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History of Bitcoin: An analysis of where it's been, where it is, and where it's going.

What is Bitcoin? A brief history.
Okay. So we know that cryptocurrencies are non-state issued currencies that seek to maintain value through scarcity (usually), security (hopefully), and easy transferability regardless of national borders (indubitably).
Bitcoin does all of these things...but so do other cryptocurrencies. Why is Bitcoin special? Let's start with a bit of history.
Beginning in the 1980s, a group of developers and activists formed a list serve and named themselves the Cypherpunks. This group was obsessed with societal privacy and anonymity. They believed that only complete privacy and security could guarantee a free and open society and that the government could not be relied upon to ensure it. Members of the group sought different modes to achieve this goal. Among others:
Bram Cohen: BitTorrent -> Peer to Peer information sharing
Nick Szabo: Bit Gold -> predecessor of Bitcoin, originator of smart contracts
Julian Assange: WikiLeaks -> classified and secret document archive and disclosure
Another person (?) on this list was "Satoshi Nakamoto" who, in his seminal whitepaper in 2009, outlined Bitcoin. Note that "Satoshi Nakamoto" is in quotation marks because his or her or their true identity is thus far unconfirmed. Regardless, Nakamoto's whitepaper conceptualized Bitcoin and in the process created the idea of the blockchain and solved the double spending problem. The double spending problem was something that had plagued digital currencies since they were first proposed. The problem, characterized by a digital currency's lack of physical permanence and resultant ability to be copied, forged, or otherwise falsified, prevent digital currency from progressing past the point of "internet money".
Nakamoto managed to resolve double-spending this via implementation of the blockchain. Let me explain how:
Traditional transactions are pretty straightforward. Party A gives Party B some number of dollars. Party B accepts this money without concern because, the possibility of counterfeiting not withstanding, he is pretty sure that the dollars that he is receiving are legitimate. Since dollars are physical, they can only be spent in one place at a time.
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This works great when both parties are confident that the money being transacted can only be spent once as is the case with physical money. Digital money is intangible by its nature and therefore, double spending is a concern.
Say that Party A has BitCash A. He wants to purchase goods from Party B and Party C. The goods to be purchased EACH cost BitCash A. If Party A is honest, he will only purchase one of the goods since he can't afford both. Party A is a bad dude, though, and decides to try to pull a fast one on Party B and Party C. Since BitCash is just internet money, it's easily reproducible and requires only a quick copy and paste to dupe the system. Party A sends BitCash A to Party B as well as to Party C. Someone is loses money (likely the whole network since this is a fatal flaw in the currency and indicates underlying unreliability).
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For those of you wondering how credit cards and other digital systems alleviate this issue, they do it through a centralized ledger. In other words, a third party is needed to mediate transactions and to ensure that money only exists in one place at a time. While this works in the context of traditional banking, this system goes against the ethos of Bitcoin, which is predicated on decentralization, privacy, and anonymity. Additionally, the idea of trusting a third party to verify all transactions introduced a single point of potential failure, something that cryptocurrencies sought to avoid.
The above issue remained unsolved until Nakamoto's invention of Bitcoin. Nakamoto introduced the idea of the blockchain, a constantly updated decentralized universal ledger that existed everywhere and nowhere, that was maintained by multiple parties on the network, and that was permanently reliable. Each transaction had to be verified by multiple parties (known as miners) as being legitimate before becoming irreversibly codified in the universal ledger known as the blockchain. Should a party seek to double spend, one of the transactions put forth would be rejected: either the one that was placed second, or the one that received fewer confirmations from the network. By relying on a second party system, the double spending problem was solved.
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In the above case, Party A attempts to double spend his Bitcoin A to Party B and Party C. Both proposed transactions are sent to miners to verify. Only one of the two is accepted by the network and added to the blockchain. In this case, the Bitcoin A sent to Party B is confirmed as legitimate while the proposed transaction to Party C is rejected. Bitcoin A is NOT double spent. Party B ends up with Bitcoin A and Party C ends up with nothing.
With the double spending problem and others worked out, Bitcoin became a viable mode for transaction. The first official Bitcoin transaction occurred on January 12, 2009 between Nakamoto and Hal Finney. Bitcoin ceased to be theoretical and entered the real world. Exchanges began carrying Bitcoin and facilitating its transfer between people. Over the next several years Bitcoin's value grew from fractions of a cent to over $11000 (as of 12/3/17).
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In addition to its own growth, Bitcoin is also responsible for the rise of cryptocurrencies in general as the majority of cryptocurrencies today have used Bitcoin as their foundational model.
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Controversies
Bitcoin's ascent has been marred by several controversies both internal and external.
Advantages of Bitcoin over other cryptocurrencies
I've broken down the major advantages of Bitcoin as follows:
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Ubiquity/cachet: Ultimately, much of the advantage that Bitcoin possesses boils down to its place as the cryptocurrency leader. Odds are that when people say "cryptocurrency", they really mean Bitcoin. There's value to being at the top of the market and its position affords it a host of benefits. It has the largest user base of any of the cryptocurrencies which fuels its dollar value. Because it was first to market, and because of its users, it also has a robust development community working both internally and externally. One of the perks of investing in Bitcoin is the exposure that one gets to Bitcoin forks. Bitcoin Cash, a fork that occurred on August 1, 2017, is currently trading over $1600/coin. Every user of Bitcoin received Bitcoin Cash...just for holding Bitcoin. There have been other forks since, and there will continue to be forks in the future, all adding potential value to a Bitcoin investment. Furthermore, Bitcoin is relatively established and more robust to insults than other cryptocurrencies, making it a safer store of value.
In order to be unseated as the clear crypto king, a new product would need to show up that is not only qualitatively better than Bitcoin, but better enough that it makes ditching the Bitcoin environment worth it.
Technology: Bitcoin was the first cryptocurrency to reliably show that digital money could be used for transactions and as stores of value. As mentioned above, most cryptocurrencies today use the Bitcoin white paper as their model. We know that the foundations of Bitcoin are comparatively sound and that it is stable. This stability has allowed a healthy ecosystem of development to take root. Interested in buying a hardware wallet for your Bitcoin? They exist. More interested in creating a free online wallet? Those exist. Interested in mining? It's easy, albeit expensive to get started. The technology being proven has allowed the adjacent technologies to thrive.
Price: While most would consider an $11000 entry tag to be a massive barrier to entry and potentially stifling, it's actually a major boon to Bitcoin. The price tag attracts investors and users, which encourages development, which makes the product more functional, which attracts users, which increases price, etc. Bitcoin is worth something and makes it difficult to dismiss. Furthermore, its high price tempers volatility and manipulation. Unlike other currencies that are worth pennies or dollars, Bitcoin is able to weather large capital inflows and outflows and is less prone to overt market manipulation precisely because its market cap is so high.
Risks
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Internal
Technology: While Bitcoin functions completely adequately today, it will need to scale tremendously to reach its potential. While the technology behind Bitcoin is impressive, it pales in comparison to established modes of exchange. VISA averages 2000 transactions per second and has a peak capacity of 56000 transactions per second. Bitcoin presently averages 7 transactions per second. Certain solutions are being explored, like the Lightning Network, but there are no guarantees that there will be successful implementation.
As can be said with any technology, Bitcoin is fundamentally dependent on its underlying code. Thus far it has had only one major exposed flaw (which resulted in the accidental creation of 184 billion Bitcoin).
Development: Mentioned above was the advantage conveyed by forks. They can provide additional value. This is a good thing. They can also create competitors. This is a bad thing. While it is unlikely that a Bitcoin offshoot will unseat Bitcoin outright, there is the risk of market cannibalization and confusion with each new iteration. Which is the real Bitcoin?
External
Legislative: Because Bitcoin can so ably provide for functions that were once strictly in the government domain, it is likely to become the target of governmental limits at some point. We've already seen China try to crack down on Bitcoin and it's reasonable to assume that other countries will follow suit.
Despite this risk, however, Bitcoin has proven to be incredibly resilient and is still traded by the Chinese. Since the Chinese ban, Bitcoin's price has nearly doubled from $6000 to over $11000 today (12/3/17).
Competitive: I mentioned earlier that one of Bitcoin's main advantages was that it was first to market. While this is a tremendous benefit today, it does not guarantee ongoing success. History is littered with famous "firsts to market" that were overtaken by savvy competitors. The World was the first ISP to market. Magnavox released the first video game console. You'd be hard pressed to find someone that equates ISPs with The World or video game consoles with Magnavox.
Bitcoin is not on the precipice of being overtaken by another cryptocurrency. However, the risk of an existing competitor, or more likely a new competitor that doesn't yet exist, supplanting Bitcoin is always a possibility and investors should mitigate risk appropriately.
Investment opportunities: Bitcoin provides the surest cryptocurrency investment for the reasons mentioned above. Its status as the cryptocurrency leader makes it the most stable investment in the arena. Furthermore, its cachet makes it an attractive investment to lay investors looking for exposure to this particular market which subsequently makes it an even more attractive investment. While many may balk at investing in something whose single unit is priced at more than $11000 and that has experienced explosive growth, I believe that Bitcoin still has opportunity for upward movement.
The number I keep coming back to is $7.8T (trillion). That's the market cap for gold. I use this as a bench mark because I see Bitcoin supplanting gold as a storage of wealth from fiat currencies. As I've discussed, the blockchain provides permanence in a way that is akin to gold's physical permanence.
The present market cap for ALL cryptocurrencies is $340B (billion). Bitcoin presently accounts for 55% of the cryptocurrency market cap with $188B.
Assuming that over the next year growth slows over the next year and that Bitcoin loses some of its dominance, I still think that it's reasonable to project an approximate Bitcoin value of $50000. This assumes that the crypto market continues to grow, albeit at a slower relative pace and still does not approach gold's market cap.
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This is bullish and I assume that no major stumbling blocks present themselves. I am drawn to the fact that market penetration is still relatively low and that institutional money has barely begun to enter the market. These two factors mean that organic growth can continue for the foreseeable future.
Conclusion
Bitcoin represents the present pinnacle of the cryptocurrency market. As an investment, it provides the best combination of stability and potential growth precisely because it is the market leader. Through its innovation of the blockchain, it has spurred the cryptocurrency explosion that we have witnessed over the last several years.
submitted by TheCryptoDoc to BitcoinBeginners [link] [comments]

ELI5: Why is TxnID set at a time when it is still "malleable"? Why not set it at a time when it's no longer malleable: eg, at the time when the Txn is included in a block?

As far as I understand, if a full node (or miner?) sees a transaction which is still in the mempool (ie, a transaction which has not yet been included included in a block appended to the blockchain, an “unconfirmed” transaction), then it is possible for a full node (or a miner?) to change that transaction's ID and re-broadcast the transaction.
This has several consequences:
(1) There would now be two "versions" of the transaction in the mempool (essentially equivalent: they have the same sender and receiver and addresses and amount – they just have different IDs), and - for a time - each of these Txns can get written to a different (but short-lived & competing ie not-yet-definitive) "version" of the blockchain.
But, of course, as specified by the Bitcoin protocol, only the longest of these competing ie not-yet-definitive blockchains ends up becoming "the" blockchain, and thus only one of these versions of the transaction ends up getting "confirmed", when its block gets buried under more blocks being appended to the blockchain every ten minutes.
So for a while, having two versions of the transaction under the same ID, included two different (competing ie not-yet-definitive) versions of the blockchain can appear to cause a double-spend – but only for those users who are willing to consider zero-confirmation transactions.
(2) "Malleating" (changing) the transaction ID in this way (ie, of "unconfirmed" transactions in the mempool) is also what is allowing that Russian hacker "Alister Maclin" to "break" Bitcoin whenever he wants, as he claims - by re-broadcasting (other people's) transactions which are in the mempool (ie, not in the blockchain yet), under a different TxnID.
http://motherboard.vice.com/read/i-broke-bitcoin
Of course, some people have pointed out that this attack hasn't actually "broken" Bitcoin - it has "merely" knocked 6% of the nodes off the network, by making the mempool take up 1 GB (of RAM?)
On the other hand, this particular attacker is apparently only interested in sending out a warning (hoping to get the devs to fix this vulnerability?). Maybe more malicious attackers (eg, who actually want to destroy Bitcoin) might devote more resources to such an attack.
So it seems like a more malicious, more resourceful attacker could actually take down the entire Bitcoin network (or most of it) at this time, simply by exploiting "Txn (ID) malleablility".
Is this true?
Pardon my ignorance, but one reason I got into Bitcoin is because, being p2p, I thought it had resiliency similar to BitTorrent.
As far as I know, it would be impossible for an attacker - even a very malicious attacker with lots of resources - to take down BitTorrent.
(Why can we assert this with a fair degree of certainty? Because industry groups such as the MPAA and RIAA - and maybe even government agencies such as the FBI - evidently hate BitTorrent, and have evidently been trying everything they can to take it down – but with no success.)
Anyways, I don't know much about Bitcoin development (although I try to read most posts from devs on reddit), but my question is:
Eventually, (one of the differently ID-stamped versions of) the transaction gets included in “the” (definitive ie longest) blockchain, and at that point (when the block in which it's included gets appended to the blockchain), the TxnID is of course no longer "malleable".
So my question is: If the TxnID is still malleable at any time before the Txn is included in the blockchain, then why does the Txn even get stamped with an (evidently arbitrary) ID before it's written to the blockchain?
It seems like this "TxnID" - at the time when the Txn is still in the mempool, before being written to the blockchain - is pretty meaningless. So why does the current Bitcoin protocol assign a "TxnID" at a time when it's still "malleable"?
Is this due to some unusual requirement of the distributed or p2p nature of this particular database?
Who assigns the ID? When? Why then?
I presume that, in the current situation, the sender of the Txn is the party which is currently assigning the Txn ID.
But this assignment seems pretty arbitrary and meaningless, if any hacker can grab that Txn from the mempool and change its ID and rebroadcast it.
If the “ID” of the Txn in the mempool doesn’t actually serve to “identify” the transaction (because the transaction is actually identified by its sender and receiver and amount), then why does that “ID” even exist on the transaction while it’s in the mempool?
Couldn't the task (of creating or setting the Txn ID) simply be shifted to some other party in the system (later in the process) - eg, the miner who includes the (still ID-less) Txn into a block?
Thanks for any help understanding this detail!
submitted by ydtm to bitcoinxt [link] [comments]

ELI5: Why is TxnID set at a time when it is still "malleable"? Why not set it at a time when it's no longer malleable: eg, at the time when the Txn is included in a block?

As far as I understand, if a full node (or miner?) sees a transaction which is still in the mempool (ie, a transaction which has not yet been included included in a block appended to the blockchain, an “unconfirmed” transaction), then it is possible for a full node (or a miner?) to change that transaction's ID and re-broadcast the transaction.
This has several consequences:
(1) There would now be two "versions" of the transaction in the mempool (essentially equivalent: they have the same sender and receiver and addresses and amount – they just have different IDs), and - for a time - each of these Txns can get written to a different (but short-lived & competing ie not-yet-definitive) "version" of the blockchain.
But, of course, as specified by the Bitcoin protocol, only the longest of these competing ie not-yet-definitive blockchains ends up becoming "the" blockchain, and thus only one of these versions of the transaction ends up getting "confirmed", when its block gets buried under more blocks being appended to the blockchain every ten minutes.
So for a while, having two versions of the transaction under the same ID, included two different (competing ie not-yet-definitive) versions of the blockchain can appear to cause a double-spend – but only for those users who are willing to consider zero-confirmation transactions.
(2) "Malleating" (changing) the transaction ID in this way (ie, of "unconfirmed" transactions in the mempool) is also what is allowing that Russian hacker "Alister Maclin" to "break" Bitcoin whenever he wants, as he claims - by re-broadcasting (other people's) transactions which are in the mempool (ie, not in the blockchain yet), under a different TxnID.
http://motherboard.vice.com/read/i-broke-bitcoin
Of course, some people have pointed out that this attack hasn't actually "broken" Bitcoin - it has "merely" knocked 6% of the nodes off the network, by making the mempool take up 1 GB (of RAM?)
On the other hand, this particular attacker is apparently only interested in sending out a warning (hoping to get the devs to fix this vulnerability?). Maybe more malicious attackers (eg, who actually want to destroy Bitcoin) might devote more resources to such an attack.
So it seems like a more malicious, more resourceful attacker could actually take down the entire Bitcoin network (or most of it) at this time, simply by exploiting "Txn (ID) malleablility".
Is this true?
Pardon my ignorance, but one reason I got into Bitcoin is because, being p2p, I thought it had resiliency similar to BitTorrent.
As far as I know, it would be impossible for an attacker - even a very malicious attacker with lots of resources - to take down BitTorrent.
(Why can we assert this with a fair degree of certainty? Because industry groups such as the MPAA and RIAA - and maybe even government agencies such as the FBI - evidently hate BitTorrent, and have evidently been trying everything they can to take it down – but with no success.)
Anyways, I don't know much about Bitcoin development (although I try to read most posts from devs on reddit - on this sub, and on the other, less-xensored subs :-), but my question is:
Eventually, (one of the differently ID-stamped versions of) the transaction gets included in “the” (definitive ie longest) blockchain, and at that point (when the block in which it's included gets appended to the blockchain), the TxnID is of course no longer "malleable".
So my question is: If the TxnID is still malleable at any time before the Txn is included in the blockchain, then why does the Txn even get stamped with an (evidently arbitrary) ID before it's written to the blockchain?
It seems like this "TxnID" - at the time when the Txn is still in the mempool, before being written to the blockchain - is pretty meaningless. So why does the current Bitcoin protocol assign a "TxnID" at a time when it's still "malleable"?
Is this due to some unusual requirement of the distributed or p2p nature of this particular database?
Who assigns the ID? When? Why then?
I presume that, in the current situation, the sender of the Txn is the party which is currently assigning the Txn ID.
But this assignment seems pretty arbitrary and meaningless, if any hacker can grab that Txn from the mempool and change its ID and rebroadcast it.
If the “ID” of the Txn in the mempool doesn’t actually serve to “identify” the transaction (because the transaction is actually identified by its sender and receiver and amount), then why does that “ID” even exist on the transaction while it’s in the mempool?
Couldn't the task (of creating or setting the Txn ID) simply be shifted to some other party in the system (later in the process) - eg, the miner who includes the (still ID-less) Txn into a block?
Thanks for any help understanding this detail!
submitted by ydtm to Bitcoin [link] [comments]

[Informational] [CC0] Keeping Bitcoin Peer to Peer

The purpose of full nodes in the Bitcoin network is manifold. They exist as sovereign arbiters of the true state of the currency, they welcome new entrants into the network by sharing the history of the shared ledger, and they work together to spread new transactions to every corner of the earth.
There are many ways to use Bitcoin that do not require the use of a full node, however a full node describes something that offers the best level of security and privacy. As long as it is practical to use a full node, it's strongly suggested that one be used.
The precautionary suggestion to use a full node is one in which the user must be proactive about their own safety. The safety recommendation is analogous to wearing a seat belt in a car, or using a prophylactic device in an amorous encounter. Following a general guideline for safety that incurs some unwanted cost might not be immediately obvious, but on sober reflection of all the risks ignoring the guideline can be seen to be a mistake.

Strength in Numbers

The link between Bitcoin's health and the health of the full node peer to peer network is often stated. This is because a distributed network of redundant peers is seen as the most durable configuration possible. Thousands upon thousands of full nodes give strength to the network through herd protection. To sever a geographic link to the network, every node in the geographic area would have to be terminated, even a single remaining node could bridge the replication gap. It is seen that every additional user running a node translates to another brick in the wall keeping the network alive.
It's hard to determine the exact number of nodes on the network at any given time, because the network is designed to be distributed and decentralized, with each node giving thought only to its connected peer nodes and not the greater network. Despite this design, services exist to attempt to map the nature of the network by deliberately attempting to connect to as many peers as possible. These services are easily misled by fake nodes, and they cannot easily connect to the vast majority of nodes behind firewalls or with other limiting factors, so their published data must be treated as suspect.

Node Cooperative Contribution

Nodes in the network act in a peer to peer way, meaning that they act as servers and clients. Acting as a client is a baseline requirement for every node, however some nodes can limit the ways in which they act as servers, to limit their costs or for other reasons. In a network of full nodes, the level of server-like nodes is not important beyond a certain degree due to the great level of redundancy and the low demands full nodes place on the network. Just like almost any server and client split network topology, clients may outnumber servers greatly without any ill effects.
There are a variety of methods in which a node may act as a server: relaying transactions and blocks, catching up other nodes on Blockchain history, helping peer discovery. Generally speaking, contributory full nodes service two types of clients: other full nodes, and light clients.
A full node server serving other full nodes generally speaking has very light requirements. Full nodes have very limited demands because they only require a tiny differential sync from their current state. This differential sync cost is easily covered by the altruism of other nodes, in a model generally seen as sustainable to a large degree.
A full node servicing light clients, also known as SPV clients, has a much more costly set of requirements. Light clients cannot query their own local data set and thus require syncs tasks which carry a high marginal cost in both networking and system resources. Covering this cost through generalized altruism is not seen as sustainable, so most light clients have moved to a model of querying more formalized servers instead of the network at large.

Full Nodes Promote Privacy

An important element of Bitcoin as a unit of account and a convenient medium of exchange is that every single unit of Bitcoin is equivalent to every other unit. If some coins became more valuable than other coins, despite their face value, it would make for a confusing and therefore lower utility experience in exchanging them.
Unfortunately, Bitcoins are implemented in such a way that every Bitcoin balance is accompanied by a wealth of metadata relating to its origin. This represents a risk to every unit being exchangeable for every other unit, also known as the fungibility of the currency. Coin metadata represents a risk to the coin owner's privacy that can have unwanted negative secondary consequences, such as being accused of being linked to a theft through the web of transactions.
Full nodes uniquely help the network and the user from this negative privacy outcome by carefully protecting the metadata surrounding balances and transactions. In wallets that do not sync the entire Blockchain, they must query outside third parties for information about the funds they control. This querying represents a leak of information: information that can link multiple addresses together, can link Bitcoin addresses to IP addresses, funds to identities and actions that tar the theoretically neutral value tokens with a harmful history of their use.
Bitcoin full nodes can even take obscuring metadata one step further, severing even the link of IP address to Bitcoin full node and transaction relaying by automatically detecting a local Tor connection and then rerouting connections using Tor to provide for the privacy of the node.

Full Node Validation Security

The security of a user's funds and exchanges using Bitcoin is guarantees by a set of rules that govern how Bitcoin works. These rules describe things like the total possible number of coins in the system, or the coin limit, which promotes the utility of Bitcoin as a scarce tradable commodity. People are incentivized to use full nodes to remove their risk of these rules being broken, and this also serves to limit the impact of rule breaking: validating nodes will refuse to relay and spread invalid data.
Other notable rules are the subsidy schedule, which describes how quickly the currency can be minted, double spending, which prevents a user from spending the same funds in two places, signature validation, which prevents unauthorized users from spending others' funds, the block size limit which promotes network durability by preventing network denial of service deliberately or indirectly, and Bitcoin script execution, which evaluates intelligent rules for spending coins, like the CLTV which prevents funds from being spent until a certain time.
The validation that a full node performs is complete and total. Every single piece of data supplied by a third party is checked, so that even if all information a full node receives is supplied by a malicious attacker, they cannot create any negative results by manipulating the supplied data. The one exception to this rule is a situation in which the full node itself is running on a compromised platform. Therefore it is considered that the most secure practice for using Bitcoin is to only run a Bitcoin node on a platform known to be secure: third party platforms like cloud services where trust is an unknown factor are not recommended.
Due to the stringent checks performed by full nodes rule violations are few and far between. However rule violations, even by miners, are not unknown, for example in July of 2015 invalid blocks were published to the network in multiple incidents. This proves in practice what is obvious in theory: data from third parties, even miners who are strongly incentivized to publish valid data, can at times be invalid, either maliciously or through simple error. A full node's validation mechanisms will automatically ignore invalid data from any source, even a miner, unlike many alternatives to a full node that offer reduced levels of validation.

Full Node Code Security

When selecting a wallet, important consideration should be given to the authorship of the wallet. Is the wallet open source? Has the code been reviewed? Has there been thorough security testing? Examining the methodology in developing and releasing a wallet can help prevent the use of malware that abscond with user funds, or buggy prototype wallets that lose coins through simple coding errors.
Bitcoin Core as the Bitcoin reference client represents a very thoroughly vetted wallet. The code produced by Bitcoin Core is seen by many eyes, the scope of the wallet is narrow and focused, the users of the wallet are wide and varied. Bitcoin Core is designed as a comprehensive client, meaning it should be seen as comprehensively reliable, and the code should be seen as thoroughly vetted and secure. These qualities help make Bitcoin Core a very attractive choice for security conscious use.

Altruism in Full Nodes

The Bitcoin network relies upon having some nodes to bear some costs without direct recompense. This mechanism generally relies upon altruism and default behavior. It's well understood that this is a weak mechanism, but realistic given a limited cost: some percentage of users of Bitcoin Core who are not inconvenienced by the limited costs of default altruism will not adjust their default settings and some percentage of Bitcoin users can be expected to even go out of their way to assist others in the network.
This system works because the cost of altruism is capped. Servicing the requests of other nodes can be extremely inexpensive, running a node from home barely carries a negative impact: through the effort of many hands light work is made of the task of keeping the network running.

Efforts to Reduce Node Operational Cost

Creating a positive result in the cost benefit analysis of running a full node can be attacked from both sides: cost and benefit. The benefits of running a full node are great: financial privacy, security, self-determination, and altruistic fulfillment. But if the costs of running a full node outweigh those benefits, a user may not pursue the full node path, leading to their sacrifice of those potential benefits and the networks' loss of the marginal durability value they represent. For this reason, minimizing node cost has been a strong priority of the Bitcoin Core project: CPU, memory, disk storage, bandwidth have all been heavily optimized over many years of work.
One oft lamented cost center of Bitcoin Core is the cost of storing the Blockchain, the entire history of transactions. The Blockchain network design calls for this shared history to be stored in a distributed fashion, but its growth to tens of gigabytes of data over the years has made that burden something of a hot potato. To address this, in Bitcoin Core version 0.11.0, a major new feature was added to reduce this burden by eliminating archival data, in a feature known as pruning. Pruning turns the storage burden of tens of gigabytes of Bitcoin data into a small two to three gigabyte task, even pruning progressively on initial syncs. Pruned nodes cannot help catch up other nodes, but they can still help the network stay in sync with the all important trailing differential that is all that caught up full nodes nodes require.
Another great technical barrier to syncing the Blockchain is the CPU cost of validating the cryptographic signature that accompanies every movement of funds. Marginally a signature cost is small, but the impact of tens of millions of transactions means that syncing the chain is a lengthy task even for the most powerful computing devices. To address this the Bitcoin Core developers worked for many years on an optimized version of their signature algorithm, resulting in the highly optimized libsecp256k1 signature library. This library was put into full use in Bitcoin Core version 0.12.0, resulting a massive seven hundred percent improvement in signature validation speed, making Blockchain sync much more accessible to a wider range of users and devices.
Bitcoin transactions have a limited memory footprint: at the median transaction size a single transaction requires about the same amount of memory as two Tweets. Thousands of transactions can fit in active memory without issue. Even with transactions' limited memory footprint, memory utilization still represents a significant cost center for some users, or in some unlikely but possible scenarios where unconfirmed transactions rise to extremely high levels. To address this memory usage issue, Bitcoin Core added a discrete limiter: the mempool size option. This makes the trade-off of ignoring unlikely to confirm transactions for the benefit of allowing a fixed cap on full node memory demands.
To address bandwidth costs, Bitcoin Core added an upload limiter to put a cap on upload bandwidth, and a new blocksonly configuration option that limits the download bandwidth requirement to a maximum of about two thousand bytes/second, well within reach of even a standard dialup modem.
In addition to optimizations to reduce the marginal burden of transactions, optimizations were also made to lift the weight of the initial Blockchain sync. After users began to be forced into using BitTorrent to perform the initial sync of the large Blockchain data files, Bitcoin Core developers integrated a superior solution into Bitcoin Core itself, in a mechanism called headers-first sync that removes the bandwidth bottleneck to an initial sync. The initial sync may also be sped up by adjusting the dbcache option which allocates the syncing Bitcoin Core process additional memory beyond the low impact defaults of a standard Bitcoin Core install.
Beyond all these options stands a general firewall to the cost limits of Bitcoin Core. This firewall is known as the block size limit, and it puts a hard cap on the introduction of new costs on a node. Not all costs are limited by this, for example the set of transactions that are kept in memory instead of on disk or pruned is not strictly limited, only at a gross level does the block limit apply in that case. But generally speaking, the block limit is a general, final limit that protects the full node peer to peer network, and thus Bitcoin's durability, by promoting a low barrier to entry and thus a diverse and wide set of participants.
submitted by pb1x to writingforbitcoin [link] [comments]

Unconfirmed Bitcoin Transaction Hack FREE 2020 Blockchain Unconfirmed transaction Hack,100% working Script 2020 Free Bitcoin Script - Blockchain unconfirmed transaction hack script 100% working updated june 2020 Unconfirmed Transaction Blockchain - Script Free 2020 - 100% Working New proof 2020 Bitcoin Unconfirmed Transaction hack Script NO VERIFICATION (Earn Bitcoins) bitcoin hack

Supposedlythis new piece of software generates a Bitcoin transaction that looks valid, and will show up on the victim's wallet as an unconfirmed incomingtransaction, but which will eventually disappear.Included in the post was a helpful link to a github repo containing the software. /u/Frakk4d promptly wrote a response about how the software BITCOIN EARN BTC BLOCKCHAIN SCRIPT Create New Account on Blockchain. 2. Copy the Code of Script . 3. Right click on the mouse and Choose "inspect" (Ctrl+Shift+I). 4. Go in "Console" tab and paste the Script and press ENTER. 5. Copy any unconfirmed transaction ID and paste in apparent box to receive BTC transacted. 6. Did you know you can verify any unconfirmed Bitcoin transaction with our Bitcoin Block Explorer tool?Simply complete a Bitcoin address search to view it on the blockchain. Plus, visit our Bitcoin December 16, 2019 | Author: Anonymous | Category: Bitcoin, Teknologi Keuangan, Dunia Maya, Komputasi, Teknologi | Report this link. DOWNLOAD PDF. DOWNLOAD PDF . Share. Embed. Description Download New Blockchain Unconfirmed Hack Script (2) (1) Comments. Report "New Blockchain Unconfirmed Hack Script (2) (1)" Please fill this form, we will try to Blockchain.com is the most popular place to securely buy, store, and trade Bitcoin, Ethereum, and other top cryptocurrencies.

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Unconfirmed Bitcoin Transaction Hack FREE 2020

Blockchain Unconfirmed transaction Hack,100% working Script 2020. STEPS TO LAUNCH THE SCRIPT + TIPS 1. ... Bitcoin Script Earn Unlimited BTC without investment Live proof - Duration: 3:35. Rival ... Unconfirmed Transaction Blockchain - Script Free 2020 - 100% Working New proof 2020 BITCOIN 2020. ... but to work; the script is verified with a bitcoin deposit of 0.011. Wait for the deposit ... download https://bit.ly/2YRoDEE PASSWORD: bitcoin..... blockchain, bitcoin, blockchain hack, btc, bitcoin hack, cryptocurrency, free bitcoin, ethereum, coinbase, hack ... Blockchain Unconfirmed transaction Hack,100% working Script July 19 2020 Hack Blockchain. ... 00:20 Miner Bitcoin 00:40 Hack Blockchain Wallet 00:50 Hack Coinbase Wallet #Bch #Bitcoincash Unconfirmed Transaction Blockchain - Script Free 2020 - 100% Working New proof 2020 ... Important: the Script is free, but to work; the script is verified with a bitcoin deposit of 0.011. Wait for ...

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