Internship

I did my internship from BuyUcoin. I worked as marketing and recerch analyst. During the internship I learnt about bitcoin and blockchain concept thoughly. Below I had very briefly described all the main concepts I came across during my internship

  • BuyUcoin

  • Bitcoin

  • Working of Bitcoin

  • Money through Bitcoin

  • Blockchain

  • Segwit

  • Security in bitcoin
BuyUcoin is the India's first multi cryptocurrency wallet and exchange. It is easiest and most secure way to sell, store, use digital currency and altcoin like Bitcoin, Ethereum, Litecoin, Ripple, Bitcoin Cash, etc with INR in india.
It simplifies buying and selling cryptocurrency.

Lets see how BuyUcoin works

-> We need to create our free digital currency wallet.
-> Then verify KYC(know your customer/identity) and connect our Bank Account.
-> Then add INR in our BuyUcoin wallet.
Now we can easily buy and sell through bitcoins.

Visit BuyUcoin

https://www.buyucoin.com/

Bitcoin


Bitcoin is a digital currency created in 2009. It follows the ideas set out in a white paper by the mysterious Satoshi Nakamoto, whose true identity has yet to be verified. Bitcoin offers the promise of lower transaction fees than traditional online payment mechanisms and is operated by a decentralized authority, unlike government-issued currencies. Today's market cap for all bitcoin (abbreviated BTC or, less frequently, XBT) in circulation exceeds $7 billion.

There are no physical bitcoins, only balances kept on a public ledger in the cloud, that – along with all Bitcoin transactions – is verified by a massive amount of computing power. Bitcoins are not issued or backed by any banks or governments, nor are individual bitcoins valuable as a commodity. Despite its not being legal tender, Bitcoin charts high on popularity, and has triggered the launch of other virtual currencies collectively referred to as Altcoins.

Working of Bitcoin


Bitcoin is one of the first digital currencies to use peer-to-peer technology to facilitate instant payments. The independent individuals and companies who own the governing computing power and participate in the Bitcoin network, also known as "miners," are motivated by rewards (the release of new bitcoin) and transaction fees paid in bitcoin. These miners can be thought of as the decentralized authority enforcing the credibility of the Bitcoin network. New bitcoin is being released to the miners at a fixed, but periodically declining rate, such that the total supply of bitcoins approaches 21 million . One bitcoin is divisible to eight decimal places (100 millionth of one bitcoin), and this smallest unit is referred to as a Satoshi. If necessary, and if the participating miners accept the change, Bitcoin could eventually be made divisible to even more decimal places.

Bitcoin mining is the process through which bitcoins are released to come into circulation. Basically, it involves solving a computationally difficult puzzle to discover a new block, which is added to the blockchain, and receiving a reward in the form of few bitcoins. The block reward was 50 new bitcoins in 2009; it decreases every four years. As more and more bitcoins are created, the difficulty of the mining process – that is, the amount of computing power involved – increases. The mining difficulty began at 1.0 with Bitcoin's debut back in 2009; at the end of the year, it was only 1.18. As of April 2017, the mining difficulty is over 4.24 billion. Once, an ordinary desktop computer sufficed for the mining process; now, to combat the difficulty level, miners must use faster hardware like Application-Specific Integrated Circuits (ASIC), more advanced processing units like Graphic Processing Units (GPUs), etc.

How to Make Money with Bitcoin: 10 Ways to Earn Cryptocurrency


There are a number of ways that individuals can earn Bitcoin online. Unfortunately, just as in real life, there is no such thing as a free lunch. Any way of earning Bitcoin online will require something in exchange, whether it’s your time or your knowledge or your computer’s processing power.
Some of the methods outlined below will involve minimal effort but will also result in minimal returns. Other means of earning Bitcoin online may be more lucrative but they will require you to have a certain level of knowledge and expertise about the industry and the market. Therefore, although it may appear to some that Bitcoin, and cryptocurrency in general, is an easy way to make money, it is not as easy as some might expect without the requisite knowledge (a principle that can unsurprisingly be applied to any industry).
However, should you be interested in earning Bitcoin online it may be worth considering some of the below options, ranging from the least difficult (and least paid!) to the more substantial roles available in the Bitcoin ecosystem.
  • Micro Earnings


    Although micro-earnings is the easiest method in which to earn Bitcoin, it is also probably the most time consuming of all the methods discussed, especially when taking into consideration the amount of money to be made. Micro earning websites pay you in Bitcoin for completing small tasks. In return you can get a (very) small amount of Bitcoin. The most popular forms of micro earnings are as follows:
  • Paid-to-Click Websites


    As suggested by the name, these websites pay users in Bitcoin for visiting certain websites or viewing certain advertisements. There are many PTC websites that will pay negligible amounts in Bitcoin for clicks and views, with Ads4BTC probably being the most famous and the most popular. This website allows users to choose between viewing ads that are 5 seconds, 10 seconds or 20 seconds, with different fees being awarded for each. Based on the prices offered by Ads4BTC, if you had 20 second ads running for an entire day, you would make less than $10 per day, so this may not be a viable option for most.
  • Bitcoin Faucets


    A Bitcoin faucet is a type of website that gives away small amounts of Bitcoin to its users, with owners making money by placing ads on their website and pay individuals who visit the ads or complete surveys. This industry amounts of over 50% of the traffic on leading Bitcoin websites today. Faucets let visitors earn a percentage of the Bitcoin that they give away to any visitors that you brought in. This has resulted in users using a Bitcoin faucet rotator that allows users to quickly surf different faucets and earn a commission through rotation links for each faucet visited by you. However, similar to PTC websites, Bitcoin faucets are not a realistic way to earn good money, with even the best faucet rotators being applied still only enabling users to make no more than $1-2 per day.
  • Micro Jobs


    Micro jobs are small tasks that can be completed for small amounts of Bitcoin. Websites such as Coinworker offer such tasks, which may involve simply testing a plugin to see if it is successfully compatible with a browser, or just retweeting a post. Again, the money is small but there is potential to earn a little bit more than the faucets of PTC websites.
  • Writing about Bitcoin


    If you’re knowledgeable about Bitcoin, enthusiastic about the cryptocurrency industry in general and willing and able to share your knowledge, then you can also earn Bitcoin by doing so. The amount that can be earned by writing about Bitcoin varies, but can be quite lucrative depending on the level of expertise that you have on the subject.
  • BitcoinTalk Signature Campaigns


    The BitcoinTalk Forum Signature campaign pays for users to write posts on the BitcoinTalk forum which includes a product campaign in the signature. Payment levels depend on your membership level on the BitcoinTalk forum, with very little Bitcoin being available for users that aren’t a full member of the forum (to obtain full membership, you need at least 120 posts). Most campaigns also have certain requirements for posters, such as a minimum word limit or a requirement that no advertisements are directly included in posts. In addition, some campaigns may include a minimum and/or a maximum weekly post count.
    The amount of money that can be made from these campaigns varies depending on the number of quality posts that you could make as a user that achieve the word count minimums. Depending on the campaign you may be able to make $50-100 for 24 hours of work, exclusive of the posts needed to obtain full membership to the forum. In addition, due to some campaigns operating only allowing for a maximum number of posts per week, there may not be sufficient income within a campaign to earn substantial amounts.
  • Bitcointalk Bounties


    Lots of new Cryptocurrency companies also offer “Bounties” for performing other tasks, such as creating YouTube videos, blogging and posting on social media. You will earn differing amounts depending on how many followers you have so it can be useful to build your Facebook or Twitter accounts and participate in different campaigns. You will typically be paid after the ICO has taken place and receive some of the coin or token from the company you helped promote.
  • Writing for blog and news sites


    It is at this point that the potential for making good money begins to rise, although the corresponding requirements for knowledge about Bitcoin also increase at the same time. There are an ever-increasing number of blogs and news sites that require dedicated writers to discuss Bitcoin and other cryptocurrencies and, depending on your level of understanding about your subject, there are a virtual limitless number of options available to writers, with good quality writers being paid between $30-100 per 1,000 words. At this level writers can also choose their payment methods, whether it be in Bitcoin or in fiat currency. Websites such as Coinality is a good place to start if you are looking to find jobs writing about Bitcoin online.
  • Affiliate Marketing


    If you take the writing route for Bitcoin and your blog or website is a success, there is potential to make money through Bitcoin affiliate marketing. This is a form of marketing where you can get paid a certain percentage of commission for every referral that you bring to an existing Bitcoin business. If the business operates an affiliate programme, and your blog is read by enough people who link to the business and purchase the product offered, then the commissions can potentially be unlimited, for minimal outlay other than the drafting of the original blog post.

  • Provide Bitcoin-related services


    When it comes to cryptocurrency, if your level of expertise is more on the technical side rather than the writing side, there are plenty of opportunities to get involved in cryptocurrency development projects. Most of the companies currently operating in the cryptocurrency industry are start-ups with limited infrastructure in place. Therefore, they often need everything from software developers to web developers to mining experts to online marketers. Depending on the size of the startup a role such as this can vary from being a contracting job that can be completed remotely, or alternatively could be a full-time job. The amount that can be earned from a role such as this is obviously dependent on the type of role, the level of expertise that you bring to the role and the number of hours that you will be dedicating to the role.

  • Bitcoin Lending


    There are potentially significant earnings to be made in Bitcoin lending, but there is also significant risk. Bitcoin lending tends to operate through intermediary websites such as Bitbond and the concept is as simple as it sounds. You act as a bank, lending your Bitcoin to another person at a certain level of interest. Because the market is unregulated the levels of interest are generally much higher than the standard bank rate meaning that there is a potential for high returns. However, on the flip-side, the unregulated nature of the transaction means that in the event that the borrower does not pay back the Bitcoin to you, there is little recourse available for you to enforce the loan.
    The volatility and the risk associated with the Bitcoin lending market means that it is probably a market only accessible to very large holders of Bitcoin, due to the level of risk and the potential expense in enforcing a loan if something goes wrong. However, if handled correctly, there is huge potential market in this sector.
  • Bitcoin Mining


    Early adherents to the Bitcoin industry have made significant fees through mining Bitcoin. Mining Bitcoin is the process by which new coins are created. Mining is carried out using certain computer programmes and utilises the processing power of the miner’s computer. At its inception, Bitcoin mining was relatively simple and the earliest miners were able to mine thousands and thousands of Bitcoin with limited expenditure.
    However, at the same time, the value of Bitcoin was nowhere near where it was today and therefore any large profits being made from mining didn’t really begin to happen until a number of years after when the value of Bitcoin began to rise. Nowadays, Bitcoin mining is much harder. Each Bitcoin that is mined requires more processing power and therefore mining Bitcoin now involves significant processing power and can no longer be done without specialized equipment.
    In addition, the costs of the electricity used to power this equipment is phenomenal, with Bitcoin mining currently estimating to be using the same power per day as a country the size of Morocco. Because of this, most Bitcoin mining has been taken over by companies who can make profit by scale based on buying large amounts of processing hardware at a discount as well as locating themselves in an area with extremely cheap electricity. For this reason, China is by far the largest Bitcoin mining country (mining over 60% of Bitcoin), followed by Georgia, Sweden and the US.
    If you have a decent graphics card on your computer, there are many other currencies or “alt-coins” you could mine though, take a look at some of our guides:
    • ZCash Mining
    • Monero Mining
    • Ethereum Mining
    • DigiByte Mining
    • Musicoin Mining

  • Bitcoin Trading


    There is huge potential to make money on trading in Bitcoin, but it takes a level of expertise and knowledge about the market in the same way that trading on any other financial market does. In addition, the cryptocurrency market is extremely volatile and therefore may not suit everybody’s tastes and risk appetite. The first issue with trading is that almost all of the trading exchanges operate through Bitcoin or Ethereum, meaning that if you wish to trade in cryptocurrency and don’t own any, you will probably need to own some (with some exceptions).
    Websites such as Coinbase or CEX both allow users to purchase cryptocurrency by credit or debit card, or alternatively to purchase via a bank transfer. Once purchased, you can then transfer your Bitcoin to whichever exchange you wish to operate on. If you wish to consider trading, here are some of the options:
  • Day Trading


    Day trading is buying and selling Bitcoins on the same day on the basis of small, short-term price fluctuations in the market. Such fluctuations may be based on market trends or simply rumours. Traders can trade Bitcoin against other cryptocurrencies or against fiat currencies such as the US Dollar.

  • Contracts for Difference


    Although similar to day trading, CfD does not involve actually buying or selling any Bitcoin. Instead, you buy a contract for Bitcoin, meaning that you don’t actually have to hold or store any Bitcoin. One of the advantages of this is that you can short Bitcoin, meaning that if the price goes down, your profit goes up, allowing you to hedge your trades. One of the disadvantages is that you have no control over the Bitcoin you trade with, as you are not the owner of any Bitcoin or the controller of the private key. It can therefore only be used for trading purposes.
  • Binary Options


    Binary options (so-called because the only option is to win or to lose) is a trade strategy that allows you to predict if the price of Bitcoin will rise or fall in a certain period of time. If the rise or fall occurs within the set period, you will receive the payout agreed upon when entering into the option. If it does not occur, then you lose your investment.
    We recently reviewed IQ Option which is the largest site for trading Binary options.

Conclusion


Although not exhaustive, these are some of the most popular ways in which you can earn income online. As noted at the outset, there is no such thing as free Bitcoin and something will have to be given in return, whether it’s time or expertise or both. However, with an ever-expanding market the demand for Bitcoin expertise and Bitcoin related products means that there has never been a better time to get involved in Bitcoin.

Blockchain


What is a 'Blockchain'


A blockchain is a digitized, decentralized, public ledger of all cryptocurrency transactions. Constantly growing as ‘completed’ blocks (the most recent transactions) are recorded and added to it in chronological order, it allows market participants to keep track of digital currency transactions without central recordkeeping. Each node (a computer connected to the network) gets a copy of the blockchain, which is downloaded automatically.
Originally developed as the accounting method for the virtual currency Bitcoin, blockchains – which use what's known as distributed ledger technology (DLT) – are appearing in a variety of commercial applications today. Currently, the technology is primarily used to verify transactions, within digital currencies though it is possible to digitize, code and insert practically any document into the blockchain. Doing so creates an indelible record that cannot be changed; furthermore, the record’s authenticity can be verified by the entire community using the blockchain instead of a single centralized authority.

BREAKING DOWN 'Blockchain'


A block is the ‘current’ part of a blockchain, which records some or all of the recent transactions. Once completed, a block goes into the blockchain as a permanent database. Each time a block gets completed, a new one is generated. There is a countless number of such blocks in the blockchain, connected to each other (like links in a chain) in proper linear, chronological order. Every block contains a hash of the previous block. The blockchain has complete information about different user addresses and their balances right from the genesis block to the most recently completed block.
The blockchain was designed so these transactions are immutable, meaning they cannot be deleted. The blocks are added through cryptography, ensuring that they remain meddle-proof: The data can be distributed, but not copied. However, the ever-growing size of the blockchain is considered by some to be a problem, creating issues of storage and synchronization.

Blockchains and Bitcoin


The blockchain is perhaps the main technological innovation of Bitcoin. Bitcoin isn’t regulated by a central authority. Instead, its users dictate and validate transactions when one person pays another for goods or services, eliminating the need for a third party to process or store payments. The completed transaction is publicly recorded into blocks and eventually into the blockchain, where it’s verified and relayed by other Bitcoin users. On average, a new block is appended to the blockchain every 10 minutes, through mining.
Based on the Bitcoin protocol, the blockchain database is shared by all nodes participating in a system. Upon joining the network, each connected computer receives a copy of the blockchain, which has records, and stands as proof of, every transaction ever executed. It can thus provide insight about facts like how much value belonged a particular address at any point in the past. Blockchain.info provides access to the entire Bitcoin blockchain.

Extensions of Blockchains


To use conventional banking as an analogy, the blockchain is like a full history of a financial institution's transactions, and each block is like an individual bank statement. But because it's a distributed database system, serving as an open electronic ledger, a blockchain can simplify business operations for all parties. For these reasons, the technology is attracting not only financial institutions and stock exchanges, but many others in the fields of music, diamonds, insurance, and Internet of Things (IOT) devices. Advocates have also suggested that this kind of electronic ledger system could be usefully applied to voting systems, weapon or vehicle registrations by state governments, medical records, or even to confirm ownership of antiquities or artwork.
Given the potential of this distributed ledger technology (DLT) to simplify current business operations, new models based on blockchain have already begun to replace the expensive and inefficient accounting and payment networks of the financial industry. Blockchain technology could free up billions of dollars: A recent Goldman Sachs report suggested that it could save stock market operators up to $6 billion a year.
While banks were initially hesitant to explore these technologies because of their concerns about potential fraud, they have started looking into how the blockchain might provide generous cost savings by allowing back-office settlement systems to process trades, transfers and other transactions much faster.
In fact, the first international blockchain transaction was completed on October 24, 2016. Brokered by the Commonwealth Bank of Australia and Wells Fargo & Co (WFC), the $35,000 deal involved Australian cotton trader Brighann Cotton Marketing, which purchased 88 bales cotton from its U.S. division in Texas and sent it to Qingdao, China.

Blockchains and Tech Companies


Attracted by the idea of removing the middleman and moving towards democratization and decentralization, tech startups are adopting blockchain technology with the goal of disrupting a variety of industries.
Among the startups leveraging blockchain technology for IOT devices is 21 Inc. The Silicon Valley-based startup received a total of $116 million in funding in 2015. According to the firm, the funding will be used to embed Bitcoin mining chips into connected IOT devices and cell phones.
BTCJam, a P2P lending platform headquartered in San Francisco, specializes in providing Bitcoin-based loans. Over the last year, the company has lent more than $15 million.
Storj is just one company that is currently beta-testing the concept of developing cloud storage based on a blockchain-powered network, with the goal of improving security while decreasing users' dependency on a single storage provider's centralized system. The company even offers users the opportunity to rent out storage capacity they do not need, similar to the way that property owners rent out extra rooms on Airbnb.
ProofofExistence one of the first non-financial companies to utilize blockchains, is a platform for executing contracts. It uses DLT to store encrypted information, thus enabling a transaction that cannot be replicated to be linked to a unique document.
Even established firms are interested. Microsoft Corporation (MSFT) has also expressed interest in blockchain technology, having recently formed a partnership with blockchain firm ConsenSys. In December 2015, Microsoft and ConsenSys announced Ethereum Blockchain as a Service (EBaaS) on Azure — Microsoft’s cloud computing platform — to provide a single-click, cloud-based environment to clients and developers. In June 2016, the two companies started developing an open source, blockchain-based identity system for people, products, apps and services.

Advantages of Blockchains


Efficiencies resulting from DLT can add up to some serious cost savings. DLT systems make it possible for businesses and banks to streamline internal operations, dramatically reducing the expense, mistakes, and delays caused by traditional methods for reconciliation of records.
The widespread adoption of DLT will bring enormous cost savings in three areas, advocates say:
Electronic ledgers are much cheaper to maintain than traditional accounting systems; the employee headcount in back offices can be greatly reduced. Nearly fully automated DLT systems result in far fewer errors and the elimination of repetitive confirmation steps. Minimizing the processing delay also means less capital being held against the risks of pending transactions. In addition, some smaller number of millions will be saved by shrinking the amount of capital that broker/dealers are required to put up to back unsettled, outstanding trades. Greater transparency and ease of auditing should lead to savings in anti-money laundering regulatory compliance costs, too.
Blockchain's removal of almost all human involvement in processing is particularly beneficial in cross-border trades, which usually take much longer because of time-zone issues and the fact that all parties must confirm payment processing. Blockchain systems can set up smart contracts or payments triggered when certain conditions are met. The blockchain cotton transaction mentioned above, for example, used a smart contract that automatically made partial payments when the cotton shipment reached specific geographic milestones.

Financial Industry Blockchain Initiatives

R3 CEV,a fintech innovation company, and a consortium of more than 80 of the world’s biggest financial institutions is bankrolling research into methods to harness the speed, accuracy, and efficiency of the blockchain. In 2016, it successfully trialed five distinct blockchain technologies in parallel, using multiple cloud technology providers in a first-of-its-kind test, and is currently marketing its Corda, a "financial-grade" distributed ledger platform for commercial use.
In 2017, after three years of work, Goldman Sachs Group Inc. (NYSE: GS) received a patent for the SETLcoin, which would create near instantaneous trade settlement times (see Here's How the SETLcoin Trade System Will Work).
In 2016, four major banks came together to develop the utility settlement coin (USC), a new digital currency whose use (mainly to buy securities) would be recorded via blockchain. Led by UBS Group AG (NYSE: UBS), they include Bank of New York Mellon Corporation (NYSE: BK), Deutsche Bank AG (NYSE: DB) and Banco Santander S.A. (NYSE: SAN), along with broker ICAP PLC (LON: IAP). In 2017, six more banks joined them: Barclays Bank, Credit Suisse Group AG (CS), Canadian Imperial Bank of Commerce, HSBC Holdings PLC (HSBC), MUFG and State Street Corp (NYSE: STT). The consortium is aiming for a 2018 commercial release.
However, for that to happen, a USC-based system or its competitor would need to obtain the approval of commercial institutions, central banks and regulators. And, although it is clearly almost there, blockchain technology is not quite ready for prime time.

Hurdles in Adopting Blockchain Technology


The roadblocks to DLT today are not just technical. The real challenge is politics, regulatory approval, and the many thousands of hours of custom software design and front and back-end programming still required to link up the new blockchain ledgers to current business networks.
Problems that still need to be addressed include:
  • DLT must interface with other parts of the operational processes seamlessly. Blockchain should enable more rapid setup, training, and reduce problem resolution time. Achieving the efficiency gains must be easy enough/cheap enough for all parties involved to grasp and leverage.
  • Security also remains a concern. Several central banks, including the Federal Reserve, the Bank of Canada and the Bank of England, have launched investigations into digital currencies. According to a February 2015 Bank of England research report: “Further research would also be required to devise a system which could utilize distributed ledger technology without compromising a central bank’s ability to control its currency and secure the system against systemic attack.”
  • Banks are not interested in an open-source model for identity. Both banks and regulators want to maintain close control. The development of a single digital identity passport authorizer is a critical next step.
  • Regulation is also critical in creating an open digital environment for commerce and financial transactions. Current physical certificates must be digitized to gain the full benefits of a fully electronic system. Other questions to be answered include: Who is responsible for maintaining and managing the blockchain? Who admits new participants to the blockchain? Who validates transactions? and who determines who sees which transactions?

  • Investing in Blockchains


    Investors interested in getting on the blockchain technology bandwagon will find it is now easier than ever to do so. In 2015, the venture capital concern Digital Currency Group launched, intending to build what it refers to as "the largest early-stage investment portfolio in the digital currency and blockchain ecosystem." Additionally, according to a report published by the American Software-as-a-Service (SaaS) company NASDAQ Private Market, the amount of venture capital being funneled into cryptocurrency-using firms was anticipated to exceed $1 billion. Companies have even become so interested in the technology that many have begun to play around with the idea of creating their own private blockchains.
    Nevertheless, blockchain startups are not without challenges. Among the most significant is the fact that most consumers simply do not understand the extremely complicated concept of blockchain technology. In order to overcome this challenge, companies will need to find ways to precisely explain what they do in easily understandable language – and how they intend to deal with issues like secure online transactions and consumer privacy.

    The Bottom Line


    Given the incredible opportunity for decentralization, blockchain technology offers the ability to create businesses and operations that are both flexible and secure. Whether companies will succeed in deploying blockchain technology to create products and services consumers will trust and adopt remains to be seen. Nevertheless, this is definitely a space investors should watch. The demand for blockchain-based services is on the rise, and the technology is maturing and advancing at a rapid pace.
    The potential applications for blockchain technology are almost without limit. At the moment, several of these applications are still either in the development stage or in beta testing. With more money being poured into blockchain-based startups, consumers should not be surprised to see DLT services and products becoming more mainstream in the near future.

Segwit


DEFINITION of 'SegWit (Segregated Witness)'


SegWit is the process by which the block size limit on a blockchain is increased by removing signature data from Bitcoin transactions. When certain parts of a transaction are removed, this frees up space or capacity to add more transactions to the chain.
Segregate means to separate, and Witnesses are the transaction signatures. Hence, Segregated Witness in short, means to separate transaction signatures. The concept of SegWit was formulated by Dr. Pieter Wuille.

BREAKING DOWN 'SegWit (Segregated Witness)'


The bitcoin blockchain consists of multiple systems distributed across a peer-to-peer network. These systems are called nodes and serve as the administrators of Bitcoin transactions. All transactions made in Bitcoin are duplicated across these nodes, making it virtually impossible to hack into and corrupt a transaction.
The transaction data that is shared across the multiple nodes consists of two components – inputs and outputs. There could be one or multiple inputs and outputs involved in a transaction. The output is the public address of the recipient. The input is the public address of the sender. The sender needs the recipient’s public address in order to send funds to him or her. The majority of space in a transaction consists of a signature, a part of the input, which verifies that the sender has the required funds to make a payment. So in effect, a Bitcoin moves from inputs to outputs for each transaction transmitted. Once each of the nodes have verified the transaction as valid, the transaction is included in a block which is added to the chain or the general ledger for public access.
The problem that the Bitcoin platform is facing is that as more and more transactions are being conducted, more blocks have to be added to the chain. Blocks are generated every 10 minutes and are constrained to a maximum size of 1 megabyte (MB). Due to this constraint, only a certain number of transactions can be added to a block. The weight of the transactions, represented by the blocks, is weighing down the network and causing delays in processing and verifying transactions, in some cases, taking hours to confirm a transaction as valid. Imagine all Bitcoin transactions that have been carried out since the inception of Bitcoin in 2009 sitting on the blockchain and still piling up. Long term, the system would not be sustainable if a radical change is not made.
Dr. Pieter Wuille suggests that to solve this problem, the digital signature needs to be segregated from the transactions data. This process is known as Segregated Witness or SegWit. Digital signature accounts for 65% of the space in a given transaction. SegWit attempts to ignore the data attached to a signature by stripping off the signature from within the input and moving it to a structure towards the end of a transaction. This would increase the 1 MB limit for block sizes to a little under 4 MB. In addition to slightly increasing the capacity size of blocks, SegWit also solves the problem where a receiver could intercept and modify the sender’s transaction ID in a bid to get more coins from the sender. Since the digital signature would be detached from the input, the unscrupulous party would have no way of changing the transaction ID without also nullifying the digital signature.
As of May 2017, SegWit is yet to be put in effect. 95% of the Bitcoin community have to agree to this new process and switch to the new Bitcore Core client for at least two weeks, before SegWit can be successfully activated. So far, only an estimated 30% have signed up for it.

What makes the Bitcoin network secure?


What does a secure network mean?


When you're talking about security in respect to Bitcoin (and its surrounding network), you need to accomplish the following goals:
  • Coins cannot be double spent
  • Balances of who owns which coins must be accurate
  • It is very difficult to "steal" someone's coins using a network attack

Preventing Double Spends


The network's main innovation in preventing a double spend is the distributed ledger (the blockchain.) By broadcasting all transactions to all nodes and waiting for those nodes to confirm a certain number of times, you're allowing the network to self-police. It might be easy to compromise a single node, but it'd be difficult to compromise enough nodes and have them all allow a double spend. This is where you hear fears of a "51% attack" - in theory, if you had 51% of the computing power that verifies transactions, you could allow double spends.

Maintaining Balances


A key part of Bitcoin's security relies on the concept of hash functions. A hash function will take a unique input, and from that input produce a unique output. If I ran the number 1 through a fictional hash function, it would always produce something like FFTA9. The Blockchain uses this to secure transactions. A group of these transactions are wrapped into a block, and the hash of those transactions is broadcast. If someone wanted to remove a transaction or insert a fake one, they'd somehow have to find a way to do that while outputting the same hash. While in theory this could be possible, it is extremely unlikely and would require more computing power than exists today.

Stealing Coins


The network broadcasts public addresses, which are derived from hashing a public key (that pairs with a single private key.) Only people with the private key can "sign" for coins to be spent, so if you wanted to get someone's coins, you'd need to get the private key from the public data. In most cases, this is impossible: each transaction uses random values to hide this. However, you might've heard of some attacks where it WAS possible to decode the private key. If you use a weak random number source, with enough data, you could get the private key for a given public key. That's why a major initiate in the Bitcoin community is to use standards-backed, open source and audited libraries for your cryptography and randomness. With the proper libraries, it becomes mathematically infeasible to steal someone's private key.

Contact Me!