## hashpower – I need good mining SW for Linux where I can inject a hashing accelerator library. Recommendations?

I have access to a powerful accelerator for a number of hashing algorithms.

I’d like to get hold of mining SW for Linux that has the following features:

• CPU mining
• Offline benchmarking

My plan is to intercept calls to SW implementations of SHA-256 & resolve them in the accelerator.
I would then like to obtain a hashrate for the accelerated version.

Do you have any recommendations for good, reliable projects that can be useful for this purpose?

## Reversing network hashpower – Bitcoin Stack Exchange

I’m reading this article by Vitalik Buterin on Problems in Cryptocurrency and don’t quite understand what this means:

Ideally, after some number of blocks (perhaps logarithmic in the total size of the network) every transaction should require 51% of network hashpower to reverse. However, solutions where transactions can pay very small fees for a lower “level” of security are acceptable, though one should take care to avoid situations where an attacker can profit by performing one attack to reverse very many small transactions at the same time

I understand that Sybil attack can happen if more than 51% of the network is under one person’s control, but I don’t understand what it means to reverse network hashpower, and why 51% of it should be reversed.

## Hashpower: what is the algorithm to create a Bitcoin mining calculator?

I want to give an extended answer since I found the preexisting here or elsewhere that needs a little more clarification, specifically for newcomers.

## Formula

To calculate the approximate total value of bitcoin earnings per month from a mining operation (regardless of mining costs (electricity, hardware maintenance, etc.)), the following formula can be used:

``````H = Hashrate (hashes / second)
D = Difficulty (Reference for values below)
B = Reward per Block (Reference for value below)
N = Number of days per month (default = 30)
S = Number of seconds per day (S = 60 * 60 * 24 = 86400)
``````

## Example

``````H = 21,990,232,555,520 h/s (~= 20TH/s)
D = 47,427,554,950.648
B = 25
N = 30
S = 86400
``````

The total number of bitcoins won per month according to the variables defined above will be ~ 6,995. Discard `N` of the numerator and you will get the daily value.

## Piton

A quick Python declaration as an implementation example (you can write this directly to the terminal)

``````\$ python -c "print (30*21990232555520*25*86400)/(47427554950.648*2**32)"
\$ 6.99542703277
``````

## Some references:

Difficulty (Current value | Wiki)

Block reward (Current and future values)

## Hashpower: Bitcoin hash rate drop: can 51% attack work?

The bitcoin hashrate flash crashed 40% yesterday (September 23, 2019). The hash rate has been in a continuing upward trend since May 2019 and, miraculously, the hash rate has fallen by a huge 40%.

Can it be a proverbial canary in the coal mine that a mining group or a single establishment has diverted its hash power to build blocks on the side for a 51% attack on the network?

If such an attack took place, for example, how can full nodes guarantee network protection?

## hashpower: determination of the geographical distribution of hashrate

I would like to map the hashrate distribution geographically, which would require knowing the winning miner's IP address for each block.
According to the article by Miller et al. See: https://www.cs.umd.edu/projects/coinscope/coinscope.pdf
Several aggregator websites, including blockchain.info, maintain low-latency connections to thousands of nodes and register the IP address of the first node connected to relay each block. Is this information provided somewhere? While blockchain.info provides a hashrate distribution, it is added at the group level, while I would like to know more about how the hashrate is distributed among the groups' servers.

## Hashpower: what are the chances that large bitcoin mining groups will join and attack 51%?

Looking at this bitcoin hash rate distribution chart (https://www.blockchain.com/en/pools), only 3 to 4 mining groups are needed to join and perform a 51% attack.

With this possibility, how can people continue to think that Bitcoin can be the money of the future?

PD: I am also a bitcoin believer

## hashpower – How is the pool's hashrate quota known?

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## hashpower – Can the reduction be halved by Bitcoin?

Currently, the next halving date is May 2020 (provisional) according to the description of the link here.

I understand that every 210k blocks, the block reward is cut in half and this works, approximately, once every 4 years.

I guess I have two questions:
1) The reduction in the middle of 2012 took place approx. 3.8 years after the genesis, and the reduction in the middle of 2016 took place another 3.6 years after that. During this period, the hash rate increased almost continuously and at exaggerated rates due to continuous developments in mining technology, from general to specific solutions (CPU -> GPU / FPGA -> ASIC). So, were these reductions & # 39; premature & # 39; due to the positive change rate of the hash rate?

2) A reduction by half on May 23, 2020 is approximately 3.9 years since the last reduction in half. It seems that this is linked to the fall of 2018 in the hash rate, Could a collapse of the hash rate lead to a halving event (ie, adding the current 210,000 blocks takes more than 4 years)?

Thank you.

## hashpower: hash rate of average PC / upper end PC

Hi, I was wondering if anyone had any idea about how the hash rates are with recently released PCs. I'm looking for figures to use for an average user if they wanted to use their PC for mine, and then a kind of better case, for the hash rate of someone who has a good graphics card, etc. Any sources or information from personal experiences would be great, thank you!

## hashpower: What prevents the miners from sending failed hashes to the network to reduce the difficulty and block the time?

Miners not to do Spread failed hashes to the network. They do not do anything with them, they simply ignore them and try again. Nobody else sees them.

The way we know that the hash rate of the network is not observing all the hashes that were made. Rather, when we see a successful hash, the difficulty of the network allows us to infer the number of non-successful hashes that, on average, must have been made to obtain it.

For example, the difficulty of the network is currently 6.07e12. This means, approximately, that a successful hash is required to start with approximately 74 zero bits, so the probability that a given hash is successful is approximately 2.6e22. Therefore, each time a single successful hash is transmitted to the network, we infer that around 2.6e22 hashes must have been made throughout the network. Since the success is random, the actual number of hashes executed from the previous successful hash may have been significantly more or less. But when we average many blocks, we can arrive at a reasonable estimate of the overall rate at which the network is doing hashes, even if we only see the successful ones.

Similarly, adjustments to the difficulty of the network are not directly based on the overall hash rate. Rather, they are simply based on the speed at which successful Hashes have been observed; Specifically, how long has the last 2016 taken. successful hashes to appear. From the previous discussion, this is correlated to the global hash rate, but the global hash rate is not really used in the calculation of difficulty adjustment.

In her example, Alice's decision to transmit failed hashes or play no role in the Bitcoin protocol. If it transmits a failed hash (that is, a block with an incorrect work test), it will simply be ignored. In fact, it is likely that other nodes in the peer-to-peer Bitcoin network will be disconnected from it (the so-called "prohibition"), because it is saturating the network with useless garbage.