Ever since the alternative cryptocurrency Bitcoin launched, it’s had a known potential security flaw.If any single miner or collective group of miners (known as a pool) were ever able to account for 51% of the total hashing power on the network, those miners would be able to exert significant power over the entire blockchain.(See here for our intro primer to Bitcoin and an explanation for how the network functions).In five years, that’s never happened, because the BTC mining community has aggregated into a number of large players rather than a single network with disproportionate influence.Now, for the first time, that’s changed — Ghash.io passed the 51% mark for more than 12 hours this week, after promising to never do so back in January.This could be potentially devastating to the stability and reliability of the world’s most popular cryptocurrency.The record of all past Bitcoin transactions is known as the blockchain, but this information isn’t stored in any central server.

The blockchain is stored across multiple pools and continuously checked and rechecked.Periodically, a mining pool will mine a block that isn’t part of the conventional blockchain — this is known as an orphan block.buy bitcoins xapoWhen the orphaned block is validated against the pre-existing blockchain, it will be discovered and tossed out of the pool.bitcoin exchange founder deadThe diagram below shows this process.bitcoin kurs 7 tageIn this graph, purple blocks are orphan blocks while the black blocks are the validated block chain.When two or more blockchains are presented for validation, the Bitcoin protocol declares that the valid blockchain is the blockchain that’s been worked on the most.bitcoin en caida libre

This is the flaw in Bitcoin’s armor — any attacker that can account for 51% of the network’s total hashing power can create their own blockchain and pour work into it faster than the main blockchain updates.litecoin mining macOne of the chief problems with this is that the 51% network can double-spend coins by simply removing the transactions from its own blockchain after spending them (thereby returning the coins to the original user’s wallet).A mining pool with control of 51% of the network hash rate can make certain addresses unspendable by rejecting transactions aimed at those addresses.litecoin ltc chartIt can drive other pools out of business by refusing to incorporate their data, thereby orphaning their blocks.bitcoin china baiduWhile most of these behaviors make no sense for anyone who cares about Bitcoin’s future, unscrupulous investors and those seeking a quick get-rich payday have plenty of reason to subtly degrade their competitors’ performance.Ghash.io has refused requests for comment and has not addressed this concern directly.Ghash’s breaking the 51% mark has so far resulted in a sustained DDOS attack against the network from some corners (perpetrators unknown), and calls to fork the Bitcoin standard in others.bitcoin consensus protocol

Researchers Ittay Eyal and Emin Gün Sirer have published a blog post in which they argue that this latest event represents a complete breakdown in Bitcoin’s trustworthiness.bitcoin ticker gadgetAs they note, the website in question already has been caught red-handed in engaging in double-spend attacks.“The Bitcoin narrative, based on decentralization and distributed trust, has collapsed.This is far more important than the Bitcoin economy, which is about as healthy as it was yesterday, and the Bitcoin price, which will likely remain afloat for quite a while.But the Bitcoin economy and price are trailing indicators.The core pillar of the Bitcoin value equation has collapsed.”The short-term response from the Bitcoin mining community will likely be to attempt to block Ghash.io from accounting for quite so much mining firepower.The longer-term action is unclear.Some of the techniques that a 51% miner can exploit can themselves be fixed.

Pooled mining could be disincentivized, and though this is incredibly unlikely to happen (it would destroy the financial model the entire cryptocurrency industry is based on) it might be the best long-term solution.This is the type of deep structural problem that could bring Bitcoin down entirely.If Ghash.io continues gathering mining hardware, it will eventually be able to exert de facto control over the BTC standard.At that point, the difference between Bitcoin and the centralized fiat currencies it sought to replace would be largely eradicated, save that Ghash.io isn’t subject to the laws of any particular government nor the oversight that modern nations extend over the banking industries.As of this writing, DDOS attacks have knocked Ghash down to about 38% of total network hash rate.To account for 51% of the total network hash rate, Ghash had to be providing 58,120 THash/s.Let me put that in perspective.Bitcoin mining got its start on GPUs; in 2011, a Radeon 5970 (dual GPU) could crunch perhaps 700 MHash/s.

A modern Radeon R9 290X can do 800-900 MHash/s on a single card.The Radeon HD 7990 could crunch 1200-1300 MHash.To put this in perspective — you’d need more than 44 million Radeon 7990 cards to reach the current hash rates.Of course, that’s a ludicrous number — but this is why ASICs have surged into the gap.A modern Butterfly Labs ASIC box is $250 for 10 GHash/s — almost 10x faster than the HD 7990.[Read: AMD destroys Nvidia at Bitcoin mining, can the gap ever be bridged?]It makes racks of hardware like this look almost quaint.Hi,I have written a descriptive answer here How can I earn Bitcoins in India?Is it legal here?Please read.Isn't it amazing if tell you that you can print your own money ?Yes, you can create your own bitcoins and as much as you want and this can be done using you hardware or cloud services .Hardware Based MiningIn the initials days of Bitcoin mining , it was easily mined using the CPU .As the miners increased , to use more hash rates people started using GPU and now ASIC.

I am not going into the details on how this works in the background , you can refer to this Bitcoin mining if you want to know the science behind it.CPU/GPU MiningYou can use the hashrate of your own computer to mine bitcoins.But due to huge number of miners , difficulty of blockchain and high hash rates of ASIC its nearly impossible to mine Bitcoin for profitability.How can you compete with your 100H/s against 1TH/s ?If you have free electricity then you can get some sort of profit.Where as you can mine Altcoins or Alternative Cryptocurrencies such as Monero , Bytecoins , DASH , Ethereum etc.You can wait for them to turn into Gold or you can convert them to Bitcoin using Cryptonator.All you need to do is Register,Download Minergate GUI Miner for Windows/Linux and start mining.They also offer “Smart Miner” which automatically mines altcoins based on current exchange rates.ASIC MiningIf you have a high budget you can get yourself BITMAIN‘s Antminers which will cost 1000$ + which is around 80,000 INR.

You can calculate the profitability using Cryptocurrency Mining vs.Bitcoin Mining Profitability.Cloud Based Mining ServicesThis concept is going rounds for last few years, there are certain mining companies who are offering cloud services.All you need to do is sign up at their websites and buy hashrates.They take onetime fee + daily maintenance fee and offer lifetime contracts / one/two year contracts.You can mine Bitcoins , Monero , Ethereum , Dash etc and you can calculate your profitability using Cryptocurrency Mining vs.Bitcoin Mining Profitability .But in this cloud mining sector , maximum companies are running scam like TeraBox - Cheapest Bitcoin Mining , so you have to choose very carefully .You can trust the below websites completely.Genesis-mining ( Use code mNpFUG for 3% discount)Hashflare.ioHashing24NiceHashAny Monero / Ethereum contract will give you 80% + Return on Investment and this is one of the reasons why huge number people are joining the mining business.As you are totally new and don't know much about mining better not to go into it now..As using a CPU will never mine a great and your CPU will be of no use if you start marking using that..