Systems and methods may be used for establishing a link between user identifiers of different systems without disclosing specific user identifying information. One method includes generating a matching relationship based on double encrypted one or more first data sets of a first party system and double encrypted one or more second data sets of a second party system. The matching relationship indicates one or more links between match keys associated with the first party system and the match keys associated with the third party system. The method includes assigning bridge identifiers for user identifiers associated with the first party system and the user identifiers associated with the third party system based on the matching relationship.