GHash.IO

GHash.IO

Trading name	GHash.IO
Industry	Mining Pool
Founded	October 2013
Defunct	October 24, 2016
Website	https://ghash.io

GHash.IO was a bitcoin mining pool operated in conjunction with the CEX.IO exchange. The pool offered bitcoin mining (with Namecoin merge-mining) and Litecoin mining (with Dogecoin merge-mining). It used a PPLNS reward scheme. At times it was among the largest pools on the network.

History

GHash.IO began operating around October 2013 and shared account credentials with CEX.IO, so the pool functioned as the mining side of that exchange. Users could buy cloud mining power denominated in GHS on CEX.IO and mine on GHash.IO until they sold that power.

In June 2014 the pool briefly approached or exceeded half of the bitcoin network hashrate, which raised community concern about 51% attack risk. After criticism, the operators publicly pledged to keep the pool's share below about 40 percent.

CEX.IO later scaled back related cloud mining amid low profitability. On October 24, 2016, CEX.IO announced that all mining on GHash.IO had stopped as of 12:00 GMT that day. CEX.IO continued as a cryptocurrency trading platform.

Connection with CEX.IO

GHash.IO and CEX.IO shared account credentials, so the pool functioned as the mining side of that exchange. Shared logins allowed simultaneous trading and mining. Mining power (GHS) purchased on CEX.IO mined on GHash.IO until the owner sold that power. After the pool closed in October 2016, CEX.IO continued as a separate cryptocurrency trading platform.

PPLNS

GHash.IO used PPLNS (“Pay per last N shares”), a reward scheme that pays shares in a window starting from the last share submitted and going backwards up to some number N of shares. Shares older than the window were not paid.