Given some deal of cards, it is possible to communicate your hand to another player without yet another player learning any of your cards. Every solution to this problem consists of a sequence of safe communications, an interesting new form of update. Certain unsafe communications turn out to be unsuccessful updates. Each communication can be about a set of alternative card deals only, and even...

In this expository paper we discuss a relatively new counterfeit coin problem with an unusual goal: maintaining the privacy of, rather than revealing, counterfeit coins in a set of both fake and real coins. We introduce two classes of solutions to this problem — one that respects the privacy of all the coins and one that respects the privacy of only the fake coins — and give several results reg...

Keeping secrets from parents is associated with depression and antisocial behavior. The current study tested whether keeping secrets from best friends is similarly linked to maladjustment, and whether associations between secrecy and maladjustment are moderated by the quality of the friendship. Adolescents (N = 181; 51% female, 48% white, non-Hispanic, 45% African American) reported their secre...