A method and system for securely storing and accessing sensitive user data (e.g., personally identifying information or PII) is described. In an aspect, PII is divided into a plurality of separately stored data stores based on what type or field of PII are collected. Each piece of PII data or PII datum is associated with a unique code so as to form data pairs comprising the PII datum and the unique code associated with that PII datum. A tumbler data structure allows secure association of the unique codes for the PII data for each user. Once the tumbler data structure is unlocked, a provider can search and access the PII data of its users.