining a blockchain ledger that legitimises new transactions. This is important in the absence of a central authority in play that could verify and act upon invalid transactions or stop the counterfeiting. The mining process thus achieves a decentralised consensus through proof of work. When a miner obtains Bitcoins by mining, there is no conversion of fiat currency to cryptocurrency. Miners, however, incur operating costs. The process of mining When someone invests or trades in cryptocurrency, the details of these transactions are lodged on a public ledger, called the blockchain. The transaction however is only complete after a miner verifies it as legitimate and makes an entry on the blockchain. Miners are in a race against each other to solve a problem. Rewards are paid to miners who discover a solution to a complex hashing puzzle. The first to do so gets to add a block to the blockchain. The miner gets 6.25 bitcoins as a reward for their efforts. With each successful transaction, new coins enter into circulation, thus completing the mining process. The verification of these newly minted coins as legitimate is achieved by repeating the entire process again. The mining maths Miners try to come up with a 64-digit hexadecimal number otherwise known as a hash that is less than or equal to the target hash. While the mathematical efficiency required to achieve the same is subjective, coming up with a hash involves a lot of guesswork. Mining difficulty is raised as the number of miners trying to guess this hash increases. The Bitcoin network aims to have one block added to its blockchain around every 10 minutes, to ensure a smooth operation. The more miners that join in to solve the problem the sooner a solution is found. This is why to stabilize the block production rate Bitcoin evaluates the difficulty of mining after every 2016 block, which is roughly two weeks. Making money from mining To earn Bitcoins a miner needs to be the first to offer the solution. To add to their efficiency miners require specialised computer hardware that offers a high hash rate. This hardware, also known as application-specific integrated circuits (ASIC) or a graphics processing unit (GPU) , became a part of a mining rig. With increasing competition, it has become almost impossible to engage in mining using a home-based computer setup. The hardware essential for mining rigs is highly specialised and expensive. It consumes high amounts of electricity, in a way limiting the profitability of miners. The reward amount is revised and cut in half every 210,000 blocks or around 4 years. Due to the volatility of Bitcoin’s market price, it is impossible for a miner to estimate his profits. Mining is an extremely time and energy-consuming task. Sure, the rewards are worth the efforts but the probability to win these makes mining a difficult choice for investors. Regardless of the way one decides to obtain Bitcoins, owning a stake in the first cryptocurrency is definitely exhilarating.

The development of blockchain can be roughly divided into three stages, marked off by important developments and inventions. Even though the technology has only recently debuted in the grand scheme of the Internet, it’s easy to mark its early milestones. Blockchain for Bitcoin The pseudonym developer of Bitcoin, Satoshi Nakamoto is widely credited for outlining blockchain in its current form. Though ideas were floating in the Computer Science communities, the technology was initially conceptualized to support the Bitcoin network. The technology found varied applications over the course of its development. However, it was designed specifically to advance the horizons for digital currency. At its inception, blockchain was to be set up as a shared public ledger that could support a cryptocurrency network. Blockchain technology in its present forms relies heavily on the features it was established with and Bitcoin’s blockchain largely remains unchanged. Satoshi’s idea for blockchain was to make use of 1MB worth of information on transactions, per block. These blocks were placed on a chain through a complex cryptographic verification process, making the placement immutable. Hence, creating a highly secure permanent record. Contracts – The next development Blockchain was believed to be a revolutionary technology that had the potential to do more than documenting digital transactions. Innovation was at its prime. The founders of Ethereum, for instance, introduced the idea of smart contracts, which became another milestone for blockchain development. Contracts in the traditional sense are managed between two entities, sometimes under the oversight of a third mediating entity. Smart contracts, on the other hand, are self-managed on a blockchain. These contracts are actually computer programs that can oversee all aspects of an agreement, from creation to execution. Changes and adjustments within such contracts are updated when conditions are met, such as expiration dates. This holds the potential to manage documentation with no involvement of an outside entity and can be applied to almost all fields of business. Footsteps towards the future Blockchains’ biggest challenge remains scaling. Cryptocurrencies have time and again tried to revise their blockchain in order to ensure scalability, improve transaction processing times, and avoid bottlenecking. The next big milestone for blockchain technology will target an easier scalability. New applications beyond the cryptocurrency industry are also being constantly developed. Blockchain technology has already seeped into the world of supply-chain management effectively. The technology also offers a tremendous level of security given its decentralized verification process, which makes it great for identity management. This mechanism could ideally be used for identity verification. The culmination of blockchain with other adjacent technologies will also give rise to exciting technological developments. Given the endless possibilities that yet remain to be discovered, blockchain technology could emerge as the biggest boon from the cryptocurrency boom. The era of innovation has only just begun in the world of blockchain technology.

When Satoshi Nakamoto dropped his whitepaper conceptualising Bitcoin, he addressed the problem of double-spending that his predecessors in digital cash could not solve. Satoshi offered a solution for the same. This solution became the base technology that the entire cryptocurrency industry today stands on. What is Double-spending? Double spending is a potential flaw that arises with digital currency where the same tender is being spent multiple times. This happens as digital information is easy to reproduce and manipulate. Simply put, double spending is spending the same money twice. Physical currency cannot be replicated easily. Offline transactions are made using physical currency, the parties involved can verify its authenticity and transfer ownership. Physical currency can only be spent once. One coin or note cannot be used to make multiple purchases. Digital assets on the other hand are a set of codes that can be copied and sent to several recipients. This duplication eventually leads to a loss in the value of the asset. Double-spending of digital assets is highly probable as it is impossible for a recipient to tell whether funds being spent have been spent already, without a mediating verification service. Digital assets can solve the problem of double-spending by either opting for a centralised clearing counterparty, such as a financial institution or by a decentralised approach. What is the Decentralised approach? Double spending in decentralized systems is challenging, as it equips an immutable public transaction ledger that is maintained by servers on computer systems scattered around the world. These servers receive the information of a transaction as a broadcast. The broadcast may be received by various servers at varying times. Hence there is a possibility for a transaction to be duplicated or the same currency to be used twice. The servers render the second transaction invalid. To ensure that the servers do not go out of tally, a consensus mechanism is adopted. Bitcoin, for example, uses a consensus mechanism known as proof-to-work. A necessary agreement is reached on various transactions by synchronising the majority of the nodes in a network. Bitcoin uses a historical public ledger facilitated through its blockchain network that legitimises ownership and transfer of assets. Bitcoin transactions take time to verify as the process involved is an intricately complicated one, requiring immense computing power. Are double-spending attacks common? Hackers have tried to break into the bitcoin verification system by sending fraudulent transaction logs to one server and broadcasting another to the rest of the network. However, more Bitcoin thefts happen due to a lack of a secure storage system. Another risk for double-spending can occur if a user controls more than 50% of the computing power involved in maintaining the blockchain. In such a case a user will be able to manipulate the consensus mechanism and repeat transactions by clearing out the ledger. Double-spending attacks are minimalized by the security a blockchain offers.