Privacy-Preserving Updates to Anonymous Databases?

Suppose a medical facility connected with a research institution and the researchers can use the medical details of a patient without knowing the personal details. Thus the research data base used by the researchers must be anonymized (Sanitized). We can consider another problem in the area of census. Individuals give the private information to a trusted party (Census Bureau) and the census bureau must publish anonymized or sanitized version of data. So anonymization is done for privacy. Our works deals with privacy in database system.