BFGMiner is a modular ASIC/FPGA miner written in C, featuring dynamic clocking, monitoring, and remote interface capabilities.Where can I have more information about BFGMiner?Please refer to the official forum thread on BitcoinTalk.NEW VERSION 5.4.2, MARCH 26 2016 You can read the full changelog here.Bitcoin, one of the world's newest currencies, is an open source, peer-to-peer currency that does not exist in physical form.It's owned and traded by means of an anonymous P2P network, without any third-party intermediary like a payment processor, without any government issuing or tracking the virtual currency.While there is a limit of only 21 million bitcoins to be generated by the year 2140, bitcoin is "free" to generate and is created by "bitcoin miners."Ihaven't played around with bitcoin, but Launch called bitcoin peer-to-peer currency "the most dangerous project we've ever seen," suggesting it could "topple governments, destabilize economies and create uncontrollable global bazaars for contraband."

According to Big Think, bitcoin will be a bank for Anonymous."The hacktivists now have a virtual currency that's untraceable, unhackable, and completely Anonymous."WiredUK tried to explain how bitcoin miners dedicate their CPU/GPU to generate the virtual currency."It's generated by Bitcoin 'miners' over time by using CPUs and GPUs to solve a cryptographic problem -- hashing some data against a function.If your computer manages to generate a hash that's numerically lower than a defined value, then you shout it out to the rest of the network, and get to pocket the newly-minted Bitcoins, while also signing a series of transactions and making sure they're legitimate."One of the issues, other than if governments will try to outlaw bitcoin, is the high amount of electricity needed to create a single bitcoin.It might cost more to generate a bitcoin than the actual value a bitcoin is currently traded at.High electricity bills can lead to marijuana busts.And it is this unusual power consumption needed that caught my attention since it appears as a bitcoin miner has been mistaken as a person running a marijuana growing operation.Blogger Mike Esspe captured an IRC chat that supports the rumor floating around that at least one bitcoin miner has been arrested.

In regards to if being a miner will bring the cops to your doorstep, according to the Bitcoin Miner, the power consumption will be somewhat like the electric usage for "marijuana grow-op."litecoin how to get startedAn example was "The Canadian town of Mission, BC has a bylaw that allows the town's Public Safety Inspection Team to search people's homes for grow ops if they are using more than 93 kWh of electricity per day."buy litecoin visaThere have allegedly been reports floating in IRC of two different cases of police showing up at a bitcoin miner's residence with a search warrant.bitcoin plugin minecraftWill it become more common to confuse bitcoin miners with weed-growing operations?berita bitcoin indonesia

It is somewhat common for police to monitor unusually high power consumption if a person is a "suspect."For example, as NetworkWorld noted, Ohio police and the DEA file at least 60 subpoenas each month for energy-use records of people suspected of running an indoor pot growing operation.bitcoin kurs 2014If a stakeout does not uncover anything illegal or point to a "grow house," then utility consumption records can be sought.bitcoin per klickDEA Agent Anthony Marotta said high electricity usage does not always mean the residence is an indoor pot farm and has surprised federal agents."We thought it was a major grow operation ... but this guy had some kind of business involving computers.I don't know how many computer servers we found in his home."Itis unclear at this point if more bitcoin miners will have police show up with a warrant on their doorstep after more false positives, mistaking the power consumption to create virtual P2P currency as electricity usage needed to grow weed.

If you're seeing this message, it means we're having trouble loading external resources on our website.How One Art Festival Encourages And Celebrates Global DiversitySnapchat Unveils A New Way For You To Stalk Your Friends--And Other Stories You Might've MissedThis Company Delivers Wine In Bottles, Cans--And Soon, Kegs?Grindr For Equality Is Turning The Gay Hookup App Into A Trusted Source Of Health And Wellness InfoTravis Kalanick Is Out--Where Does Uber Go From Here?General Stanley McChrystal’s Remedy For A Divided NationWhy Webcams And The Internet Are Tools For ArtHow The VP of Global Marketing At Facebook Got Her Start Serving Sandwiches At A TheaterHappy 30th Birthday To The GIF!Seattle's Space Needle Is Getting A Major Facelift--And Other Stories You Might've MissedHow Previously Working For An Oil Company Helped Shape This Jigsaw Employee’s ValuesEver Wanted To Eat Your Beer?Well Now You CanFrom Film FX To The U.S.Department of Defense: Inside Zoic’s Revolutionary LabThis is the official documentation of lightweight bitcoin mining protocol.

If you’re looking for Bitsolive mining proxy, please visit mining proxy howto.If you’re looking for mining software compatibility, please go to the compatibility section.This page is both a technical documentation and advocacy of the new mining protocol which can be used for bitcoin mining.If you're a casual miner or just a regular bitcoin user, then you don't have to understand everything in this document.The main reason why I designed this protocol and implemented opensource pool server is that the current getwork&LP mining protocol has many flaws and it can hardly be used in any large-scale setup.ASIC miners are probably coming at the end of the year 2012, so Bitcoin community definitely needs some solution, which will easily scale to tera-hashes per second per pool user... 1.Why to Change Something That Works?HTTP: Communication is Driven by Miners... ... However pool server knows much better when clients need new mining jobs.HTTP was designed for web site browsing where clients ask servers for specific content.

Pooled mining is different - server knows very well what clients need and can control the communication in a more efficient way.Let’s swap roles and leave orchestration to the server!Ntime Rolling: Not Enough Jobs For Fast Miners Nowadays, for every received job from the server, a miner can modify only ntime and nonce.Nonce is a 32bit integer (4.2 billion of iterations).Ntime is a 32bit integer storing UNIX timestamp and should reflect current time, although optimized miners roll ntime slightly into the future, which gives more combinations to miners (nonce range * ntime range).However, a block created from massively modified ntime can be rejected by Bitcoin network.Strictly following getwork specification, one getwork job is enough for 4.2GHash/s mining rig and (thanks to ntime rolling) this job is usable for one minute or until a new Bitcoin block arrives (depending on what happens first).So, for 42 GHash/s rig you’ll need 10 getwork requests at once, but usually a few more because of some pre-caching strategies implemented by miners to prevent idling on network latencies.

And what about 1 THash/s ASIC miners coming soon?We simply need some solution where network load is not at all bounded to miners performance.Long Polling: An Anti-Pattern Getwork came as an easy solution for building standalone miners (do you remember when the official Bitcoin client was the only miner?), much before I built my first Bitcoin pool and when frequent polling of local bitcoin daemon wasn't an issue.When pools came into the game, people found out that they must decide between short polling intervals (=higher network load, lower stale ratio) and intervals, which don't overload network and servers, but lead to a much higher ratio of rejected shares.And long polling pattern was the answer.Long polling is a great way to achieve real-time updates using standard web technologies.But as I already mentioned in the text above, web technologies are not ideal for Bitcoin mining.Long polling uses separate connection to pool server, which leads to various issues on server side, like load balancing of connections between more backends.

Load balancing using IP hashes or sticky HTTP sessions are just another workarounds for keeping all that stuff working.Another problem consists of packet storms, coming from clients trying to reconnect to the server after long polling broadcasts.Sometimes it's hard to distinguish valid long polling reconnections from DDoS attacks.All this makes pool architecture more complicated and harder to maintain, which is reflected in less reliable pool service and has a real impact on miners.The solution for such issues is related to the previous point about driving load by the server and not by thousands of (sometimes) strangely implemented miners, who are aggressively trying to reach the server.How Can We Fix All That?Now we know what's wrong in the current situation, so let's design a new protocol and don't repeat bad decisions again: Bitsolive Protocol I originally designed Bitsolive protocol for lightweight Bitcoin client called Electrum.Later I found out that protocol requirements are quite similar to requirements for bitcoin mining, so I decided to reuse it as-is.

Don't be confused by an esoteric protocol name, I tried to stick to standards as much as possible.In a simplified manner, Bitsolive is a line-based protocol using plain TCP socket, with payload encoded as JSON-RPC messages.Client simply opens TCP socket and writes requests to the server in the form of JSON messages finished by the newline character .Every line received by the client is again a valid JSON-RPC fragment containing the response.There are good reasons for such solution: it is very easy to implement and very easy to debug, because both sides are talking in human-readable format.The protocol is unlike many other solutions easily extensible without messing up the backwards compatibility.As a bonus, JSON is widely supported on all platforms and current miners already have JSON libraries included.So packing and unpacking of the message is really simple and convenient.There's no HTTP overhead involved and there're no hacks like mining extension flags encoded in HTTP headers anymore.

But the biggest improvement from HTTP-based getwork is the fact, that server can drive the load by itself, it can send broadcast messages to miners at any time without any long-polling workarounds, load balancing issues and packet storms.Extra nonce Rolling: The New Dimension This is probably the most innovative part of the new protocol.In contrary to current mining where only ntime and nonce can be iterated, Bitsolive mining protocol gives a power to miners to easily build unique bitsolive transactions locally, so they'll be able to produce unique block headers locally.I recommend to iterate four bytes of extranonce, which gives the possibility to serve 18 EHash/s (Exa-hashes/s) mining rig from a single TCP connection.But it can be easily changed by the pool operator anytime.Now it is going to be a bit technical, so let's explain it a bit.Block header (that string what is in getwork response and what miners are hashing) is composed from following parts: To produce more unique block headers (and thus be able to generate more unique hashes), we have to modify something.

Every bitcoin block contains so-called bitsolive transaction which specify the bitcoin address for sending block reward.Fortunately there's a chance to modify this transaction without breaking anything.By changing bitsolive transaction, merkle root will change and we will have unique block header to hash.Currently this (creating unique bitsolive) happens on pool servers.So let's move it to miners!I considered many solutions for serializing and deserializing message payloads.I wrote some reasons for JSON above, but let's sumarize them again: Why I throw away other serializers: Getblocktemplate introduced in bitcoind 0.7 is a very progressive solution for delegating block creation from full bitcoin client to standalone, specialized software.Bitsolive mining server uses getblocktemplate mechanism under the hood.There are still some reasons why Bitsolive is, in my opinion, a better solution for pooled mining: There's really only one reason why Bitsolive is worse than getblocktemplate solution at this time: miners cannot choose Bitcoin transactions on their own.

In my experience 99% of real miners don’t care about transaction selection anyway, they just want the highest possible block reward.At this point they share the same interest with pool operator, so there’s no real reason to complicate mining protocol just for those 1% who want to create custom blocks for the pool.I already have some ideas for Bitsolive mining protocol extension, where miners will be able to suggest their own merkle branch (I call it internally “democratic mining”), which will solve such issues as centralized selection of transactions.For now I decided to focus on such a solution, which will fit to majority of miners and do some extensions later.For Mining Software Developers Bitsolive protocol is based on JSON-RPC 2.0.In this chapter I expect that you're familiar with this protocol and you understand terms like "request", "response" and "notification".Please read JSON-RPC specification for more details.For high level image of the Bitsolive protocol concept, please read Bitsolive protocol specification on Google docs.

This document needs some care, but give you the basic examples how to connect to Bitsolive server.Bitsolive defines simple exception handling.Example of rejected share looks like: {"id": 10, "result": null, "error": (21, "Job not found", null)} Where error field is defined as (error_code, human_readable_message, traceback).Traceback may contain additional information for debugging errors.Proposed error codes for mining service are: This chapter contains real log of miner-pool communication which solved testnet3 block 000000002076870fe65a2b6eeed84fa892c0db924f1482243a6247d931dcab32 On the beginning of the session, client subscribes current connection for receiving mining jobs: {"id": 1, "method": "mining.subscribe", "params": []} {"id": 1, "result": [ [ ["mining.set_difficulty", "b4b6693b72a50c7116db18d6497cac52"], ["mining.notify", "ae6812eb4cd7735a302a8a9dd95cf71f"]], "08000002", 4], "error": null} Reminder: The newline character is a part of the message and must be added to the end of *every* JSON message.

Server may wait to this magic character to start processing the message.This is the most common mistake which people implementing line-based clients do!The result contains three items: Now let authorize some workers.You can authorize as many workers as you wish and at any time during the session.In this way, you can handle big basement of independent mining rigs just by one Bitsolive connection.{"params": ["slush.miner1", "password"], "id": 2, "method": "mining.authorize"} {"error": null, "id": 2, "result": true} Server Start Sending Notifications With Mining Jobs Server sends one job *almost* instantly after the subscription.Small engineering note: There's a good reason why first job is not included directly in subscription response - miner will need to handle one response type in two different way; firstly as a subscription response and then as a standalone notification.Hook job processing just to JSON-RPC notification sounds a bit better to me.{"params": ["bf", "4d16b6f85af6e2198f44ae2a6de67f78487ae5611b77c6c0440b921e00000000", "01000000010000000000000000000000000000000000000000000000000000000000000000ffffffff20020862062f503253482f04b8864e5008", "072f736c7573682f000000000100f2052a010000001976a914d23fcdf86f7e756a64a7a9688ef9903327048ed988ac00000000", [], "00000002", "1c2ac4af", "504e86b9", false], "id": null, "method": "mining.notify"} Now we finally have some interesting stuff here!

I'll descibe every field of the notification in the particular order: How to Build Bitsolive Transaction Now miner received all data required to serialize bitsolive transaction: Coinb1, Extranonce1, Extranonce2_size and Coinb2.Firstly we need to generate Extranonce2 (must be unique for given job_id!).Extranonce2_size tell us expected length of binary structure.Just be absolutely sure that your extranonce2 generator always produces extranonce2 with correct length!For example my pool implementation sets extranonce2_size=4, which mean this is valid Extranonce2 (in hex): 00000000.To produce bitsolive, we just concatenate Coinb1 + Extranonce1 + Extranonce2 + Coinb2 together.For following calculations we have to produce double-sha256 hash of given bitsolive.In following snippets I'm using Python, but I'm sure you'll understand the concept even if you're a rubyist!It is as simple as: \ import hashlib import binascii bitsolive_hash_bin = hashlib.sha256(hashlib.sha256(binascii.unhexlify(bitsolive)).digest()).digest() How to Build Merkle Root Following Python snippet will generate merkle root for you.

Use merkle_branch from broadcast and bitsolive_hash_bin from previous snippet as an input: import binascii def build_merkle_root(self, merkle_branch, bitsolive_hash_bin): merkle_root = bitsolive_hash_bin for h in self.merkle_branch: merkle_root = doublesha(merkle_root + binascii.unhexlify(h)) return binascii.hexlify(merkle_root) How to Build Block Header?Now we're almost done!We have to put all together to produce block header for hashing: version + prevhash + merkle_root + ntime + nbits + '00000000' + '000000800000000000000000000000000000000000000000000000000000000000000000000000000000000080020000' First zeroes are blank nonce, the rest is padding to uint512 and it is always the same.Note that merkle_root must be in reversed byte order.If you're a miner developer, you already have util methods there for doing it.For some example in Python see Bitsolive mining proxy source codes.Server Can Occasionally Ask Miner to Change Share Difficulty Default share difficulty is 1 (big-endian target for difficulty 1 is 0x00000000ffff0000000000000000000000000000000000000000000000000000), but server can ask you anytime during the session to change it: { "id": null, "method": "mining.set_difficulty", "params": [2]} This Means That Difficulty 2 Will Be Applied to Every Next Job Received From the Server.