Kurrent, a new digital currency based on the Zerocoin Protocol, assures private financial transactions and full anonymity.
With Kurrent you can prove that you own a coin without revealing which one is yours. During first step called "mint" your coin goes into an accumulator and during the second step called "spend" one can prove that he owns a coin in the accumulator but doesn't have to indicate which particular coin is his.
MINT ALGORITHM
"Mint" transaction turns a public coin with transaction history into a completely private coin that is stored in an accumulator.
SPEND ALGORITHM
"Spend” transaction allows you to create a new coin that has no transaction history by proving that you own one of the coins in the accumulator.
Check it out: http://kurrentproject.com