Zcash, an Untraceable Bitcoin Alternative, Launches in Alpha
By Andy Greenberg for Wired.com,
BITCOIN MAY HAVE become the currency of choice for the anonymity-loving Internet underground. But it’s never been anonymous enough for Zooko Wilcox. As he’ll remind anyone who’ll listen, the blockchain, bitcoin’s very public ledger of all transactions in its crypto-economy, means that unless bitcoin’s users funnel it through intermediaries or special software, their transactions can easily be traced.
Today Wilcox and his startup Zcash are launching the first public alpha release of the cryptography world’s best shot yet at perfectly untraceable digital money. Using a mathematical sleight-of-hand known as a “zero-knowledge proof,” Zcash (until recently known as Zerocoin or Zerocash) offers the same anti-forgery assurances as bitcoin: No one can counterfeit Zcash, or spend the same Zcash “coin” twice. But thanks to its zero-knowledge feature, any spender or receiver can also choose to keep their Zcash payment entirely secret.
The company holds the potential to empower a new form of near-perfect financial privacy—or, put in the terms of less friendly financial regulators, to enable a new form of airtight money laundering. “Consumers want to buy and sell things over the Internet and need privacy from snoops who might use the knowledge of their transactions against them,” says Wilcox, a 41-year-old cryptographer who’s also known in the crypto community for creating Tahoe LAFS, a decentralized, encrypted file-storage system. “This is the first time you can transact with anyone on the Internet, and control over who gets to find out about those transactions is solely in your hands.”
On Wednesday morning Zcash published its source code on Github, and is now allowing anyone to test out the software in what Wilcox calls a “preview.” But in an interview with WIRED he warns that the data moving on the Zcash network doesn’t yet represent actual money, only a “test net” that’s designed to give Zcash a chance to iron out its bugs before anyone makes investments in the cryptocurrency. Wilcox estimates the “real money” launch of Zcash is likely still close to six months away. The prototype version of Zcash that WIRED downloaded still lacked a user interface and instead required figuring out a tough-to-navigate set of command line functions.
Like bitcoin, Zcash’s currency will be created by “mining” computers that compete to solve mathematical problems. But unlike bitcoin and other attempts to create an alternative cryptocurrency or “altcoin,” Zcash is launching as a for-profit company. For its first four years online, a portion of every mined Zcash coin will go directly to Wilcox’s Zcash company and a smaller portion to a non-profit he’s creating to oversee the Zcash code and community longterm. Wilcox says that he plans for 1 percent of Zcash’s currency to ultimately go towards that non-profit, and 10 percent to be paid to the for-profit startup.
That for-profit strategy, Wilcox says, was designed to raise money to fund the project: Much of the 10 percent it earns will repay Wilcox’s investors, who as of November had put more than $715,000 into Zcash. Those investors include Naval Ravikant, an investor in Twitter and Uber, Barry Silbert, the founder of startup equity-trading platform SecondMarket, and Roger Ver, a staunch libertarian who’s invested in bitcoin startups Blockchain.info and Bitpay, and who also bankrolled much of the legal defense of now-convicted Silk Road creator Ross Ulbricht. (Wilcox says that Zcash remains on the sidelines of the schism over bitcoin’s scalability and speed that’s currently splitting the cryptocurrency community, though he hopes it will be able to integrate any upgrades to bitcoin’s code that solve those issues.)
Plenty of cryptocurrencies that have boasted features bitcoin lacks have launched and languished over the years, without seeing even a fraction of bitcoin’s adoption. But Wilcox argues that Zcash’s incognito properties, when the currency finally does launch for public consumption and real financial applications, will be crucial for those who need a more privacy-preserving form of digital money. That includes anyone from a medical startup trying to comply with healthcare privacy laws to a businesswoman in Afghanistan dodging corrupt cops and tyrannical male family members. “Privacy makes whole societies safer, stronger and more prosperous,” says Wilcox. “Ubiquitous privacy helps prevent corruption and abuse and oppression.”
Of course, the sort of “ubiquitous privacy” that Zcash is designed to allow will no doubt find fans within black markets, too, like the dark web’s $100 million-a-year drug trade. Until now, bitcoin’s lack of connection to banks or registered services has made it a convenient tool to spend money online without necessarily tying that money to the user’s identity. But the blockchain’s privacy problems have remained a nagging threat to anyone who makes a drug deal using bitcoin’s digital cash. Prosecutors proved bitcoin’s shortcomings for narco-money-laundering applications last year, for instance, when they traced $13.4 million from the drug site Silk Road to Ross Ulbricht’s laptop.
Zcash’s untraceability features promise to remove that sort of blockchain analysis as a tool for law enforcement surveillance. That notion has created controversy around the currency since it was first proposed by a team of cryptographers at Johns Hopkins University Back then, the anti-money-laundering think tank Global Financial Integrity published an op-ed in the Baltimore Sun describing the idea as a boon to black markets of all kinds, from human trafficking to wildlife poaching. “More girls will be sold as sex slaves, more rhinos will be poached, and every other large-scale transnational crime that you can name is going to become a lot easier if criminals have a way to transfer very large amounts of money completely anonymously,” wrote the group’s spokesperson E.J. Fagan.
Wilcox maintains his stealthy digital cash startup isn’t intended to facilitate crime, but also notes that the company isn’t liable for any criminal applications for which Zcash is used. “The people who built the first cars weren’t held responsible for car accidents or bank robberies,” he says. “The people who use these tools for good or ill are held responsible for that.”
But Wilcox also insists that Zcash’s legitimate applications will outweigh its shady ones. He compares Zerocoin’s ambiguous potential to that of the Internet itself. “Can the internet be used for crime? Yes, it can be, but that’s not what’s important about it.” Wilcox says. “I’m focused on the trillions of dollars of legitimate commerce that flow around the world.”
