Abstract: “Cloud computing is location-independent computing, whereby shared servers provide resources, software, and data to computers and other devices on demand. It describes a new supplement, consumption, and delivery model for IT services based on the Internet. Details are abstracted from consumers, who no longer have need for expertise in, or control over, the technology infrastructure \"in the cloud\" that supports them. Cloud computing is still considered in its infancy, there are many challenging issues waiting for tackling. The cloud suffers much from data loss, privacy, security and revocation problems. To overcome these problems an efficient Knowledge Based - Click Point Authentication (KB-CPA) and Multi-Authority Ciphertext-Policy Attribute Based Encryption (MA-CP-ABE) is proposed with some modifications.”

Keywords: Fuzzy Identity Based Encryption (FIBE) ; Multi-Authority Attribute Based Encryption (MA-ABE); Key-Policy Attribute Based Encryption (KP-ABE); Click Point Authentication (CPA); Ciphertext-Policy Attribute Based Encryption (CP-ABE); Knowledge Based Authentication (KBA); Knowledge Based - Click Point Authentication (KB-CPA); Multi-Authority Ciphertext-Policy Attribute Based Encryption (MACP-ABE); Pseudo Random Key Generator (PRKG); Global Identifier (GID); Global Attribute List (GAL