Secure Data Storage in Cloud: An e-Stream Cipher-Based Secure and Dynamic Updation Policy

With the growth of www, cloud computing paradigm has become a massive computing environment as a pay-per-use model to the user with shared pool of resources. It also provides on time demand services from anywhere anytime as instant updating and elasticity with measured services. Along with these services, cloud model has major security concerns as securing crucial data of user and maintaining integrity of VM's disk for consistent updation and retrieval from different sources. To achieve instant and secure migration of VMs, cloud service provider has introduced a concept of virtualization to maintain virtualized servers, OS, storage, etc. To achieve secure virtualization and dynamic updation of data in VM's disks, we introduce a model named secure e-stream cipher-based encryption/decryption as ChaCha20 method for maintaining proper security to the user's sensitive data at cloud data center. To maintain proper integrity and authenticity between VM's disks, a new methodology named dynamic version of dynamic Merkle hash B+ tree (DMBHT) with q-SDH secure short signature without random oracle signature scheme has been introduced. This scheme has efficient rate as erasure code (Tornado-z code) for forming block tag at leaf level of DMBHT. Our proposed methodology along with DMBHT has worst case complexity as instead of O(n) and has better public auditability to attain expeditious and secure modifications with proper updations.