DEPARTMENT OF MATHEMATICS AND COMPUTER SCIENCE               
                              ODENSE UNIVERSITY                              

                   And God said, ``let there be light'',...                  
               and Man said, ``can I have some dice as well?''               

                                 Rene Peralta                                
            Electrical Engineering and Computer Science Department           
                     University of Wisconsin at Milwaukee                    

                      Tuesday, May 21, 1996, at 2:15 PM                      
                                   Room 22                                   


We show how  to produce  short proofs  of theorems  such that  a distrusting
Verifier  can  be  convinced  that  the  theorem  is  true  yet  obtains  no
information about the  proof itself.  The  paper makes use  of what  we have
called ``set certification'', which consists of proving that a vector of bit
commitments encodes a vector  of bits in  a given set  without revealing the
bit-vector itself. We have high hopes for what useful results this technique
might eventually yield.  Since our shortest proofs  don't exactly fit any of
the published  categories  of  zero-knowledge proofs,  we  have  named  them
``discreet proofs''. As an example of the power of these techniques, we show
discreet proofs of knowledge of RSA and DES keys which fit on a floppy disk.

This is joint work with Joan Boyar.


                                                               Joan F. Boyar