Secure Multiparty Computations Without Computers

Many simple calculations can be done easier without computers than by using them. We show that the same holds for secure multiparty computations if the function to be computed is simple enough. Our starting point is an observation of Bert den Boer: a multiparty computation of a logical ANDgate can be performed by ve simple playing cards. We show that by using a reasonable amount of cards many useful functions can be computed in such way that each input stays private. TUCS Research Group Mathematical Structures of Computer Science