In todays scenario, various organizations store their sensitive data in the cloud environment. Multiple problems are present while retrieving and storing vast amounts of data, such as the frequency of data requests (increasing the computational overhead of the server) and data leakage while storing. To cope with said problem, Attribute-Based Encryption (ABE) is one of the potential security and access control techniques for secure data storage and authorization. The proposed work divides into two objectives: (i) provide access to authorized users and (ii) secure data storage in a cloud environment. The improved ABE using Functional Based Stream Cipher (FBSE) is proposed for data storage. The proposed technique uses simple scalar points over a parabolic curve to provide multiparty authorization. The authorization points are generated and share only with the authorized recipients. The Shamir secret sharing technique generate the authorization points and 2D-Lagrange Interpolation is used to reconstruct the secret points from regular parabola. The proposed scheme has specified the threshold (Ts>3) legally authorized users to reconstruct the attribute-associated keys for decryption. The encryption of data is evaluated using Statistical analysis (NIST Statistical Test Suite, Correlation Coefficient, and Histogram) test to investigate image pixel deviation. The parameters like encryption and decryption are used for performance analysis, where an increase in the number of attributes for the authorization policy will increase the encryption time. The proposed scheme imposes minimal storage overhead, irrespective of the users identity. The security analysis evidence that it resists collision attacks. The security and performance analysis results demonstrate that the proposed scheme is more robust and secure.

翻译：在当前背景下，各类组织将敏感数据存储于云环境中。海量数据的检索与存储存在诸多问题，例如数据请求频率（增加服务器计算开销）以及存储过程中的数据泄露。为解决上述问题，属性基加密（ABE）是实现安全数据存储与授权的潜在安全访问控制技术之一。本研究工作分为两个目标：（1）向授权用户提供访问权限；（2）实现云环境下的安全数据存储。本文提出采用基于功能的流密码（FBSE）改进ABE方案用于数据存储。该技术通过在抛物线曲线上使用简单标量点来实现多方授权。授权点经生成后仅与授权接收方共享。采用Shamir秘密共享技术生成授权点，并利用二维拉格朗日插值法从常规抛物线重构秘密点。本方案设定合法授权用户的阈值（Ts>3）以重构属性关联的解密密钥。通过统计分析（NIST统计测试套件、相关系数与直方图）检验评估数据加密效果，以探究图像像素偏差。采用加密/解密等参数进行性能分析，结果表明授权策略属性数量的增加将延长加密时间。本方案产生的存储开销极小，且与用户身份无关。安全性分析证明该方案能抵抗碰撞攻击。安全性与性能分析结果表明，所提方案具有更强的鲁棒性与安全性。