This document summarizes a lecture on security and privacy in cloud computing. It discusses the data outsourcing problem where clients store data on untrusted servers. It describes different approaches like proof of data possession and proof of retrievability. It then summarizes a research paper that aims to enable public verifiability, data dynamics, and stateless and blockless verification for auditing data stored in the cloud. The paper's approach uses a Merkle hash tree and signatures to allow a third party auditor to efficiently audit cloud data without accessing the data itself.