Complete fairness in secure two-party computation

In the setting of secure two-party computation, two mutually distrusting parties wish to compute some function of their inputs while preserving, to the extent possible, various security properties such as privacy, correctness, and more. One desirable property is fairness , which guarantees that if either party receives its output, then the other party does too. Cleve (STOC 1986) showed that complete fairness cannot be achieved in general in the two-party setting; specifically, he showed (essentially) that it is impossible to compute Boolean XOR with complete fairness. Since his work, the accepted folklore has been that nothing non-trivial can be computed with complete fairness, and the question of complete fairness in secure two-party computation has been treated as closed since the late '80s.

Authors

• S. Dov Gordon
• Carmit Hazay
• Jonathan Katz
• Yehuda Lindell

Keywords

• cryptography
• fairness
• secure computation