Apparatus for secure computation of string comparators

We present an apparatus which can be used so that one party learns the value of a string distance metric applied to a pair of strings, each of which is held by a different party, in such a way that none of the parties can learn anything else significant about the strings. This apparatus can be applied to the problem of linking records from different databases, where privacy and confidentiality concerns prohibit the sharing of records. The apparatus can compute two different string similarity metrics, including the bigram based Dice coefficient and the Jaro-Winkler string comparator. The apparatus can implement a three party protocol for the secure computation of the bigram based Dice coefficient and a two party protocols for the Jaro-Winkler string comparator which are secure against collusion and cheating. The apparatus implements a three party Jaro-Winkler string comparator computation which is secure in the case of semi-honest participants.