Privacy preserving: To ensure that TPA cannot retrieve the data content during the auditing process. Lightweight: To allow TPA to perform auditing with minimum communication and computation overhead.
Arasu, S. E., Gowri, B., & Ananthi, S. (2013). Privacy-Preserving Public Auditing In Cloud Using HMAC Algorithm. International Journal of Recent Technology and Engineering, 2(1), 149–151.