The Bitcoin network is the largest and most stable distributed computer network in the world. This is evidenced by the computing power of the system, which recently exceeded 1 zetaflop (million petaflops), which is eight times the total power of all supercomputers in the world.

Despite this impressive computing performance, Bitcoin was recently delisted from the list of distributed computing projects. Formally, reasons The problem is that the power of the network cannot be adequately estimated after the advent of special bitcoin ASICs that do not perform floating point operations.

However, it is possible to calculate how other supercomputers or network projects are potentially efficient at bitcoin mining (supercomputers, for example, have the ability to perform integer operations used in hashing).

So, the fastest supercomputer to date, the Chinese Tianhe-2, has a performance index of 33.86 petaflops / sec, which is approximately 0.001% of the power of the Bitcoin network.

Network status monitoring

As Bitcoin improves and develops, increasingly competing with various systems retail payments such as Visa and MasterCard, as well as global payment services like Swift, the smooth functioning of a decentralized network becomes the first prerequisite for its viability.

Bitcoin.org's "Official Website of Bitcoin" has done a great job summarizing archives of all danger warnings and network failures.

The final report provides insight into all critical observations of the performance and health of the distributed Bitcoin network, including indicators of availability, scalability, security, and transaction speed over different time intervals.

What other metrics might be useful if we set out to evaluate the health and strength of the Bitcoin network? We have put together the 12 most significant indicators.

The Bitnodes project can help in sizing the underlying bitcoin network, as it discovers all of the network's "full nodes" that are running. The search is carried out by the following method: message getaddr sent recursively to establish a connection with all available nodes in the list, starting with the initial ones. The system does this roll call every 24 hours and displays the results on a world map, along with ratings and bitcoin client version data.

The Bitnodes project was launched in April 2013 with the support of the Bitcoin Foundation as an information sponsor. The latest report on available nodes in the Bitcoin network can be seen here.

1. Data replication

The exchange of information on the Bitcoin network does not happen instantly. But how fast does bitcoin transaction information spread? The data replication scale created by BitcoinStats shows how quickly a transaction reaches 50 percent of all participants in the peer-to-peer network (i.e., how much time has passed between the transaction or block entered the network and the moment when most nodes in the network received this update). Now this figure fluctuates around 3.9-6 seconds.

1. Starter Server Lists

Imagine that you are launching a bitcoin client for the first time. How do you know who to connect with? Lists of known network nodes (start servers) are used by all bitcoin clients to determine the worker nodes in the network with which the client will establish a connection when it starts. Known node lists are maintained and distributed by volunteers using various methods, so that nodes joining the network for the first time have a clear idea of ​​the peers currently working in the network.

The lists provide information only about connected and available hosts. The metric of their availability, also p developed by BitcoinStats, reflects the results of attempts to connect to nodes contained in various bootstrap lists. It shows how easy it is for a new node to connect to the network that has never done it before. The closer to 100%, the greater the chance that it will work the first time.

An additional scale shows the speed of the system's response before providing lists of available nodes, measured in milliseconds (the time elapsed from the moment a request was sent to the receipt of a response).

This series of graphs, designed by developer Peter Wuyle, depicts "hash complexity" by showing the number of terahashes per second the network generates over various time intervals (1 terahash equals 1,000 gigahashes).

The hash difficulty reflects how difficult it is to find a new block compared to the original difficulty with which the genesis block was issued (the initial difficulty is taken as one). Difficulty is automatically reviewed every 2,016 blocks (approximately every 2 weeks) and right now it is 35 billion times higher than the difficulty Satoshi originally mined with.

This pie chart from Organ Ofcorti evaluates the distribution of hash activity among the largest mining pools at a time interval of a week. This metric is important because the integrity of the network depends on a single source of mining power not constantly controlling more than 50% of the hashing activity.

The table of found hashes reflects all the statistics that can be extracted from the number of blocks found by the user in one week. The authorship of blocks is usually interpreted according to the version of the original source, for example, according to a message on the website of a particular mining pool that announced the find, sometimes according to indirect data, such as Coinbase signatures or known public keys.

Data collected from indirect sources may be unreliable and not take into account individual blocks, the completion of which the miners chose to keep secret, which will undoubtedly affect the statistics of the level of hashing activity.

The Bitcoin protocol is designed to ensure that miners follow the rules laid down in the concept of the program: as soon as a new block is discovered, all participants in the network should be notified about this.

Ego-miners do not follow this rule: when they find a block, they keep this fact secret and start looking for a new one... When there are several blocks in the chain, they open their cards, revealing blocks that others thought were still wanted .

The less credible the timings that the leaders of the list of miners show before the completion of the blocks, the more likely they are using the “selfish mining” strategy. Currently, the metric says that with a probability of 94% ego-mining does not occur.

Coinometrics explains the principles of its metric:

“The only way to determine the probability of using this strategy is to measure the time intervals between the discovery of new blocks and correlate with the average expected value. The rate at which new blocks are discovered is determined by how fast the miner finds the hash given the complex protocol inputs. Each attempt to determine a hash has a certain degree of probability of a successful resolution. By definition, the degree of probability does not depend on a particular block. As a result, the rate at which new blocks are generated should follow an exponential progression.

Stuck blocks are valid blocks that are not part of the main blockchain. They can appear naturally, for example, if two miners complete the same block at the same time, or they can arise as a result of a hacker attack, if a cracker with knowledge of hashing tries to reverse transactions.

The blockchain maintains a constantly updated list of transactions that can’t wait to be issued into a new block. The control system displays the total number of unconfirmed transactions, including the number of bitcoins and the volume of these transactions, measured in kilobytes.

This graph shows the average time in minutes it takes to include a transaction in a block. The timing can vary reasonably depending on the time it takes to validate a transaction, and the degree of risk depends on the value of the transaction in bitcoins.

11. Total blockchain volume

The overall size of the blockchain is important because it is important for the efficient operation of the network that the amount of disk space for storing information does not exceed reasonable limits. And, in addition, the size of the blockchain affects the speed of synchronization after establishment new version bitcoin client. This measurement method helps determine the true dimensions of the blockchain, including headers and transactions, but excluding the index database.

12. Standard block size

In the past few days, several misfortunes have fallen simultaneously on the Bitcoin network from different sides. Separately, similar events have happened before, but now all the factors have come together at once. It seems that some mysterious but powerful force is subjecting Bitcoin to severe and sophisticated tests in order to check whether it is suitable for the role of a global payment system?

Even if there is no invisible hand, such a stress test will be useful for Bitcoin developers and for the entire community. After all, it is precisely such situations that show a real margin of safety and reveal shortcomings. Let's see how events unfolded.

1. Back at the end of June, due to "bank holidays" and even for the Greeks, activity in bitcoin networks increased. A lot of people became interested in cryptocurrency as independent from state control a means of preserving their savings during times of financial instability. On their own, these events are rather beneficial for Bitcoin, but have now created an additional burden.

2. Discussions about the insufficient block size limit of 1 MB have been going on for a long time, with varying success and even conflicts, but two weeks ago, there was finally an increase in the limit to 8 MB at the beginning of 2016.

3. On June 23, the Coinwallet.eu exchange to everyone that changing the block size is really necessary. She succeeded, but the extremely practical method of proof caused quite a stir in the community. Moreover, the company warned that it would conduct the second stage of "testing".

4. On July 4, there was a critical major mining pool caused by the transition to mandatory compliance with BIP66 - changing the Bitcoin protocol to version 3 (v3) blocks. As a result, the network for some time split into two actually equal branches and there was a separation and loss (for miners) of two chains of 6 and 3 blocks, respectively. To date, almost all pools have switched to blocks of the third version, except for the two largest ones - F2Pool (formerly Discus Fish) and Antpool. Therefore, the “alarming” status on the network has not yet been canceled and blockchain bifurcations are still possible.

5. But the most interesting thing began on the evening of July 7 - someone launched an attack on the network with "transaction spam" - that is, the generation of a huge number of small transactions that completely clogged all new blocks. At the moment, it is not known who and for what purpose carries out this attack. Despite the public availability of the blockchain, the anonymity of Bitcoin makes it difficult to pinpoint the origin of these transactions. Now, about 400 connected addresses have been discovered that continuously transfer 1000 satoshis (0.00001 BTC) to each other, while paying a commission, therefore, the attack is costly for its initiator. Here is one of these addresses, and following the chain, you can find the rest.

What's happening?

Let's try to describe the current situation. Yesterday, the queue of unconfirmed transactions began to grow rapidly. Previously, it rarely exceeded 10,000, but now, according to Blockchain.info, it constantly stays above 20,000:

The total size of all unconfirmed transactions is almost 22 megabytes, which means that it takes an average of 22 full blocks to send them, but transactions keep coming in all the time. Therefore, the queue size almost does not change. The situation is aggravated by the fact that quite a lot of "empty" blocks appear in the network, containing only 1-2 transactions. Each block includes at least one transaction - in it, the miners receive the mined coins. Whether this happens for technical reasons or from the desire of pool owners to get a block faster is unknown. Each empty block pushes the queue back another 10 minutes.

The consequences of the attack are clearly visible on some charts on Blockchain.info:

You can see that both the number of transactions per block and the average block size have skyrocketed in the last two days, already dangerously approaching the maximum value of 1MB. Thus, this second stress test once again convincingly proves the need to increase the limit.

In addition to major problems, there were also smaller ones. In particular, at about 21:00 Moscow time, one of the main information resources about Bitcoin - Blockchain.info "froze" for some time.

This happened due to two blocks that the block explorer could not read - and from F2Pool, which, nevertheless, passed into the main blockchain. The service is now working, but still does not show transactions from these two blocks.

What will happen next?

The attack will obviously end soon. If the attacker is not Satoshi Nakamoto himself with his million bitcoins, the resources to continue the attack will soon be depleted, since when a queue arises, network clients automatically increase the amount of commission required for fast passage. Therefore, for an effective attack, the attacker also has to increase payments to miners.

When the attack will end, we cannot say now. But let's hope that the mysterious "tester" will declare himself and explain the motives of his actions. Perhaps this will speed up the release of a patch that increases the maximum block size - the problem is now obvious to everyone.

As for the incompatibility of block versions and the possible splitting of the chain, it is not so acute, but it may turn out to be more serious. Most of the pools have updated their wallets after warning the developers, but the two largest Chinese pools, together having up to 40% of the total capacity, have not yet been updated and it is not known when they will do so. This behavior can not only cause technical problems, which the network can deal with relatively easily, but also deal a blow to the reputation of Bitcoin. Obviously, the network self-regulation mechanisms are not very effective against large miners. You can only ignore them - by reducing security or increasing the number of confirmations.

Despite all the difficulties described above and the slowdown in the passage of many transactions, the Bitcoin network continues to work, and this is the main thing. Cryptocurrency has shown that it can withstand quite serious attacks, although many technical aspects need serious improvement.

However, it is not only free decentralized systems that suffer from technical flaws. Ironically, today, due to a technical failure, one of the largest trading floors World - New York Stock Exchange (NYSE). According to media reports, the cause was an unsuccessful update of some systems. No one in the world is immune from such troubles.

The space of Bitcoin is very large, and sometimes a lot of what happens on the network is hidden from our eyes. Luckily for cryptocurrency enthusiasts, there are many monitoring tools that monitor the statistics of the Bitcoin network and display real information. Some members of the cryptocurrency community are even trying to use these statistics to make their own predictions.

In this article, we will discuss several websites that offer statistical information about the Bitcoin network. Many of these online tools are useful for tracking and charting daily protocol changes, as well as giving us insight into the behavior of cryptocurrencies. This includes various blockchain explorers, node counters, and many other interesting analytical tools that help us look at the Bitcoin ecosystem in a new way.

Blockchain Explorers

Blockchain explorers help Bitcoin users to identify all transactions that have taken place on the network since the emergence of the cryptocurrency distributed ledger. At first, there were very few such browsers, but as the Bitcoin network grew, their number increased.

To date, the oldest blockchain explorer. Users can enter a Bitcoin address and view its content, transaction IDs, and get an overview of all transactions on the network. The site contains data on the commissions paid for the transaction, the height of the block in which the transaction is included, the number of confirmations, and much more.

In addition, the site contains a huge amount of statistical data and graphs. Users have information about the block, mining, cryptocurrency statistics and various activities on the network. The most demanded information is about the price of Bitcoin and the average block size, as well as the transaction counter and mempool size.

OXT

Another interesting blockchain explorer is a site called OXT (open exploration tool), which is a research tool for analyzing the blockchain. Similar to other blockchain explorers, OXT can display transactions on the Bitcoin network. In addition, the site analyzes various behaviors on the Bitcoin blockchain using graphs and trajectory tools. This includes time charts showing commissions, transactions, scripts and more. In addition, OXT has scatter plots in its arsenal, providing a new perspective on the behavior of Bitcoin transactions and addresses.

Other popular browsers include Blockcypher , Insight , Blocktrail and Sochain . Each browser displays blockchain data in a slightly different way, but in general, the transaction information is the same.

Network statistics graphs

statoshi.info

The Statoshi.info website provides real-time statistics of the Bitcoin network. The site's dashboards include host counters, bandwidth usage, transaction fee estimates, system performance metrics, memory pool information, and more. The site has been around for several years, with each dashboard displaying various graphs that analyze certain sections of network and protocol behavior.

Another graphic site that has been around for quite some time. The price charts presented on the site are very popular among network users. BitcoinWisdom price charts reflect the value of the cryptocurrency on various exchanges such as Bitstamp, BTCC, Kraken and Bitfinex.

BitcoinWisdom also shows other statistics, such as network difficulty or past and current hashrate.

Another site containing statistics on the Bitcoin network is called . Users are offered a variety of charts that display past and current statistical information about Bitcoin. The site interface contains a counter of mempools, mined blocks, transactions and many other useful network diagrams. Tradeblock also monitors the Ethereum blockchain and has its own browsers.

“Tracking Bitcoin” is also possible using the site. This tool demonstrates the visual interpretation of network transactions, as well as the association of transactions with individual addresses. The site traces the origin of Bitcoin and follows its path through the blockchain using visual diagrams.

Host information

Node Counter

Node Counter is an analytical website that monitors the nodes of the Bitcoin network. Here are graphic representations of Bitcoin Core, Classic and Unlimited (BU) nodes. Each table shows different nodes on the network, as well as pools that have reported support for alternative Bitcoin clients and block size proposals. Information on Nodecounter is presented in the form of line graphs and pie charts.

Founded by startup 21 Inc, the site is also often used to explore various graphs and tables that depict the behavior of the nodes of the Bitcoin network. The site provides a snapshot of the network, as well as a search tool for checking the status of nodes. Bitnodes displays nodes by Bitcoin Core, Classic, and Unlimited (BU) clients.

Coin Dance

Another very useful tool bears the name. It shows users various analyzes and graphs related to the nodes in the network. The graphical interface also contains implementations of different nodes with different types of graphs. CoinDance is also popular due to other data presented, such as trading volume on Localbitcoins and Paxful, or even charts reflecting the opinions of well-known companies in the industry regarding the support of Segregated Witness, Emergent Consensus and UASF (BIP 148).

Visualization Gives a New Perspective on the Bitcoin Network

All these monitoring sites offer us a different view of the network, and each of them, depending on the goal, has its own merits. The information provided through these tools can improve our relationship with the network by providing a better understanding of what is happening. In some cases, the graphical display is best method interpretation of network operation and protocol behavior.

Bitcoin transaction is the transmission of data to common network and display them in blocks. A block includes not one, but many transactions that are awaiting confirmation.

What are transactions in the Bitcoin network?

Information about operations with bitcoins is recorded in special blocks, which are a list of transactions. If you put the blocks in a chain, you will get the history of the “walking” of the cryptocurrency.

The block consists of a header and a list of transactions. The header contains the hash codes of transactions, own and the hash of the previous block . The first in the list is a transaction that indicates the reward (commission) for creating a new block.

To verify the authenticity of cryptocurrency transactions, transactions must be validated on the blockchain. It is a distributed database. Its parts are stored on many computers in the Bitcoin network.

Confirmation of a transaction is its attachment to the list of transactions in the block.

After a transaction with a cryptocurrency, the accounts on the side of the sender and the recipient are not updated immediately. In traditional user applications, to confirm a transaction, six blocks must be found that prove its validity.

In this case, the user conducting the operation can reduce the number of checks. This should be done if you operate with a small amount of bitcoins. This simplifies and speeds up the transaction confirmation process.

If the verification of the transfer of crypto money did not occur, the system returns the funds back to the sender's wallet.

What is 3 confirmations in the Bitcoin system?

How to get confirmation?

To reduce the possibility of double use of funds, any transaction must receive a certain number of confirmations (a requirement of the Bitcoin system). Various online services set their own confirmation threshold.

To receive confirmations, the owner of the wallet does not need to do anything. The Bitcoin system automatically generates confirmations over time.. This process takes from 5 to 30 minutes, in rare cases several hours.

Transaction time in the Bitcoin blockchain

On average, a transaction takes from 20 minutes to 60 minutes, but at peak times this time can be increased many times over.

To make a transfer, the transaction must be verified in 6 blocks . If this does not happen, crypto money will not reach the final destination. Accordingly, the time of sending finances depends on the speed of confirmations.

The blockchain.info website is unstable, and the queue for transfers continues to grow steadily. At this speed, even without adding new transactions, it will take more than 8-10 hours to process the existing queue: https://blockchain.info/ru/unconfirmed-transactions

The waiting time depends on the workload of the blockchain network. Over the past two years, the number of bitcoin transactions has increased by more than 8 times.

In general, bitcoin holders should expect a period of 2-3 hours to 2 days.

Transfer processing time may increase in the following cases:

1. Excessive network congestion during sharp fluctuations in the bitcoin exchange rate;
2. Low transaction priority (frequent transfers of small amounts);
3. Low commission.

This can be seen in the chart below:

It shows the growth in the number of trillions of hashes executed per second on the Bitcoin network.. There are also bursts in the network when the average number of transactions in blocks increases, and the block size itself increases to a critical value.

Transaction time reduction methods:

1. Increasing the commission for miners- experts advise “not to be greedy” and give back 0.0002 BTC or more for confirmation.
2. The amount of funds transferred– the more cryptocurrencies you transfer, the higher the status of the operation in the “crypto network”.
3. Use of specialized sites like coinbase.com - on such services, buyers and sellers save their keys. Thanks to this, confirmation takes place within this platform, and not in the general network.

How to verify a bitcoin transaction?

You can track your bitcoin transaction using public services (registration is not required):

To find out how many network confirmations have passed for a particular transaction, go to the Blockchain.info or Chain.so site and enter in search string the transaction hash you know. After that, all information about the block and its current status will be displayed.

Currently 2 confirmations

Confirmed and unconfirmed transactions

The process of including a transaction in the found block is called transaction confirmation. Inclusion in 1 block = 1 confirmation, when there are 6 such confirmations and above, the transaction is considered confirmed. This feature was introduced to protect against repeated spending of the same bitcoins.

The classic Bitcoin client will display the transaction as "unconfirmed" until there are 6 confirmations (6 blocks found). Sites or services that accept Bitcoin to pay for their goods or services may set their own limits on the number of blocks needed to confirm a transaction.

The number 6 was not chosen by chance: it is based on the theory that the likelihood that an attacker can accumulate more than 10% of the network hashrate to fake transactions is small, and that a negligible risk (less than 0.1%) is acceptable.

If the transfer is not completed within 20-30 minutes, do not panic. With heavy network traffic in recent days, even high-fee transactions may take longer to process than usual. Also, do not worry about the safety of your funds - if the transaction is not included in the block, the bitcoins will return to your wallet after a timeout (usually 72 hours).

Do you want to at least roughly know how much longer the translation will be carried out? To do this, you need to know the transaction hash. If you remember the commission that was set during the transfer, immediately go to step 4.

• First you need to know the amount of the commission for the transaction. This can be done on one of the public services. We go to blockchain.info, enter the hash in the search field, and click on the transaction.

Opening the translation details

• We look at the column "Pay per byte" - this will be the value we need.

High commission is the key to a fast transaction

Find out the confirmation time - btc.com

In addition, on these sites you can find out the recommended commission value - this will come in handy for future transfers.

1. Remember:

the size of the commission does not depend on the amount, but on the size of the transaction in bytes

1. So, in the figure above, when transferring 3.3 BTC, the fee per byte is 372 satoshi, and the transaction size is 191 bytes. Therefore, the total transfer fee in this case is 372 x 191 = 71,052 satoshi, or about $11 (at a bitcoin rate of $15,500 for 1 BTC).

How to speed up a bitcoin transaction?

Let's consider several ways how to use the blockchain system in "high-speed mode":

1. Using centralized services with a separate transaction system . There are resources that offer services to create and use Bitcoin wallets that conduct digital currency transactions between their clients without involving the blockchain ecosystem. Such services offer their clients instant transactions, but only if the currency transfer occurs within the system. One such service is Coinbase.. It has a transaction system separate from the blockchain, thanks to which transfers can be made almost instantly.
2. Using multi-signature to speed up transaction confirmation in the Bitcoin system. Some companies, such as GreenAddress, in addition to the standard transaction signature provided by the system, put their multi-signature as confirmation of the reliability of the transfer. The blockchain system considers such transactions as reliable and they are faster accepted into the generated block. In addition, the use of multi-signature technology increases the security of cryptocurrency transactions.
3. Using open transactions and trusted servers . The bottom line is that an open transaction, when all information about the sending and receiving parties is present, receives confirmation of the system faster by accepting data into the generated block. But few people use open Bitcoin transactions, as this contradicts the very idea of ​​​​using a digital currency, namely, the anonymity of money transfers.

Speed ​​up transactions with Opt-In Replace-by-fee

The easiest way to force your transaction to jump the queue is to use an option called Opt-InReplace-by-Fee (Opt-InRBF). With its help, you can resend the same transaction, but with a higher commission.

Without this feature, when a transaction is resubmitted on the network with an increased fee, the network will reject the new transaction. Bitcoin nodes usually treat a new transaction as a double spend and therefore do not accept or delay it.

However, by sending a transaction using Opt-InRBF, you are essentially telling the network that you can resend that transaction at a later time, but with a higher fee. As a result, most Bitcoin nodes accept the new transaction instead of the old one; thus, the new transaction jumps the queue.

Whether your transaction will be included in the next block depends on which miner will mine a new block: not all miners use Opt-InRBF. One way or another, enough miners support this option so that your transaction is included in the next few blocks.

Currently, the Opt-InRBF feature is supported by at least two wallets: Electrum and GreenAddress. In Bitcoin Core, it is supported when processing transactions, however, creating your own RBF transactions is possible only with the help of third-party scripts. Depending on the wallet, it may be necessary to update the Opt-InRBF in the menu settings before sending the (first) transaction.

Bitcoin transaction fees

The peculiarity of the Bitcoin system is the fact that the user can set the amount of the commission at his own discretion . But the duration of the translation directly depends on this value. The larger its amount, the higher the priority level of the corresponding operation and the less time it takes to receive confirmation from the system.

In the Bitcoin blockchain, transactions with a large reward to Bitcoin network miners are the first to be validated. In some cases, if you save a lot, the confirmation procedure may take several days.

What commission to set so that the transaction does not freeze - table!

The size of the commission does not depend on the amount of the transaction, but depends only on the size of the transaction in Bytes. A transaction is essentially a kind of script that occupies a certain place in Bytes, and it is more difficult for miners to process it, the larger it is.

Below is a table of priorities for including a transaction in a block. The recommended commission is predicted taking into account the load of the Bitcoin network in order to quickly confirm your transaction.

Last column in the table shows the prediction that a payment with a transaction fee corresponding to this line will fall within the confirmation time interval from 0 to 25 minutes.