The amount of data that is transmitted across the internet is continuously increasing. With the transmission of this huge volume of data, the need of an encryption algorithm that guarantees the data transmission speedily and in a secure manner is a must. Hence, to achieve security in wireless networks, cryptography plays a very important role. In this paper, several hybrid combinations, which combines both symmetric and asymmetric cryptographic techniques to offer high security with minimum key maintenance is presented. This hybrid combination offers several cryptographic primitives such as integrity, confidentiality and authentication, thereby enhancing the security. Various combinations of Advanced Encryption Standard (AES), Elliptical Curve Cryptography (ECC) and Rivest, Shamir and Adleman (RSA) algorithms are used to provide hybrid encryption. Secure Hash Algorithm (SHA-256) is also used to provide authentication and integrity. The experimental results show that the proposed hybrid combinations gives better performance in terms of computation time compared to individual cryptographic schemes.

Emergency scenarios are very common in healthcare domain. These situations are very unpredictable and difficult to estimate the loss and amount of injuries or diseases that could occur. Hence it is impossible for the automated systems to detect these emergency situations and cannot provide the new information's. In case of elderly persons and patients who reside at home, need to check their healthcare record periodically using the systems. At times this becomes time consuming and inefficient to use and it could also happen that the person may forget to record or monitor the values periodically. Another scenario to be considered is when the patient is alone and not able to communicate the emergency situation to the family members and doctors. Hence to help and identify this situation we propose a flexible access control framework using Complex Event Processing (CEP) technology. When an emergency is detected the temporary access control policies (tacps) will be activated. These control policies will override the regular policies in emergency cases.

Abstract-In case of sharing the group of documents in cloud storage the document owners uses the encrypted key for secured sharing. For a single owner, the document contains one trapdoor key then the user can download it using the key, but for multiple owners this concept does not works. To overcome this practical problem this paper proposes a solution for KASE in case of federated clouds. This is a practice of interconnecting the cloud computing environment of two or more service providers for the purpose of load balancing traffic.