2346 days ago • cryptodaily
Developers Discuss the State of Bitcoin Privacy at Baltic Honeybadger Conference
A major highlight of the recent Baltic Honeybadger 2017 conference in Riga, Latvia was the final panel at the end of the second day of events, which consisted of a number of well-known developers in the Bitcoin ecosystem. During the panel discussion, the developers shared their thoughts on the current state of privacy in Bitcoin. Various participants on the panel pointed out the close relationship between privacy and scalability, the privacy issues with light wallets, and how the ecosystem is now on the cusp of a number of different privacy enhancements.
Bitcoin Privacy Improves as the Technology Scales by Default
The first panelist to comment on the topic of privacy in Bitcoin was applied cryptography consultant and sometimes Bitcoin Core contributor Peter Todd. For Todd, the main point he wanted to get across was that improved privacy is something that is inherently associated with better scalability of the system.
“The whole reason why Bitcoin has such terrible privacy is everyone has everyone else’s transactions, and any scalability measure that makes Bitcoin scale better inevitably is going to make fewer people have fewer people’s data,” said Todd. Todd noted that people who use centralized off-chain services like Coinbase may have better privacy than those who are transacting on the public blockchain, depending on their threat model.
For example, Coinbase knows everything that Coinbase users are doing, but North Korea knows nothing about these transactions because they’re processed on Coinbase’s internal servers. “As we go scale this tech up, if we do so successfully, we will get improved privacy no matter what we do,” added Todd, who pointed to the Lightning Network as a perfect example of this concept in practice.
In terms of privacy-focused altcoins, such as Monero and Zcash, Todd claimed the scalability situation is actually worse. “Zcash and Monero both essentially have accumulators that mean that nodes need more data to go and process transactions,” explained Todd. “There are tradeoffs around this . . . but a lot of this tech isn’t there yet and it just makes things more complex.”
Better Privacy Needs to Be Balanced with Usability
When SatoshiLabs CTO Pavol Rusnak commented on Bitcoin privacy, he brought up the issue of usability in terms of future privacy improvements. In his view, there is a triangle of tradeoffs between privacy, security, and usability that must be understood. As a specific example, Rusnak pointed to MimbleWimble, which is a proposal for a much more private and scalable blockchain. Rusnak noted that while the proposal may improve the privacy situation, it also degrades usability by removing the ability to view one’s transaction history on the blockchain.
“The question is: If there is a coin that has security and privacy but it loses usability because of its transaction history, will people be interested in using it?” asked Rusnak. “I think yes. But it’s still — we have a lot of people who are Trezor users and they really tend to look into their transaction history. They put labels everywhere.” Rusnak went on to add that there is no “silver bullet” that can be applied to every use case out there.
The Privacy Problem for SPV Wallets
As the microphone was handed over to Libbitcoin lead maintainer Eric Voskuil, he brought up the issue of wallets based on simplified payment verification (SPV). “I’d like to get client-server scenarios out of the P2P protocol,” said Voskuil. “I think it’s creeping in a bad direction.” In Voskuil’s view, shortcuts have been taken in order to implement more user-friendly bitcoin wallets. Some of these shortcuts have created new problems, and Voskuil specifically pointed to the issue of bloom filters, which are used in SPV wallets.
“You can think of it as a DoS attack against nodes, it gives up privacy, there’s just nothing good about it,” said Voskuil. As Voskuil explained, those who use these bloom filters are giving some anonymous node on the network — which may actually be a node operated by a blockchain analytics company — an IP address to attach to a transaction. In Voskuil’s view, it would be better to simply connect to a server via the Tor network and publish a transaction there. That way, no one would know where it came from.
Ciphrex CEO and Bitcoin Core contributor Eric Lombrozo agreed with Voskuil’s comments on bloom filters, and he indicated that the sync time associated with operating a full node is what pushes users to these less-secure, less-private wallets in the first place. “Right now, verification is not that cheap, and that’s a problem because then you basically end up outsourcing this to third parties, and that changes the entire security model of Bitcoin,” said Lombrozo. Lombrozo went on to refer to bloom filters as “a hack” that was never really fleshed out or well designed at all. “You don’t have to download entire blocks, but you do give up tremendous amounts of privacy,” Lombrozo added.
In the past, Chaincode Labs’s Matt Corallo, who was a co-author of the Bitcoin Improvement Proposal (BIP) related to bloom filters, has said he regrets ever writing up the idea. Lombrozo also pointed to Lightning Network developers Olaoluwa Osuntokun and Alex Akselrod’s proposal for client-side filtering in light clients, which would improve the privacy issues related to the use of SPV. “It gives you better privacy,” explained Lombrozo. “You can actually download a filter associated with a block and on your node you can actually check whether that block might contain transactions you’re interested in before you download the entire block.”
Lombrozo also brought up BIP 151, which was authored by Bitcoin Core contributor Jonas Schnelli. The point of this proposal is to encrypt the data being sent over the P2P protocol, which could offer an obvious privacy improvement for light clients in terms of making their network communications less public. Blockstream CEO Adam Back also agreed with the idea that bloom filters are not very good for user privacy. However, Back also clarified that most of the light wallets available today, even the ones on smartphones, are not pure SPV wallets.
Instead, the user usually connects to a server provided by the wallet developer or points the wallet at the user’s own full node running at home (or some combination of the two). For this reason, Back wondered whether there is much of a need for SPV wallets in Bitcoin. “If you already have two crosschecks — a semi-trusted node and an option of your own node — then do we really need the SPV protocol?” asked Back. “Because you’re allowing yourself to be surrounded by people who are trying to spy on your privacy — the people doing the kind of Chainanalysis kinds of things are running lots of crawlers on the network and being SPV providers to many wallets.”
On the Cusp of Improvements in Bitcoin Privacy
The most privacy-focused individual on the panel may have been JoinMarket developer Adam Gibson. JoinMarket is the most widely-used implementation of CoinJoin, which is a way for users to mix their bitcoins with each other and obscure their transaction history. Gibson continued Todd’s point on the relationship between privacy and scalability by specifically talking about Blockstream Mathematician Andrew Poelstra’s concept of scriptless scripts. “The way I’d put it is it’s like taking the semantics of the transaction off chain, so you may still have a transaction but the meaning of it is obscured [and] it becomes a lot more private,” explained Gibson. “For example, you might do a coin swap where you and I swap the history of our coins, but we do it in such a way that it just looks like a totally ordinary transaction.
In fact, it’s impossible to distinguish from an ordinary transaction.” According to Gibson, there are many other examples of ways in which data can be taken off of the base Bitcoin blockchain layer to improve privacy. Like Todd, Gibson pointed to the Lightning Network as another obvious example. Gibson also pointed out that he’s now more excited by the concept of Confidential Transactions due to a recent paper that describes a way to massively improve the efficiency of these types of transactions, which are meant to mask the amounts associated with transactions.
The JoinMarket developer went on to describe a world where Confidential Transactions are combined with CoinJoin to mask the most important attributes of Bitcoin transactions. In fact, Gibson indicated that this sort of combination can be done in a manner that makes privacy-conscious transactions cheaper than traditional Bitcoin transactions. Gibson also pointed to Schnorr signatures and MAST as two other upcoming improvements that could have implications for user privacy, but he also indicated that there is not much users can do to improve their own privacy today — outside of using JoinMarket or practicing good Bitcoin privacy hygiene such as avoiding address reuse.
This is all in addition to the previous privacy improvements for light clients described by Lombrozo. “There’s a lot of very close things at this point, which makes me a bit more positive than I might have been before,” concluded Gibson.
2360 days ago • cryptodaily
How can I buy a Bitcoin?
Now that you understand the basics of Bitcoin, the next logical step is to actually get some. But how? This brief guide will teach you all you need to know. At present, Bitcoins are either bought directly from other people through marketplaces, or purchased at a Bitcoin exchange. They can be paid for in a number of ways, from cold, hard cash, to debit and credit cards, to a wire money transfer, and even using other cryptocurrencies. It largely depends on where you live and from whom you’re buying your Bitcoins.
How can I buy Bitcoins?
Despite the popularity of Bitcoin as the world’s leading cryptocurrency, and the serious discussion of it at many financial centres around the globe, it remains surprisingly difficult to use PayPal or your credit card to purchase Bitcoins, depending on the jurisdiction in which you live. Of course, the reason has less to do with Bitcoin, and more to do with the transaction methods themselves. These sorts of purchases can be easily reversed with nothing more than a telephone call to the card company, or by raising a report with PayPal. When you’re talking about the transfer of Bitcoins, it is difficult to prove that any goods have actually changed hands. This is the reason most private sellers, and almost all Bitcoin exchanges, do not accept credit cards or PayPal for such transfers. That said, the options have recently grown for consumers in certain countries.
Where do I keep my Bitcoins?
Before you think about buying Bitcoins, you’re going to need to get a Bitcoin wallet. Though ‘wallet’ is the accepted terminology, you’re better off thinking of it as a sort of bank account, specifically for your Bitcoins. As with any such set-up, there are different wallets you can choose from depending on the level of security you require for your funds, with some of the higher-specification wallets attracting a higher fee to initialise and run. Some wallets act like a regular spending or current account, and can be reasonably compared to a regular leather wallet. Other accounts include the sort of encryption and security that would not seem out of place in a major financial centre, or even in the military. There are four main types of Bitcoin wallet: • A software wallet, which remains stored on your computer’s hard drive
• A web-based, online wallet
• A vault wallet, which protects your Bitcoins by keeping the wallet offline
• A multisig (that is, a multiple-signature) wallet, which requires the use of a number of keys in order to protect the account.
It is important to note that none of these options is entirely invulnerable to hacking or other forms of online theft, and each has its own downsides as far as security is concerned.
How can I buy Bitcoins with a credit or debit card?
If you’re based in the United Kingdom, there are three main providers who offer the opportunity to make a Bitcoin purchase with your credit or debit card – Coinbase, CoinCorner and Bittylicious. All three accept 3D secure-enabled debit and credit cards, so long as they are on the MasterCard or Visa networks.
How can I buy Bitcoins with cash?
This is where face-to-face (FTF) or over-the-counter (OTC) transactions come into play. The easiest way to acquire Bitcoins, provided you live somewhere that allows you do so, is to make a FTF trade with a local Bitcoin seller. It allows you to avoid any potential hassle with the banks and offers a certain amount of anonymity to you as a buyer. It should be stated up-front that you will still need a Bitcoin wallet, and that you should be very wary of a local seller who advises otherwise, or who says that they will set one up for you.
Just as you would not trust another person with your bank account details, nor trust them to set one up in your name, you should make sure that the only person with the details of your Bitcoin wallet is you. There are online services, such as LocalBitcoins, where you can arrange your transaction and agree a price before meeting up with the seller. The purpose of this is to ensure that a cost of the trade can be set prior to making the payment. LocalBitcoins also operates an escrow facility (in which the funds are deposited with them to be paid out to the seller, and vice versa – the site essentially acting as a middleman for the trade). This adds a further layer of protection to the trade. Face-to-face is a slight misnomer. It is entirely possible never to meet the seller. If an amount is agreed, you can make a cash transfer from your account into theirs, or you can go to their local bank and make a cash deposit into theirs, and then provide them with a receipt.
Once they have this, the seller should deposit the Bitcoins with you, for storage in your Bitcoin wallet. However, genuine face-to-face trades, where you meet the individual concerned, can and do take place, every day. As with any cash transaction involving a person you don’t know, you should have consideration of your own personal security, particularly if you are looking to trade a sizeable amount. First of all, you should always arrange to meet in a busy public place. The flip-side of this, but worth repeating, is that you should never arrange to meet in a private home, no matter how good a deal you’re getting. If the seller tries to give you some reason as to why this has to happen (that his Bitcoin wallet security is set-up in a way that it has to be operated from his home machine, for instance), then politely walk away and find another seller. The potential gains for your Bitcoin portfolio are not worth the attendant risks. In short, you should take all the precautions you would normally expect to take when walking around with a large amount of cash. Now, it’s possible that the seller will not need an actual cash transaction.
An online bank transfer might be entirely acceptable to them, but they want you do do it there and then, so they can see the money going over, before they reciprocate with sending you the Bitcoins. Some sellers might even allow you to make a payment via your PayPal account, though most would be understandably reluctant to do so, preferring a non-reversible method of payment, for all the reasons mentioned earlier in this piece.
If you hope to pay by PayPal, ensure that you confirm that this is OK with the seller before meeting up, to avoid embarrassment and wasting one another’s time. Depending on the person you are trading with, they might impose a premium of between 5% and 10% on top of the current Bitcoin exchange price, to allow for the convenience and privacy of a face-to-face trade (and to compensate for their time in meeting you to conduct the transfer).
Any reputable trader should be willing to set the price before you meet, but many will institute a window of opportunity for whatever deal you strike, not wanting to wait for too long, just in case the value of Bitcoin takes a sudden and dramatic shift. It should go without saying that, if you're meeting someone for a face-to-face Bitcoin sale, you will need some way of accessing your Bitcoin wallet. If this involves bringing along your tablet, smartphone, or laptop, then so be it, but don’t forget the other essential component: a live and active internet connection to be able to confirm the transfer.
A word of caution
When considering a face-to-face purchase of Bitcoins, you would be well-advised to check that such a trade is legal in your area, before agreeing to meet. There is little reason why it shouldn’t be but, since the laws for such transactions differ from one jurisdiction to the next, it is best to be sure ahead of time. Also, there is a risk you might excite the interest of local law enforcement if you’re exchanging large sums of cash with another person in a public place. While unlikely, and easily explained, there is always the chance that a passing police officer might suspect you of trading in something a bit more illicit that cryptocurrency.
Bitcoin Meet-ups
Of course, one-to-one trades might not be your cup of tea, and that’s understandable. A popular form of direct trading in Bitcoins is the meet-up group. You can use a website like meetup.com and see if there is such a thing in your local area. The principle is the same as a face-to-face exchange, but in a group setting that allows for a greater feeling of safety among the individual attendees, and also allows you to learn more about the Bitcoin market from other members of the group.
Bitcoin ATMs
This is a relatively new concept, but Bitcoin ATMs are increasing in both number and availability across the UK. Several vendors have either released, or are experimenting with these machines: BitAccess, Genesis Coin, CoinOutlet, Robocoin and Lamassu to name but a few. The principle is simple – a Bitcoin ATM serves the same function as a face-to-face transaction, only with a machine instead of another human being. You insert your cash into the ATM and then (depending on the vendor) you either receive a paper receipt containing the relevant codes you’ll need to load your new Bitcoins into your wallet, or you receive a QR code that you will be able to scan with your mobile phone. The rate of exchange has been seen to vary wildly with these machines, and many of them add a fee for the convenience of the service, which can be as high as 8% of the transaction cost.
Other ways to purchase Bitcoins
Consumers in the States who are classed as underbanked (that is, they don’t have sufficient access to the sorts of mainstream products and financial services usually offered by retail banks), can use expresscoin, who have recently emerged to cater to this very market, accepting wire transfers, personal cheques, and money orders to pay for Bitcoins. No such service exists in the UK at this moment in time.
What countries can I buy Bitcoins from?
Bitcoin is expanding rapidly into many different markets, and it is not only possible, but expected, that a Bitcoin trader will want to buy in one market and sell in another, as the different exchanges offer different rates. With third-party organisations like CoinBase available to assist the transactions, buying Bitcoins from a different country is now easier than ever. While the spread of Bitcoin is hardly universal at this stage, every major financial centre currently operates at least one Bitcoin exchange, and analysts predict that this growth will continue into developing markets.
At present, the following countries all have a trade in Bitcoins:
Asia: Singapore
Australasia: Australia
Europe: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Finland, Greece, Hungary, Ireland, Italy, Jersey, Latvia, Liechtenstein, Malta, Monaco, Netherlands, Norway, Poland, Portugal, Republic of Ireland, San Marino, Slovakia, Slovenia, Spain, Sweden, Switzerland, United Kingdom
North America:
Canada, United States of America As with any international financial transaction, it is important to make yourself aware of the various laws and conditions that might impact on your transfer, be it your payment to the seller, or your receipt of Bitcoins from them. If in doubt, it may be worth your time speaking to, or hiring, a dedicated Bitcoin broker to make the exchange on your behalf, for a fee.
In conclusion
Buying Bitcoins is certainly not as easy as many newcomers suspect, although the ways and means by which to do so are increasing and developing all the time. As Bitcoin continues to make its presence felt in the global marketplace, the process of making Bitcoin transactions will become ever more simple, as a way of enticing developing markets, new investors, and new consumers to the currency.
2360 days ago • cryptodaily
How can I buy a Bitcoin?
Now that you understand the basics of Bitcoin, the next logical step is to actually get some. But how? This brief guide will teach you all you need to know. At present, Bitcoins are either bought directly from other people through marketplaces, or purchased at a Bitcoin exchange. They can be paid for in a number of ways, from cold, hard cash, to debit and credit cards, to a wire money transfer, and even using other cryptocurrencies. It largely depends on where you live and from whom you’re buying your Bitcoins.
How can I buy Bitcoins?
Despite the popularity of Bitcoin as the world’s leading cryptocurrency, and the serious discussion of it at many financial centres around the globe, it remains surprisingly difficult to use PayPal or your credit card to purchase Bitcoins, depending on the jurisdiction in which you live. Of course, the reason has less to do with Bitcoin, and more to do with the transaction methods themselves. These sorts of purchases can be easily reversed with nothing more than a telephone call to the card company, or by raising a report with PayPal. When you’re talking about the transfer of Bitcoins, it is difficult to prove that any goods have actually changed hands. This is the reason most private sellers, and almost all Bitcoin exchanges, do not accept credit cards or PayPal for such transfers. That said, the options have recently grown for consumers in certain countries.
Where do I keep my Bitcoins?
Before you think about buying Bitcoins, you’re going to need to get a Bitcoin wallet. Though ‘wallet’ is the accepted terminology, you’re better off thinking of it as a sort of bank account, specifically for your Bitcoins. As with any such set-up, there are different wallets you can choose from depending on the level of security you require for your funds, with some of the higher-specification wallets attracting a higher fee to initialise and run. Some wallets act like a regular spending or current account, and can be reasonably compared to a regular leather wallet. Other accounts include the sort of encryption and security that would not seem out of place in a major financial centre, or even in the military. There are four main types of Bitcoin wallet: • A software wallet, which remains stored on your computer’s hard drive
• A web-based, online wallet
• A vault wallet, which protects your Bitcoins by keeping the wallet offline
• A multisig (that is, a multiple-signature) wallet, which requires the use of a number of keys in order to protect the account.
It is important to note that none of these options is entirely invulnerable to hacking or other forms of online theft, and each has its own downsides as far as security is concerned.
How can I buy Bitcoins with a credit or debit card?
If you’re based in the United Kingdom, there are three main providers who offer the opportunity to make a Bitcoin purchase with your credit or debit card – Coinbase, CoinCorner and Bittylicious. All three accept 3D secure-enabled debit and credit cards, so long as they are on the MasterCard or Visa networks.
How can I buy Bitcoins with cash?
This is where face-to-face (FTF) or over-the-counter (OTC) transactions come into play. The easiest way to acquire Bitcoins, provided you live somewhere that allows you do so, is to make a FTF trade with a local Bitcoin seller. It allows you to avoid any potential hassle with the banks and offers a certain amount of anonymity to you as a buyer. It should be stated up-front that you will still need a Bitcoin wallet, and that you should be very wary of a local seller who advises otherwise, or who says that they will set one up for you.
Just as you would not trust another person with your bank account details, nor trust them to set one up in your name, you should make sure that the only person with the details of your Bitcoin wallet is you. There are online services, such as LocalBitcoins, where you can arrange your transaction and agree a price before meeting up with the seller. The purpose of this is to ensure that a cost of the trade can be set prior to making the payment. LocalBitcoins also operates an escrow facility (in which the funds are deposited with them to be paid out to the seller, and vice versa – the site essentially acting as a middleman for the trade). This adds a further layer of protection to the trade. Face-to-face is a slight misnomer. It is entirely possible never to meet the seller. If an amount is agreed, you can make a cash transfer from your account into theirs, or you can go to their local bank and make a cash deposit into theirs, and then provide them with a receipt.
Once they have this, the seller should deposit the Bitcoins with you, for storage in your Bitcoin wallet. However, genuine face-to-face trades, where you meet the individual concerned, can and do take place, every day. As with any cash transaction involving a person you don’t know, you should have consideration of your own personal security, particularly if you are looking to trade a sizeable amount. First of all, you should always arrange to meet in a busy public place. The flip-side of this, but worth repeating, is that you should never arrange to meet in a private home, no matter how good a deal you’re getting. If the seller tries to give you some reason as to why this has to happen (that his Bitcoin wallet security is set-up in a way that it has to be operated from his home machine, for instance), then politely walk away and find another seller. The potential gains for your Bitcoin portfolio are not worth the attendant risks. In short, you should take all the precautions you would normally expect to take when walking around with a large amount of cash. Now, it’s possible that the seller will not need an actual cash transaction.
An online bank transfer might be entirely acceptable to them, but they want you do do it there and then, so they can see the money going over, before they reciprocate with sending you the Bitcoins. Some sellers might even allow you to make a payment via your PayPal account, though most would be understandably reluctant to do so, preferring a non-reversible method of payment, for all the reasons mentioned earlier in this piece.
If you hope to pay by PayPal, ensure that you confirm that this is OK with the seller before meeting up, to avoid embarrassment and wasting one another’s time. Depending on the person you are trading with, they might impose a premium of between 5% and 10% on top of the current Bitcoin exchange price, to allow for the convenience and privacy of a face-to-face trade (and to compensate for their time in meeting you to conduct the transfer).
Any reputable trader should be willing to set the price before you meet, but many will institute a window of opportunity for whatever deal you strike, not wanting to wait for too long, just in case the value of Bitcoin takes a sudden and dramatic shift. It should go without saying that, if you're meeting someone for a face-to-face Bitcoin sale, you will need some way of accessing your Bitcoin wallet. If this involves bringing along your tablet, smartphone, or laptop, then so be it, but don’t forget the other essential component: a live and active internet connection to be able to confirm the transfer.
A word of caution
When considering a face-to-face purchase of Bitcoins, you would be well-advised to check that such a trade is legal in your area, before agreeing to meet. There is little reason why it shouldn’t be but, since the laws for such transactions differ from one jurisdiction to the next, it is best to be sure ahead of time. Also, there is a risk you might excite the interest of local law enforcement if you’re exchanging large sums of cash with another person in a public place. While unlikely, and easily explained, there is always the chance that a passing police officer might suspect you of trading in something a bit more illicit that cryptocurrency.
Bitcoin Meet-ups
Of course, one-to-one trades might not be your cup of tea, and that’s understandable. A popular form of direct trading in Bitcoins is the meet-up group. You can use a website like meetup.com and see if there is such a thing in your local area. The principle is the same as a face-to-face exchange, but in a group setting that allows for a greater feeling of safety among the individual attendees, and also allows you to learn more about the Bitcoin market from other members of the group.
Bitcoin ATMs
This is a relatively new concept, but Bitcoin ATMs are increasing in both number and availability across the UK. Several vendors have either released, or are experimenting with these machines: BitAccess, Genesis Coin, CoinOutlet, Robocoin and Lamassu to name but a few. The principle is simple – a Bitcoin ATM serves the same function as a face-to-face transaction, only with a machine instead of another human being. You insert your cash into the ATM and then (depending on the vendor) you either receive a paper receipt containing the relevant codes you’ll need to load your new Bitcoins into your wallet, or you receive a QR code that you will be able to scan with your mobile phone. The rate of exchange has been seen to vary wildly with these machines, and many of them add a fee for the convenience of the service, which can be as high as 8% of the transaction cost.
Other ways to purchase Bitcoins
Consumers in the States who are classed as underbanked (that is, they don’t have sufficient access to the sorts of mainstream products and financial services usually offered by retail banks), can use expresscoin, who have recently emerged to cater to this very market, accepting wire transfers, personal cheques, and money orders to pay for Bitcoins. No such service exists in the UK at this moment in time.
What countries can I buy Bitcoins from?
Bitcoin is expanding rapidly into many different markets, and it is not only possible, but expected, that a Bitcoin trader will want to buy in one market and sell in another, as the different exchanges offer different rates. With third-party organisations like CoinBase available to assist the transactions, buying Bitcoins from a different country is now easier than ever. While the spread of Bitcoin is hardly universal at this stage, every major financial centre currently operates at least one Bitcoin exchange, and analysts predict that this growth will continue into developing markets.
At present, the following countries all have a trade in Bitcoins:
Asia: Singapore
Australasia: Australia
Europe: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Finland, Greece, Hungary, Ireland, Italy, Jersey, Latvia, Liechtenstein, Malta, Monaco, Netherlands, Norway, Poland, Portugal, Republic of Ireland, San Marino, Slovakia, Slovenia, Spain, Sweden, Switzerland, United Kingdom
North America:
Canada, United States of America As with any international financial transaction, it is important to make yourself aware of the various laws and conditions that might impact on your transfer, be it your payment to the seller, or your receipt of Bitcoins from them. If in doubt, it may be worth your time speaking to, or hiring, a dedicated Bitcoin broker to make the exchange on your behalf, for a fee.
In conclusion
Buying Bitcoins is certainly not as easy as many newcomers suspect, although the ways and means by which to do so are increasing and developing all the time. As Bitcoin continues to make its presence felt in the global marketplace, the process of making Bitcoin transactions will become ever more simple, as a way of enticing developing markets, new investors, and new consumers to the currency.
2369 days ago • cryptodaily
Bitcoin’s Lightning Network Has Potential Privacy Issues
The Lightning Network is often viewed as the holy grail when it comes to scaling Bitcoin to many more transactions per second, but questions remain as to how well the current version of this layer-two network can preserve or improve user privacy. During the Scaling Bitcoin workshop at Stanford University over the weekend, Zcash co-founder Ian Miers presented on the Lightning Network’s privacy issues and a potential solution to these problems.
Privacy Issues with the Lightning Network
At first, it may appear that the Lightning Network would provide improved financial privacy by default because transactions are mostly taken off of the public Bitcoin blockchain; however, Miers explained that the aggregate payment data is really all that matters to an observer. “It doesn’t matter I’m telling you that I’m paying a psychiatrist every week for $500; it matters if you know that I’m paying the psychiatrist regularly at all,” said Miers.
Miers added that the situation does get better in a payment channel network (as opposed to a simple payment channel between two parties) because then an observer can only see a user’s entry point to the network. Having said that, Miers also pointed out that problems still exist in payment channel networks such as the Lightning Network. In short, the payment hubs or colluding nodes on the network can learn about a specific user’s transaction activity. “If you have a path in the network and all of the peers on the path collude, they can identify you,” explained Miers. “They can do this via direct collusion, [or] they can do this via correlation after the fact. You don’t really get strong privacy from this model.”
A Centralized Lightning Network May Provide Less Privacy Than Bitcoin Itself
Miers went on to explain that the privacy problems found in the Lightning Network become much worse when the topology of the network is centralized. In this situation, collusion or coordination between nodes is not necessary because the centralized node already knows everything. The level of centralization that will be found in the Lightning Network has been subject to debate since the concept was first announced.
An article exploring this debate can be found over at Bitcoin Magazine. In Miers’s view, a centralized setup would provide a level of privacy lower than what is already available via traditional payment systems. In fact, Miers went as far as to say a centralized Lightning Network would provide worse privacy than the base Bitcoin blockchain. “The situation gets a little worse for Bitcoin because it’s not likely to be some regulated or vaguely regulated entity like Visa or financial institutions, which have (admittedly thin) rules on what they can do with your personal data, [that acts as a Lightning Network hub],” said Miers. “It’s going to be: insert your favorite sketchy exchange here.” Reasons for on-chain transactions being more private than a centralized Lightning Network provided by Miers included:
The creation of multiple identities for on-chain transactions is free, while new identities on the Lightning Network require a user to lock up funds into escrow.
To gain the fee-related benefits of the Lightning Network, identities must also be long-lived.
Some Lightning Network hubs may also decide to implement policies related to Know Your Customer (KYC) and Anti Money Laundering (AML) regulations. This would mean a real-world identity is also attached to one of these long-lasting pseudonyms.
“Even if there’s not [KYC/AML], it’s a long-term pseudonym, and it’s quite easy to figure out and link these to your actual, real-world identity,” said Miers. “You use the payment channel network once to make a payment to Amazon and they ship you a product, well, now someone knows the linkage on this stuff if they collude.” Miers added that the privacy issues associated with payment channels are not even solved with something like Zcash because there are still long-term pseudonyms attached to the off-chain activity.
A Solution to These Privacy Issues
As one potential solution to the Lightning Network’s privacy issues, Miers pointed to a project called Bolt, which is based on a paper (PDF) he co-authored with fellow Zcash scientist and Johns Hopkins Associate Professor of Computer Science Matthew Green. With Bolt, Lightning Network-esque payments can be sent through intermediary nodes without revealing the participants in the transaction or their associated payment channel balances. These features are achieved through the use of zero-knowledge proofs.
“All you have to do is do a zero-knowledge proof that [says], ‘Look, this [valid signature] exists, I’m not going to tell you the balance, and here’s the new thing that differs by five dollars,’” explained Miers. According to Miers, everything about the off-chain transactions, including payment values and participants, is hidden from the blockchain. Miers added that Bolt could be added to Bitcoin or Zcash via a soft fork or hard fork through the addition of a new opcode. “The one caveat to this is that in Bitcoin you need to be able to anonymize the funding of the channel,” Miers clarified. Without an anonymous funding mechanism, the last payment associated with a particular channel can be linked to the original funding of the channel.
2369 days ago • cryptodaily
Bitcoin’s Lightning Network Has Potential Privacy Issues
The Lightning Network is often viewed as the holy grail when it comes to scaling Bitcoin to many more transactions per second, but questions remain as to how well the current version of this layer-two network can preserve or improve user privacy. During the Scaling Bitcoin workshop at Stanford University over the weekend, Zcash co-founder Ian Miers presented on the Lightning Network’s privacy issues and a potential solution to these problems.
Privacy Issues with the Lightning Network
At first, it may appear that the Lightning Network would provide improved financial privacy by default because transactions are mostly taken off of the public Bitcoin blockchain; however, Miers explained that the aggregate payment data is really all that matters to an observer. “It doesn’t matter I’m telling you that I’m paying a psychiatrist every week for $500; it matters if you know that I’m paying the psychiatrist regularly at all,” said Miers.
Miers added that the situation does get better in a payment channel network (as opposed to a simple payment channel between two parties) because then an observer can only see a user’s entry point to the network. Having said that, Miers also pointed out that problems still exist in payment channel networks such as the Lightning Network. In short, the payment hubs or colluding nodes on the network can learn about a specific user’s transaction activity. “If you have a path in the network and all of the peers on the path collude, they can identify you,” explained Miers. “They can do this via direct collusion, [or] they can do this via correlation after the fact. You don’t really get strong privacy from this model.”
A Centralized Lightning Network May Provide Less Privacy Than Bitcoin Itself
Miers went on to explain that the privacy problems found in the Lightning Network become much worse when the topology of the network is centralized. In this situation, collusion or coordination between nodes is not necessary because the centralized node already knows everything. The level of centralization that will be found in the Lightning Network has been subject to debate since the concept was first announced.
An article exploring this debate can be found over at Bitcoin Magazine. In Miers’s view, a centralized setup would provide a level of privacy lower than what is already available via traditional payment systems. In fact, Miers went as far as to say a centralized Lightning Network would provide worse privacy than the base Bitcoin blockchain. “The situation gets a little worse for Bitcoin because it’s not likely to be some regulated or vaguely regulated entity like Visa or financial institutions, which have (admittedly thin) rules on what they can do with your personal data, [that acts as a Lightning Network hub],” said Miers. “It’s going to be: insert your favorite sketchy exchange here.” Reasons for on-chain transactions being more private than a centralized Lightning Network provided by Miers included:
The creation of multiple identities for on-chain transactions is free, while new identities on the Lightning Network require a user to lock up funds into escrow.
To gain the fee-related benefits of the Lightning Network, identities must also be long-lived.
Some Lightning Network hubs may also decide to implement policies related to Know Your Customer (KYC) and Anti Money Laundering (AML) regulations. This would mean a real-world identity is also attached to one of these long-lasting pseudonyms.
“Even if there’s not [KYC/AML], it’s a long-term pseudonym, and it’s quite easy to figure out and link these to your actual, real-world identity,” said Miers. “You use the payment channel network once to make a payment to Amazon and they ship you a product, well, now someone knows the linkage on this stuff if they collude.” Miers added that the privacy issues associated with payment channels are not even solved with something like Zcash because there are still long-term pseudonyms attached to the off-chain activity.
A Solution to These Privacy Issues
As one potential solution to the Lightning Network’s privacy issues, Miers pointed to a project called Bolt, which is based on a paper (PDF) he co-authored with fellow Zcash scientist and Johns Hopkins Associate Professor of Computer Science Matthew Green. With Bolt, Lightning Network-esque payments can be sent through intermediary nodes without revealing the participants in the transaction or their associated payment channel balances. These features are achieved through the use of zero-knowledge proofs.
“All you have to do is do a zero-knowledge proof that [says], ‘Look, this [valid signature] exists, I’m not going to tell you the balance, and here’s the new thing that differs by five dollars,’” explained Miers. According to Miers, everything about the off-chain transactions, including payment values and participants, is hidden from the blockchain. Miers added that Bolt could be added to Bitcoin or Zcash via a soft fork or hard fork through the addition of a new opcode. “The one caveat to this is that in Bitcoin you need to be able to anonymize the funding of the channel,” Miers clarified. Without an anonymous funding mechanism, the last payment associated with a particular channel can be linked to the original funding of the channel.