Utilizing the recent technologies in the healthcare organizations is an important method so as to enhance the healthcare services [1–۳]. There is a massive demand on healthcare services although there is also a huge unavailability in healthcare professional for instance doctors, nurses and pharmacists. Furthermore, diseases are turn out to be challenging and it is indispensable to develop novel technologies for getting better the patients at the emergence conditions. Cloud based intelligent health monitoring system (CIHMS) system is presented to bring about a healthier solution for the patients at an emergency condition which lessens the problem of the patients to go to the hospital at each and every time. It as well lets the patients to repossess the health care information at the emergency condition devoid of going to the hospital directly. In the CHIMS, the patient health information is identi- fied by WBSN and kept in the cloud storage and it could be accessed by everywhere and all the time via internet. The healthcare organizations access the data stored in the cloud and give the medical prescriptions dependent upon the patient health details [4]. The data collected by sensor networks and medical prescriptions given by healthcare organizations are extremely subtle and it must be managed properly for guaranteeing patient privacy. Accordingly, it is essential to guarantee the data security all through transmission and similarly storage in the cloud environment. Real-world problems such as security management and scalability with the data size should be focused. Keyaggregate cryptosystem [5] is one among the public-key cryptosystems, which encrypts the message by utilizing public key and likewise with an identifier of cipher text known as class. The key holder contains a master secret key, which is used to take the secret keys for several classes. The extracted key is an aggregated key that is a trampled as a secret key for single class [6]. In this research, scalable and enhanced key-aggregate cryptosystem (SE-KAC) is introduced to offer effective security for healthcare information with high scalability. In this method, Patient and health care organizations record the health data and medical prescriptions in the encrypted format. The double encryption technique is utilized for encrypting the data and furthermore the cipher text id known as classes is utilized. The key owner contains a master secret key, which is utilized to take out the secret keys for several classes. The extracted secret key is combined and compressed as a single key for decryption. Based on the size of the data, the cipher text is produced vigorously. At this point it produces the cipher text id dependent upon the size of the data.