Efficient recovery of secrets

In the guessing secrets game defined by Chung, Graham and Leighton [(2001)], player B has to unveil a set of c > 1 secrets that player A has chosen from a pool of N values. To discover the secrets, player B is allowed to ask a series of boolean questions. For each question asked, A can adversarially choose one of the secrets but once he has made his choice he must answer truthfully. Here we present a solution to the c = 2 guessing secrets game consisting in an error correcting code equipped with a tracing algorithm that, using the Viterbi algorithm as its underlying routine, efficiently recovers the secrets.