The document discusses privacy preserving techniques in data mining. It outlines various privacy preserving approaches like randomization, encryption, and anonymization. K-anonymization is described as an important anonymization technique that involves generalization and suppression of data to ensure each record is indistinguishable from at least k-1 other records. The document also reviews several research papers on privacy preserving data mining and discusses issues like homogeneity attacks with k-anonymization. A hybrid approach combining k-anonymization with perturbation is proposed to better protect sensitive data privacy.