Finance and capital markets
- Bitcoin: What is it?
- Bitcoin: Overview
- Bitcoin: Cryptographic hash functions
- Bitcoin: Digital signatures
- Bitcoin: Transaction records
- Bitcoin: Proof of work
- Bitcoin: Transaction block chains
- Bitcoin: The money supply
- Bitcoin: The security of transaction block chains
What is bitcoin? Created by Zulfikar Ramzan.
Want to join the conversation?
- Talking about privacy...could the tax evaders and money launderers use bitcoins transactions and thus we never find them? It seems to me that there is too much privacy already. Billioners hiding taxes in all kinds of secret accounts...is the bitcoin just another tool for them?(80 votes)
- This is very good question and one that definitely comes up in the context of any privacy enhancing technology. When transactions are private, there are both legitimate and illegitimate uses for it. On thing to note is that even though Bitcoin provides some degree of privacy because it employs pseudonyms, a user of bitcoin still has to be very careful to maintain their privacy. For example, it might be possible to associate a bitcoin identity with an IP address of a user. Systems that use pseudonyms aren't completely anonymous since you can correlate transactions that are associated with the same pseudonym and so if any of these transactions inadvertently leaks the identity of the person involved, then the remaining transactions can be tied to this identity as well. It's also worth noting (from a broader historical perspective) that cryptography itself was under scrutiny not that long ago because people felt that it would make it easier for the bad guys to communicate in secret (for these reasons, there was a time when cryptographic algorithms were effectively considered weapons, even from a legal perspective).(118 votes)
- Could a government decide to ban the use of bitcoins in their country. And if so, how would the ban be enforced?(22 votes)
- A case study that would be similar would be the ban of on-line poker in the United States of America. In that case:
Yes, they did ban it.
Enforcement was largely done by:
-Threatening credit card companies and banks with legal action if they were involved in financial transactions that transferred money onto or off of the poker sites involving US citizens. After that the flow of money, from US citizens to poker sites, for the most part, dried up.
-Threatening legal action on the companies themselves. i.e. threaten jail time for executives if they enter US, freeze company assets in the US, etc.
Was it effective ?
Reasonably, but not absolutely.
Now for Bitcoin, they could do the same, i.e. go after bitcoin sellers, threaten credit card companies and banks. They would also be able to threaten vendors who accept bit coins too.
Would it be effective ?
I would speculate that the answer would be: Reasonably, but not absolutely.
Hope this makes sense(47 votes)
- At5:05he mentions supposed "legitimate uses" of the privacy of Bitcoins, but doesn't give any examples. Could anyone list some of those?(8 votes)
- Another example might be making a donation to a political party or to a political cause, but where you don't want your political preferences to be made public. Or along similar lines, maybe you want to make an anonymous donation so that you don't end up on a mailing list or a telemarketer list.(26 votes)
- At about0:04, Mr. Ramzan is talking about differences from other approaches. Are those approaches limited to the more traditional, or are there any other high-tech approaches, possibly rivaling bitcoin?(7 votes)
- In that context, I was thinking primarily of traditional mainstream approaches (e.g., a credit card or Paypal or something of that nature). There are other rival cryptocurrencies that have properties similar to Bitcoin. I didn't address these in the video series. Bitcoin has gotten the most traction and is the most popular. Some of the other cryptocurrency approaches closely resemble bitcoins in many ways and the differences might often be a matter of specific parameters and such (e.g., Litecoin is one such example). If you can understand how bitcoin works, then you will likely be able to understand how these other approaches work. I hope this helps!(20 votes)
- How would I go about buying bitcoins? That would mean the person I buy the bitcoins from I would have to transfer money to them. How can I trust that the person will honour the contact. I guess this goes for every transaction. What happens when there is a dispute?(7 votes)
- To purchase you would go to an exchange like Coinbase, Bitstamp, MTGOX or local bitocins. You would have to put your trust in them.
To generalize quite a bit -- Bitcoin = Cash 2.0. Treat it as such.
Compare cash vs. credit card. With a credit card, you can file a dispute or pay over time etc. If you gave 50 bucks cash to random stranger on the street you cannot dispute it. You could use brute force or try to convince him to give it back to you. For all intents and purposes however, the transaction is final. When you lose your wallet your cash is gone. The same with BTC. There is no overseer.
It is the same with regular transactions. When you hand over cash to the register at your local deli, there is a certain level of faith that you will receive a cup of coffee or whatever you agreed to buy in return.
Bitcoin carries all the same advantages / disadvantages and dangers of cash + many other features outlined elsewhere.Treat it with the same care and caution.
I will say - it is the wild west right now - no regulations, a lot of unknowns. The world and governments are still trying to define what it is. Is it money? A commodity? A protocol? A system? All or none of the above? We live in fascinating times.(17 votes)
- So if I buy a product or something of the like from bob, and I pay 10 bitcoins, wouldn't it be possible (considering what the guy said in the video) that in a day or two it will be only worth say 3-4 bitcoins? In that sense why would someone use this system If there was the prospect of losing wealth (or perceived wealth)?(2 votes)
- Some traditional currencies have had worse problems than Bitcoin. In Post-World War II Hungary, prices doubled every 15 hours. Zimbabwe currently has an annual inflation rate of 5473%. This is caused by over-printing. Bitcoin at least has protection from over-printing because of the predictable generation rate.(12 votes)
- Is the sequence of numbers in binary or any other modes .If it is yes what are those and how was they developed?(2 votes)
- In case it helps, there's more information about the details of the encoding here: https://en.bitcoin.it/wiki/Base58Check_encoding. Underneath, what is being encoded is a cryptographic hash of the public verification key. I left this information out in part since I felt that Bitcoin is already hard enough to understand, and the details of the encoding don't provide any deeper intuition about how and why bitcoin works.(6 votes)
- The price of bitcoins is wildly fluctuating, right?
So this would make a great opportunity for institutions dealing financial derivatives based on bitcoins. A quick search on Wikepedia revealed to me, that there are already hedge funds that have joined in: "Exante Ltd., a Malta-based investment firm, launched a Bitcoin hedge fund"
What implications does that have (1) on the Bitcoin scheme itself , (2) on users of Bitcoins, and (3) on the wider economy?(4 votes)
- You right, prices are unstable, so you shouldn't miss the spot and monitoring market, I get used to such tool http://mining-profit.com/bitcoin(2 votes)
- Does any of the class sessions talk about bit coin mining, that is definitely an interesting topic to cover?(4 votes)
- This whole Bitcoin BS is a Posey scam. Took about two minutes of listening to the "what is bitcoin" to figure that out. The end result will be a vary few success stories and hundreds of thousands of loosers.(1 vote)
But what I wanted to do in this video is talk about what a bitcoin is in more general terms and what differentiating characteristics they have compared to other approaches. So for starters, bitcoin is just an electronic payment system. By electronic payment system, I mean it's just a vehicle, a conduit, by which two parties can transact over the internet. I call these parties Alice and Bob. And let's say Alice for whatever reason wants to give money to Bob over the internet. And this may be because she owes Bob money, or maybe Bob is a merchant and Alice is buying something from Bob. Or maybe Bob is a not-for-profit, and Alice is making a donation to Bob. So there could be many reasons why Alice is trying to pay Bob over the internet in some capacity. Now, if Bob is willing to accept bitcoins, which are a form of electronic payments, then Alice can go ahead and send Bob some value in bitcoins. And really, a bitcoin transaction between Alice and Bob amounts to a specially constructed sequence of numbers that Alice will basically send over to Bob. And this will be done entirely over the internet. These numbers will have certain mathematical properties. They make it hard for someone to really defraud the system or to conduct some type of nefarious action on the system. And the way that Alice is actually going to conduct this transaction in practice is either by installing a special piece of software, which we call a bitcoin client, or she can work with a third-party service that can handle these mechanics for her. But in either case, either the client or the service is going to generate these numbers for Alice. And on the flip side, Bob will also typically either have a piece of software installed or he'll use a third-party service that will take these numbers and allow him to do something else with those numbers. For example, Bob can in turn buy something on his own with those numbers, or he can trade those numbers in for real money and so on and so forth. Now, one of the first questions you might have-- and I kind of alluded to this earlier-- is why would Bob even want to accept bitcoins in the first place? After all, a bitcoin is just a bunch of numbers. What intrinsic value would it conceivably have? And it turns out, quite surprisingly, that bitcoins actually have real-world value. There are more and more merchants popping up each day who accept bitcoins for transactions. There are also bitcoin exchanges, places where you can go and exchange bitcoins for more mainstream currencies. And some of exchanges include-- the major one is one called Mt. Gox. And at Mt. Gox you could exchange a bitcoin for a euro or yen or dollar and so on and so forth. Now the current price of a bitcoin, the current value of a bitcoin in US dollars as of this video, is approximately US$100. per bitcoin. That number is fluctuating. This is a new currency, and there's going to be some fluctuation. But as people understand the currency better, the hope is that that fluctuation will decrease. But I think ultimately, the thing to keep in mind is that the value of a bitcoin is going to be derived from the faith that you have in the value of what you can procure with that bitcoin. It's just like you would for a dollar, a euro or yen. The faith that you have in that currency's value is how you value that currency. Now another question you might have is why do people even bother with bitcoins in the first place. Aren't there other more standard ways? Why couldn't Alice and Bob use Paypal? Why couldn't they use a credit card number to transact? Why couldn't Alice just sent Bob an electronic check? Why not use one of these other approaches that are more well understood, that are more mainstream, that are more established? Why on earth would you possibly want to mess with a good thing? So it turns out that there are a few properties of bitcoins that are worth noting. For starters, there's privacy. It turns out that within the bitcoin ecosystem, within the bitcoin network, people can transact without divulging who they are in the real world. From the perspective of bitcoin, Alice's identity is just going to be a sequence of numbers. And that sequence of numbers is effectively going to function like a pseudonym for Alice. And that sequence of numbers has nothing to do with your real-world identity. Nobody needs to know this is Alice transacting. All they need to worry about is their pseudonym within the system. And this is kind of but not quite like what you would get if you bought something using cash. In that capacity, when you buy something using cash, then you don't have to provide any details or proof regarding who you are in the real world. And that's different from, let's say, using a credit card, where you have to provide your name and your billing address and so on. Or let's say providing an electronic check, where you need to tie that electronic check, typically your bank account details. Now, I do want to also mention here that sometimes when you have a cash list or a transaction that uses cash, there is now the possibility that people might try to use these transactions for malicious purposes to buy illicit goods and services. That definitely is a risk that occurs when you provide anonymity and privacy. But there are certainly legitimate reasons why somebody might want to conduct a transaction privately and not have the whole world know what they're transacting. Another property of bitcoin is that it's open. Literally anyone can get involved. Literally anyone who was an internet connection can make a bitcoin transaction. And all you need to do to get started is, as I alluded to earlier, is download this special bitcoin client. And the bitcoin client, or for that matter you can use a service like Mt. Gox which will effectively do the same work as a client for you. But the short of it is that anyone who has a bitcoin client or who has an account with an exchange like Mt. Gox can engage in bitcoin transactions. That transaction, the details of it, the mechanics of it will be transparent to the user. All the user has to worry about-- all Alice needs to worry about-- is how much money she has and whether she can give that money to Bob. The actual software underneath will take care of all the underlying mechanics of making that transaction work. Now, this is different. When you think about a traditional currency like a dollar, if I want to transact something online, typically I need a bank account, I need a credit card, and so on and so forth. Then we often take it for granted that there are people out there who may not have access to a credit card, who may not have a bank account. For example, in the United States alone it turns out-- and I just looked this up-- the number of households without a bank account, I read it, is somewhere north of about 8%. It's pretty high. There are a lot of people out there who wouldn't be able to conduct a traditional internet transaction, but who can conduct a transaction using bitcoin. And by the way, there are people using bitcoin all over the world. And literally it doesn't matter where you are in the world, as long as you have an internet connection, you can start transacting bitcoins. Now, another property of bitcoin that's worth mentioning is that it's decentralized. There's no bank or centralized entity that can really control what's happening in the bitcoin ecosystem. It's all done in this kind of ad hoc fashion. And what that means is that when you do a transact-- or when Alice transacts with Bob over the internet, that transaction doesn't have to go through a third party. There's no bank that gets in the way of that transaction. And that can have certain benefits as well. For example, that means that no one entity can directly control the money supply of bitcoins. That also means that no one entity can see your assets. Or for that matter, no one entity can reverse a transaction, which is definitely desirable for certain merchants. Some merchants might not be able to conduct business online because of fraud concerns. And if you have a system where the transactions cannot be charged back easily, then from the merchant's perspective, they may be able to inhibit fraud and thereby that might enable their business entirely online. Now I want to point out that this last property of decentralization definitely causes concern among some people or not in bitcoin after all. When you think about it, a central authority like a bank does perform an important function in the context of a traditional currency. For example, banks might validate currencies. They might validate transactions against fraud. Now, in bitcoin, this validation is basically done in a decentralized way by the other parties, the other nodes, in the bitcoin network. Now, the goal of the remaining videos in this series is to walk through the underlying mechanics of bitcoin transactions and really how they're validated, even though the system is decentralized. And there are some pretty amazing techniques that are used to make all this work. So I suspect that at this point, you may have a ton of questions about bitcoin, and that's entirely to be expected. Bitcoin is a very complex protocol. It has many moving parts. And I think it's critical when you're trying to understand something as complex and wrap your head around something as sophisticated as bitcoin, it's important to get exposed to all the parts first so that you can ultimately get a flavor for how they fit together. And hopefully the other videos in this series will help you to understand these different parts and along the way address many of the questions that you might have.