The goals of this project were to remove the sensitivity of personally-identifiable information (PII) as a challenge to achieving interoperability, to share data that can be linked among organizations, to avoid adding specific data elements to data sharing agreements (DSAs) like Social Security numbers (SSNs), to reduce security risks, and to ensure an open-source concept for future development and costs savings.

We created a Solution for Identifying Linkage Keys (SILK) to remove barriers to interoperability based on open-source technology. SILK transforms an SSN or other sensitive value into a secure hashed value. Two or more partners can use SILK with the same Salt (i.e., key) to convert sensitive fields into secure hashed values. Partners can then link their data using the hashed values (instead of a sensitive value like SSN) while never sharing the sensitive value.