This paper considers the problem of estimating the population proportion when the study variable is sensitive in nature. Some indirect randomized response techniques are proposed, which maintain the requirement of efficiency and protection of confidentiality. In addition to unbiasedly estimating population proportion and variance, an efficiency comparison is also carried out to examine the performance of the proposed techniques. It is found that the proposed technique is more efficient than Warner , and Christofides  techniques.
Journal of information & optimization sciences 26(3), pp.549-557