We establish valid answers by tallying the number of times each unique answer is given and then only accepting answers observed from at least m people, where m is an application-specific parameter to set. In practice, prior work deems answers as 100% valid using blind trust (i.e., m = 1 person) [22] as well as more conservative answer validation schemes (i.e., m = 3 people) <cite>[3]</cite> .