Biblio

Ciphertext Policy Attribute Based Encryption techniques provide fine grained access control to securely share the data in the organizations where access rights of users vary according to their roles. We have noticed that various key delegation mechanisms are provided for CP-ABE schemes but no key delegation mechanism exists for CP-ABE with hidden access policy. In practical, users' identity may be revealed from access policy in the organizations and unlimited further delegations may results in unauthorized data access. For maintaining the users' anonymity, the access structure should be hidden and every user must be restricted for specified further delegations. In this work, we have presented a flexible secure key delegation mechanism for CP-ABE with hidden access structure. The proposed scheme enhances the capability of existing CP-ABE schemes by supporting flexible delegation, attribute revocation and user revocation with negligible enhancement in computational cost.

Unauthorized access of the data is one of the major threat for the real world digital data communication. Digital images are one of the most vital subset of the digital data. Several important and sensitive information is conveyed through digital images. Hence, digital image security is one of the foremost interest of the researchers. Cryptographic algorithms Biological sequences are often used to encrypt data due to their inherent features. DNA encryption is one of the widely used method used for data security which is based on the properties of the biological sequences. To protect the images from unwanted accesses, a new two stage method is proposed in this work. DNA Encryption and Polymerase Chain Reaction (PCR) Amplification is used to enhance the security. The proposed method is evaluated using different standard parameters that shows the efficiency of the algorithm.