In order to clear some of the confusion surrounding bitcoin, we need to draw a sharp line to separate it into two components. On the one hand, you have bitcoin-the-token, a piece of code that represents ownership of a digital concept – sort of like a virtual IOU (I Owe You). On the other hand, you have bitcoin-the-protocol, a distributed network that maintains a ledger of balances of bitcoin-the-token. Both are referred to as “bitcoin.”
The system enables payments to be sent between users without passing through a central authority, such as a bank or payment gateway. It is created and held electronically. Bitcoins aren’t printed, like dollars or euros – they’re produced by computers all around the world, using free software.
It was the first example of what we today call cryptocurrencies, a growing asset class that shares some characteristics of traditional currencies, with verification based on cryptography.
Who created it?
A pseudonymous software developer going by the name of Satoshi Nakamoto proposed bitcoin in 2008, as an electronic payment system based on mathematical proof. The idea was to produce a means of exchange, independent of any central authority, that could be transferred electronically in a secure, verifiable and immutable way.
To this day, no-one knows who Satoshi Nakamoto really is.
In what ways is it different from traditional currencies?
Bitcoin can be used to pay for things electronically, if both parties are willing. In that sense, it’s like conventional dollars, euros, or yen, which are also traded digitally.
But it differs from fiat digital currencies in several important ways:
1 – Decentralization
Bitcoin’s most important characteristic is that it is decentralized. No single institution controls the bitcoin network. It is maintained by a group of volunteers coder, and run by an open network of dedicated computers spread around the world. This attracts individuals and groups that are uncomfortable with the control that banks or government institutions have over their money.
Bitcoin solves the “double spending problem” of electronic currencies (in which digital assets can easily be copied and re-used) through an ingenious combination of cryptography and economic incentives. In electronic fiat currencies, this function is fulfilled by banks, which gives them control over the traditional system. With bitcoin, the integrity of the transactions is maintained by a distributed and open network, owned by no-one.
2 – Limited supply
Fiat currencies (dollars, euros, yen, etc.) have an unlimited supply – central banks can issue as many as they want, and can attempt to manipulate a currency’s value relative to others. Holders of the currency (and especially citizens with little alternative) bear the cost.
With bitcoin, on the other hand, the supply is tightly controlled by the underlying algorithm. A small number new bitcoins trickle out every hour, and will continue to do so at a diminishing rate until a maximum of 21 million has been reached. This makes bitcoin more attractive as an asset – in theory, if demand grows and the supply remains the same, the value will increase.
3 – Pseudonymity
While senders of traditional electronic payments are usually identified (for verification purposes, and to comply with anti-money laundering and other legislation), users of bitcoin in theory operate in semi-anonymity. Since there is no central “validator,” users do not need to identify themselves when sending bitcoin to another user. When a transaction request is submitted, the protocol checks all previous transactions to confirm that the sender has the necessary bitcoin as well as the authority to send them. The system does not need to know his or her identity.
In practice, each user is identified by the address of his or her wallet. Transactions can, with some effort, be tracked this way. Also, law enforcement has developed methods to identify users if necessary.
Furthermore, most exchanges are required by law to perform identity checks on their customers before they are allowed to buy or sell bitcoin, facilitating another way that bitcoin usage can be tracked. Since the network is transparent, the progress of a particular transaction is visible to all.
This makes bitcoin not an ideal currency for criminals, terrorists or money-launderers.
4 – Immutability
Bitcoin transactions cannot be reversed, unlike electronic fiat transactions.
This is because there is no central “adjudicator” that can say “ok, return the money.” If a transaction is recorded on the network, and if more than an hour has passed, it is impossible to modify.
While this may disquiet some, it does mean that any transaction on the bitcoin network cannot be tampered with.
5 – Divisibility
The smallest unit of a bitcoin is called a satoshi. It is one hundred millionth of a bitcoin (0.00000001) – at today’s prices, about one hundredth of a cent. This could conceivably enable micro transactions that traditional electronic money cannot.
How do Bitcoin Transactions Work?
If I want to send some of my bitcoin to you, I publish my intention and the nodes scan the entire bitcoin network to validate that I 1) have the bitcoin that I want to send, and 2) haven’t already sent it to someone else. Once that information is confirmed, my transaction gets included in a “block” which gets attached to the previous block – hence the term “blockchain.” Transactions can’t be undone or tampered with, because it would mean re-doing all the blocks that came after.
Getting a bit more complicated:
My bitcoin wallet doesn’t actually hold my bitcoin. What it does is hold my bitcoin address, which keeps a record of all of my transactions, and therefore of my balance. This address – a long string of 34 letters and numbers – is also known as my “public key.” I don’t mind that the whole world can see this sequence. Each address/public key has a corresponding “private key” of 64 letters and numbers. This is private, and it’s crucial that I keep it secret and safe. The two keys are related, but there’s no way that you can figure out my private key from my public key.
That’s important because any transaction I issue from my bitcoin address needs to be “signed” with my private key. To do that, I put both my private key and the transaction details (how many bitcoins I want to send, and to whom) into the bitcoin software on my computer or smartphone.
With this information, the program spits out a digital signature, which gets sent out to the network for validation.
This transaction can be validated – that is, it can be confirmed that I own the bitcoin that I am transferring to you, and that I haven’t already sent it to someone else – by plugging the signature and my public key (which everyone knows) into the bitcoin program. This is one of the genius parts of bitcoin: if the signature was made with the private key that corresponds to that public key, the program will validate the transaction, without knowing what the private key is. Very clever.
The network then confirms that I haven’t previously spent the bitcoin by running through my address history, which it can do because it knows my address (= my public key), and because all transactions are public on the bitcoin ledger.
Even more complicated:
Once my transaction has been validated, it gets included into a “block,” along with a bunch of other transactions.
A brief detour to discuss what a “hash” is, because it’s important for the next paragraph: a hash is produced by a “hash function,” which is a complex math equation that reduces any amount of text or data to 64-character string. It’s not random – every time you put in that particular data set through the hash function, you’ll get the same 64-character string. But if you change so much as a comma, you’ll get a completely different 64-character string. This whole article could be reduced to a hash, and unless I change, remove or add anything to the text, the same hash can be produced again and again. This is a very effective way to tell if something has been changed, and is how the blockchain can confirm that a transaction has not been tampered with.
Back to our blocks: each block includes, as part of its data, a hash of the previous block. That’s what makes it part of a chain, hence the term “blockchain.” So, if one small part of the previous block was tampered with, the current block’s hash would have to change (remember that one tiny change in the input of the hash function changes the output). So if you want to change something in the previous block, you also have to change something (= the hash) in the current block, because the one that is currently included is no longer correct. That’s very hard to do, especially since by the time you’ve reached halfway, there’s probably another block on top of the current one. You’d then also have to change that one. And so on.
This is what makes Bitcoin virtually tamper-proof. I say virtually because it’s not impossible, just very, very, very difficult and therefore unlikely.
Stay expected for the next script on “How to use it”
Source: Ebenezer Nkum / Business.com.gh