Sharing The Personal Health Records With Group-Oriented Attribute-Based Encryption Schemes

The Personal Health Records is applied as a modern information technology and has obvious advantage compared with the tradition way that record the Per-sonal Health Records.It is not only in favor of saving information but also viewing information from anywhere at anytime.To achieve this,patient can store his/her own Personal Health Records in the cloud and share with doctors or medical in-stitutions.In this way,the doctors and other medical institutions can know the patient’s health status in real time and can provide accurate and real-time aid or can aid the patient accurately and timely.In the era of mobile Internet,the way of obtaining the Personal Health Records changed with the widespread use of mobile equipments.Through the mobile equipment,the obtained personal health records become more comprehensive and more accurate.Because of the cloud comput-ing can provide available,convenient,on-demand network access,Personal Health Records are mostly stored and shared through the cloud service,But in the net-work environment,the security of the data is always faced with kinds of threats and challenges.In practice,the Personal Health Records contain sensitive person-al information.Thus,ensuring the confidentiality of Personal Health Records has the importance of self-evident.The use of cryptography technology can effectively ensure the safety of data and the attribute-based encryption scheme can be used in the Personal Health Records system under the cloud environment very well,but the attribute-based encryption has the property of collusion and cannot be used in the condition of group cooperation.In practice,however,it frequently happens that users need to merge their attributes in order to access the data.For example,it requires more than one doctors to decrypt the Personal Health Records in certain cases.Therefore,we study the group-oriented attribute-based encryption in the Personal Health Records system.In the Personal Health Records system under the cloud environment,we present three group-oriented attribute-based encryption schemes.The main research of this paper are as follows:1.In order to realize the safe sharing of group-oriented Personal Health Records under the cloud environment,this paper present a scheme called group-oriented ciphertext-policy attribute-based encryption with monotone access structure.The scheme can not only realize data confidentiality but also achieve fine-grained access control to the user.Users in the system are divided into different groups,each user only belonging to one group.Users in the same group can decrypt by cooperation,but users in the different groups cannot decrypt cooperatively.In our scheme,we provide the security proof and performance analysis.2.In the existing scheme of the group-oriented attribute-based encryption,the lin-ear secret sharing scheme is used in encryption and decryption.In the fourth chapter of this article scheme,the integer secret sharing scheme is used in en-cryption and decryption.In the linear integer secret sharing scheme,the cost of computation the secret sharing is less compared with the linear secret sharing on the finite field.The access control structure consists of and-gate and or-gate,and we call our scheme is group-oriented attribute-based encryption with expressive access structure.Additionally,we give the concrete algorithm and security proof.3.In order to reduce the ciphertext size and the number of bilinear computation:and enable the scheme can be used by the mobile device which with lower com-puting power and storage capacity,we propose a scheme called group-oriented ciphertext-policy attribute-based encryption with constant ciphertext size.In the proposed scheme,the ciphertext size is constant and the number of bilin-ear computation in decryption is also constant.Additionally,we provide the concrete algorithm,security proof and performance analysis.