Daniele Micciancio Erez Petrank Simulatable Commitments and Efficient Concurrent Zero-Knowledge. 140-159 2003 conf/eurocrypt/2003 EUROCRYPT http://link.springer.de/link/service/series/0558/bibs/2656/26560140.htm db/conf/eurocrypt/eurocrypt2003.html#MicciancioP03