How do bitcoin miners iterate: tracking S9 and S17 miners through nonce maps

Source: babbitt

Original title: "the dynastic succession of bitcoin miners: tracking S9 and S17 miners through nonce maps"

As bitcoin's next output halves, the network is going through several transitions. In addition to major changes in the mining economy as a result of the incentive adjustments, bitcontinental's Antminer S17 is replacing the long-existing S9 series of miners and becoming network-driven mining hardware.

The bit-continental Antminer S9 was released in 2016 and has since quickly become the most popular sha-256 miner on the market, and after several years of development, the S9 still accounts for a large portion of the market.

The lack of public data on the types of mining hardware used by individual miners makes it difficult to measure how quickly the transition is taking place. However, one source does reveal a trend in mining hardware: the network's nonce random number distribution. The way these arbitrary Numbers are arranged (miners include them in the hash of each block) hints at how the use of mining hardware has changed over the years.

In our last report on the state of the network, we looked at how to use the random number distribution pattern to detect the rise of asics. In this report, we will further explore the particularity of the random number distribution of bitcoin nonce and the source behind the distribution stripe to investigate the latest changes in mining hardware. We then break down the data by pool to get a deeper understanding of the hardware used by a particular pool.

Learn about bitcoin mining through gold marbles

Mining is a key part of bitcoin's security model and arguably the most important improvement on previous attempts to create digital currencies. While the implications of mining are complex, the concept behind it is relatively easy to understand.

From the miner's point of view, digging a block is similar to repeatedly selecting marbles from a bag without replacing them. Remember, the number of marbles in the bag is very large, the proportion of blue marbles is very large, and the proportion of gold marbles is very small. When the miners remove the gold marbles from their bags, they receive a reward.

In more technical terms, what bitcoin miners are scrambling to find is a golden random number that, when added to the proposed block head, is hashed below a specific value determined by the network difficulty parameter. The miner searches for the one-time nonce or arbitrary number by guessing the value and checking whether the result hash is below a certain threshold. The first miner to find the value for the valid block and broadcast it to the network has the right to select and sort the transactions in the block, which is a necessary step to ultimately make these transactions valid.

In return, miners receive a block reward and a processing fee from any deal included in the block, both through a special coinbase deal. Assuming that the properties of the sha-256 hash function remain unchanged, the distribution of the golden nonce for any given block is random, and unless calculated by brute force, the golden random number cannot be found.

Since the reference to the coinbase transaction is contained in the block header, each mining entity is sampled from a different distribution. In other words, each entity takes marbles from a different bag, and the bag contains the same number of marbles, and the ratio of blue and gold marbles is expected to be the same.

The proportion of golden marbles is determined by the network difficulty parameter (which is automatically adjusted by the network) and fixed within the relevant period. Nowadays, due to the high block difficulty and random variance, there is usually no golden nonce random number for a particular block head. In other words, some bags have no gold marbles in them.

Miners who run out of random number space in the proposed block typically increase the timestamp of the block to generate a new set of random Numbers. In other words, when the miners finished collecting the marbles, they would grab a new bag full of marbles. If the timestamp has reached the point where it is invalidated by further adjustment, the miner must adjust the set of transactions contained in the block. Similarly, if a miner runs out of bags in the room, they need to grab more from the other room, which is time intensive.

To increase the probability of finding a golden marble in a fixed time, the miners could parallelize their calculations, which are similar to grabbing a handful of marbles at a time, rather than one at a time. By using hardware suitable for the task (particularly the GPU and dedicated chips called asics), you can look up nonce random Numbers in parallel. And the parallelization efficiency of ASIC is higher than any other method.

In another form of parallelization, several miners coordinate their nonce findings and agree to split any mining returns. Groups of miners who do this are called pools, and their operators typically charge a fee that individual miners accept to reduce the volatility of their earnings.

Bitcoin's Nonce random number distribution

The bitcoin difficulty parameter is adjusted every two weeks, so that if the amount of computation performed on the network remains constant, a new block is generated every 10 minutes on average. This feature ensures that the network will continue to function even if the computational power may change significantly. In a fully competitive mining market dominated by parallel computing miners, we can expect the distribution of golden nonce random Numbers to look evenly distributed over time. Surprisingly, this is not the case.

The non-random distribution near the left of the figure can be attributed to mining through an iterative test value from 0. If a miner is working through a CPU and as an individual without parallel mining, and therefore cannot conflict with other members of the pool, this strategy is as effective as any other, because the nonce distribution of each new block is independent. The disappearance of this pattern coincided with the introduction of GPU miners, who enabled parallelization of computing.

Near the right of the figure, there is a striated area with few nonce random Numbers. To our knowledge, this anomaly was first discovered by Twitter user @100trillionusd in January 2019. The area is marked below.

Shortly thereafter, BitMEX's research paper explored this strange pattern, speculating that the anomaly was due to the controversial mining optimization technique AsicBoost.

There are two variants of AsicBoost: 1. Implicit AsicBoost (which cannot be reliably observed on the chain), and 2. Public AsicBoost (which can be explicitly observed on the chain). The BitMEX research team discussed the two variants, but was particularly interested in the effects of the hidden AsicBoost, which was almost impossible to use in non-empty blocks with the activation of the SegWit in August 2017. Of course, the researchers could not confirm their suspicions.

In our October 2019 issue 23 report, we delve into bitcoin's nonce random number distribution and point to the stripe pattern. Since then, the stripe pattern has gradually disappeared, and the random Numbers in the recently mined blocks seem to be distributed more randomly.

Exceptions in the random number distribution, however, do not appear to be directly related to AsicBoost. Hidden AsicBoost became unavailable in 2017, and the first firmware update to support public AsicBoost was released in October 2018, but the nonce distribution streak between the two dates is clearly visible. In addition, while public AsicBoost usage is still high, this abnormal pattern is no longer visible in newly produced blocks, whether or not there is an obvious AsicBoost.

Another possibility is that the pattern in the distribution of nonce random Numbers may have been caused by the way the Antminer S7 and S9 families in bitcontinental sampled nonce random Numbers. This image may be caused by a side effect of the optimization and is ultimately harmless to both the miner and the network.

When looking at all the random nonce values on the network, the stripe pattern first became clear in late 2015, which was consistent with the time when bitland released the S7 in late August and completed the order in late September.

Antminer S9 was released in late May 2016, and the first buyers received orders in mid-june of that year. Soon after, as the S9 replaced the S7 as the dominant miner of the bitcoin network, the stripes became narrower and narrower.

The recent collapse of this pattern coincided with the transition from S9 to Antminer S17, the main miner on the network. Although the S17 was released in April 2019, miners were using the S9 until recently because of the economics of mining.

meta-analysis

By layering the miners' data sets for each block, we can look at the nonce distribution more fine-grained.

As we know, the miners in the block are usually identified by the tags in the coinbase data field of the block, and these signs are provided voluntarily, there may be a case of forgery, the miners do not need to leave information, they can choose to leave another mine pool tag to replace their own. Therefore, in some cases, these misleading behaviors even exist incentives, so we should recognize the shortcomings of this approach. However, the technology is now the industry standard, and while many miners choose not to leave an identification number, we do not believe that large-scale counterfeiting is taking place.

Once we've sorted the blocks by miners, we can incorporate this information into our distribution of bitcoin nonce random Numbers.

We can also look at the distribution of nonce random Numbers for individual pools. Even in this case, the exception pattern is still visible. See the chart below, which shows the blocks mined by Antpool and BTC.com (both owned by bitcontinental) and ViaBTC.

In the nonce distribution of the affiliated ore pools in bitu continent, the fringe pattern is more distinct. This suggests a high proportion of S7 and S9 miners were in the pools during the relevant period, which was in line with expectations given the association between the pools and the manufacturers of these miners.

The proportion of blocks mined by unknown entities fell sharply in 2015, a result of the block-expansion war, during which many previously anonymous miners began identifying themselves on the chain to show support or opposition to the increase in block size. Today, the vast majority of miners can be identified by hashing. The striations are dimly visible in nonce random Numbers in blocks mined by unknown miners, as are their gradual disappearance.

conclusion

The Antminer S9 has been the most used mine on the bitcoin network since its release in 2016. Despite the release of the S17 by bitcontinental last year, the S9 remained economically viable for some time, but the model is being phased out due to the growing power of the network and changing market conditions.

As the miners made the transition from S9 to S17, the striped pattern that used to define the distribution of bitcoin's random Numbers disappeared. The origin of these mysterious streaks, which appear in a seemingly random space, has long been the subject of speculation. The timing of the stripe's visibility supports the theory that the lines are the product of mining hardware, particularly the previous S9 and S7.

Nonce data allow us to measure the scale and speed of this transformation in a way that would otherwise be impossible, using only public information. We can estimate the proportion of these miners on the network by using the traces left by S9 in the nonce sample. The separation of these data by pool provides unique information about the miners' efficiency, which we will cover in a future report.

原文链接： http://www.wabi.com/news/26455.html

Welcome to join the official BlockBeats community:

Telegram Subscription Group: https://t.me/theblockbeats

Telegram Discussion Group: https://t.me/BlockBeats_App

Official Twitter Account: https://twitter.com/BlockBeatsAsia