LIKC: A liberty of encryption and decryption through imploration from K-cloud servers Kasturi Dhal a , Satyananda Champati Rai b , Prasant Kumar Pattnaik c a Department of CSE, Silicon Institute of Technology, Bhubaneswar, Odisha, India b Department of IT, Silicon Institute of Technology, Bhubaneswar, Odisha, India c School of Computer Engineering, KIIT University, Bhubaneswar, Odisha, India article info Article history: Received 28 August 2019 Accepted 23 January 2020 Available online xxxx Keywords: LIKC CPABE Cloud Imploration Revocation Data sharing Outsourcing abstract The technological advancement in the field of IoT and cloud computing along with the use of handheld gadgets generate huge amount of data. To process and share these data with fine-grained access control while maintaining confidentiality using cloud servers is a challenging task. Individuals as well as the organizations apprehend to use public cloud to share their private data due to security issues. Ciphertext-policy-attribute-based-encryption(CPABE) achieves one-to-many encryption with data confi- dentiality and fine-grained access control. Due to the computational intensive operations of encryption and decryption the performance of CPABE as a solution in resource-constraint environment is not encour- aging enough. Some of the existing models use the resources of cloud servers to carry out outsourced computation either with compromised security or with communication-overhead. To reduce the compu- tational time of encryption and decryption we propose a scheme LIKC which incorporates the outsourcing mechanism using a proxy server. With the imploration the computation time get reduced without com- promising the security. It also supports attribute-revocation to support flexible data sharing. The pro- posed model is implemented using python charm crypto. The output reveals that LIKC is able to produce promising results in comparison to the data sharing models for this study. Ó 2020 The Authors. Production and hosting by Elsevier B.V. on behalf of King Saud University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). 1. Introduction Cloud computing is a relatively new computing technology which delivers different types of internet based computing to the users. The cloud services used by a user are on pay per use basis without initial investment and management. The service providers facilitate storage service to the data owners to keep their data in the associated cloud servers. Storage as a service would be a prefer- able solution to process and share an organization’s huge amount of data with the specific group of employees. Due to privacy and security issues in the public cloud most of the organizations do not prefer storage as a service. Maintaining confidentiality, privacy as well as to share the uploaded data with fine-grained access con- trol are the major challenges of storage as service. 1.1. Motivation To overcome the challenges of privacy and security issues in the public cloud servers many researchers have proposed various data sharing models with an objective to improve the performance and security of existing models to make it deployable as real-life appli- cations. A significant number of recent research has been reported on attribute revocation scheme for data sharing model (Yang et al., 2013; Yang and Jia, 2014; Yang and Jia, 2014; Chen et al., 2016; Dhal et al., 2016b). Before uploading the data in the cloud server, it is encrypted by the data owner to maintain its confidentiality. Encrypted data are barriers to maintain fine grained access control as well as to carry out some computational operations without vio- lating the confidentiality. Homomorphic encryption (Alloghani et al., 2019; Al-Maytami et al., 2020) is one of the solutions for this problem in which the data is encrypted in such a way that opera- tions can be performed without compromising the confidentiality. Traditional encryption technique is not adequate to ensure confi- dentiality while sharing data with fine-grained access control using an untrusted remote server. While remote servers compute on user’s request, the confidentiality of the uploaded data is com- promised. Further, the traditional encryption techniques have sev- eral short comings. The data owner has to stay online to distribute the key in symmetric key encryption technique. If a data owner uses asymmetric key encryption algorithm then redundant copies of a file has to be kept for each authorized users which would be a costlier solution for the data owner. Further, it would be a great https://doi.org/10.1016/j.jksuci.2020.01.011 1319-1578/Ó 2020 The Authors. Production and hosting by Elsevier B.V. on behalf of King Saud University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). E-mail addresses: kdhal@silicon.ac.in (K. Dhal), satya@silicon.ac.in (S.C. Rai) Journal of King Saud University – Computer and Information Sciences xxx (xxxx) xxx Contents lists available at ScienceDirect Journal of King Saud University – Computer and Information Sciences journal homepage: www.sciencedirect.com Please cite this article as: K. Dhal, S. C. Rai and P. K. Pattnaik, LIKC: A liberty of encryption and decryption through imploration from K-cloud servers, Journal of King Saud University – Computer and Information Sciences, https://doi.org/10.1016/j.jksuci.2020.01.011