Shinsuke Tamura^1,, Shuji Taniguchi¹

To make e-society, e-governance and cloud computing systems be utilized more widely, this paper proposes a scheme to collect attribute values belong to same data holders and calculate functions of them without knowing correspondences between the attribute values and their holders or links among attribute values of same holders. Different from most of other schemes the proposed scheme is based on linear Mix-net that exploits secret key encryption functions such as linear equation based (LE-based) and multidimensional array based (MA-based) ones, therefore it can handle real numbers that appear in many important business and engineering applications efficiently in the same way as integers. In addition, anonymous tag based credentials used in the scheme ensure the correctness of calculation results. Although the scheme can calculate only linear combinations of attribute values when LE-based encryption functions are used, if they are replaced with MA-based ones, it can calculate also general polynomial functions of attribute values.

E-society, E-governance, cloud computing, privacy, homomorphic encryption functions, anonymous tag based credentials