The flip side of anonymity is risk, because the currencies that claim this feature mainly DigiCash and Mondex do not confirm each transaction with a central bank.

ECONOMIST: So many ways to pay online

In the last few years, there has been an ever-louder drumbeat of pundits saying the world is moving to eliminate cash, but the many businesses that have popped up in the hope this would come true--Bitbux, Digicash, CyberCash, Flooz, Netchex and PayPal, to name but a few--have found only limited success, or have died, or have been merged into other companies.

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