Paper 2016/045

New Approaches for Secure Outsourcing Algorithm for Modular Exponentiations

Xi-Jun Lin, Lin Sun, Haipeng Qu, and Xiaoshuai Zhang


Outsourcing paradigm is one of the most attractive benefits of cloud computing, where computation workloads can be outsourced to cloud servers by the resource-constrained devices, such as RFID tags. With this paradigm, cloud users can avoid setting up their own infrastructures. As a result, some new challenges, such as security and checkability, are inevitably introduced. In this paper, we address the problem of secure outsourcing algorithm for modular exponentiations in the one-malicious version of two untrusted program model. We show that our proposed algorithm is more efficient than the state-of-the-art algorithms. On the other hand, we point out in this paper that the first outsource-secure algorithm for simultaneous modular exponentiations proposed recently is insecure, where the sensitive information can be leaked to the malicious servers. As a result, we propose a new and more efficient algorithm for simultaneous modular exponentiations. We also propose the constructions for outsource-secure Cramer-Shoup encryptions and Schnorr signatures which are also more efficient than the state-of-the-art algorithms.

Available format(s)
Publication info
secure outsourcing algorithmmodular exponentiationsone-malicious model
Contact author(s)
linxj77 @ 163 com
2016-01-19: received
Short URL
Creative Commons Attribution


      author = {Xi-Jun Lin and Lin Sun and Haipeng Qu and Xiaoshuai Zhang},
      title = {New Approaches for Secure Outsourcing Algorithm for Modular Exponentiations},
      howpublished = {Cryptology ePrint Archive, Paper 2016/045},
      year = {2016},
      note = {\url{}},
      url = {}
Note: In order to protect the privacy of readers, does not use cookies or embedded third party content.