Key Aggregation System for Secure Patient Health Record Using Cryptography

Patients personal health records (PHR) is coming into prominence which consist of the health information exchange which is to be stored on the cloud . Cloud Storage is the most popular technique used for storing data that come via internet. It consists of thousands of computers and servers which are linked together in network where all the files can be accessed or shared. One of the important functionality in cloud storage is data sharing. For this, the solution is the cryptography technique. Using cryptography we can securely store the data in the third party author i.e. cloud. For more security of the data we first encrypt the data and then store it on the cloud. The data must be shared only between the authorized people to avoid the leakage of confidential data. Before storing the PHR on the cloud through the internet it is always prefer that the data should be encrypted to avoid the unauthorized access. To make the data secure, the cryptosystem is being used is the key aggregate cryptosystem (KAC). This describe new public key cryptosystem technique which produces a constant-size n-cipher texts  such  that efficient delegation of decryption  for many distinct cipher texts are possible. The main concept is that one can aggregate many distinct Secret keys and make them compact like a single key, but it encompasses the power of all those keys being aggregated. The encryption can be done by the most popular algorithm called AES algorithm