Abstract: Cloud computing provides an opportunity to scale the computing resources dynamically on the internet. Sharing these resources, in a secure and efficient manner with others, is an open challenge. In order to overcome these issues, we proposed an optimized and secure data sharing (OSDS) approach for data outsourcing onto the cloud. In our proposed work, we used chaotic standard map with proxy re-encryption to provide fast and easy data sharing. Chaotic standard map reduce the computational time cost of encryption and decryption, while proxy re-encryption (PRE) reduce heavy computation at the side of data holder and make the data sharing flexible and easy. Earlier, to preserve the confidentiality of userís data against cloud server, generally cryptographic methods are applied. However, these cryptographic methods possess computation overhead on the data holder for key distribution and data management. An existing approach named as EFADS, provide good solution for this but its computational time cost is more as compared to our proposed OSDS approach. We compared proposed OSDS method with EFADS data sharing approach and found that our proposed approach is 1.5 times efficient than EFADS. Our OSDS approach consumes approximately 66% less computational time cost as compared to previous approach.

Keywords: Chaotic Standard Map, Cloud computing, EFADS, OSDS, Proxy Re-Encryption.