A method and system for a fair exchange of user information over a network
is disclosed. The method comprises the steps of: transmitting over the
network the user information encoded in association with a hidden value
selected as one of a plurality of values distributed in a sequence
wherein a difference between adjacent ones of said values increases and
decreases symmetrically about one of the values of a known order;
transmitting over said network a first set of the values and a last value
in the sequence, wherein the values in said first set have increasing
differences between adjacent ones of the values; and transmitting,
individually, and in response to receipt of the other user's values, the
remaining values in said sequence.