Want some passive income? Japanese firm GMO announced on Friday that Cryptoknocker will let anyone with GPU chips mine Zcash (ZEC) and other equihash-based cryptos. The free-to-download software is designed for everyday computers that have NVIDIA graphics cards installed (GeForce 8 or later). GMO said in Sept. 28 statement that it will charge 2% of all cryptocurrencies harvested but said their fee should be offset by efficiencies gained from their mining methods. For potential miners who may be interested, no. 21-ranked ZEC is currently trading at $133 with market capitalization of $654 million. There are two attractive features of ZEC. First, Zcash is considered a privacy coin and has a very limited circulating supply of 4.9 million coins. Some industry observers believe Zcash is poised for huge gains over the next 10 years as governments around the world tighten restrictions on cryptos and users begin to place a premium on privacy and freedom to transact online. That's a major reason why ICO advisory firm Satis Group is extremely bullish on privacy coins such as Monero (XMR), Zcash, Dash (DASH) and PIVX since these coins are regulation-resistant. The firm predicts that by 2028, Zcash could gain 6,000% to $9,000 and higher from the current price of $133. But there's also some uncertainty for ZEC. China-based equipment manufacturer Bitmain, the dominant supplier of mining rigs, recently announced that it will introduce ASIC mining hardware for Zcash. It's unclear if the ZEC community will embrace specialized hardware such as ASICs to mine the coins and what other ramifications may transpire from Bitmain's entrance into the scene. Zcash has been a source of income for people living in jurisdictions that have limited infrastructure because miners can use general-purpose computers to harvest ZEC.[caption id="attachment_37882" align="aligncenter" width="1050"]GMO[/caption] Bitmain enjoys 75% market share of global shipments in crypto mining rigs and the Chinese conglomerate is not resting on its laurels, either. To stave off competition (from Samsung and other global manufacturers), it's developing hardware for equihash-based cryptocurrencies in order to continue its impressive growth rate. Bitmain filed for an initial public offering (IPO) in Hong Kong in September 2018 and its financial statements reveal 328% annual revenue growth since 2015. Bitmain's sales increased from $137 million in 2015 to $2.5 billion last year. It profited $1.2 billion in 2017 and boasted nearly 50% net margins, according to accounting firm KPMG. The company is expected to smash through those numbers in 2018 with expected profits (not revenue) of $2 to $3 billion this year. The upcoming IPO will likely value Bitmain at $15 billion or more. And that's why Bitmain is targeting GPU-friendly Zcash and other equihash-based cryptos with ASIC-powered rigs. In September, Samsung Electronics announced that it will manufacture ASIC chips for Squire, a Canadian crypto mining company. If Samsung's hardware gain traction with miners, it could place the South Korean conglomerate on a roadmap to steal Bitmain's market share and eat away at the Chinese company's 50% net margins.