Medical organizations find it challenging to adopt cloud-based Electronic Health Records (EHR) services due the risk of data breaches and resulting compromise patient data. Existing authorization models follow a patient-centric approach for EHR management, where responsibility authorizing access is handled at patients end. This creates significant overhead who must authorize every their health ...

We introduce the concept of attribute-based authenticated key exchange (AB-AKE) within the framework of ciphertext policy attribute-based systems. A notion of AKE-security for AB-AKE is presented based on the security models for group key exchange protocols and also taking into account the security requirements generally considered in the ciphertext policy attribute-based setting. We also exten...

In Ciphertext-Policy Attribute Based Encryption (CP-ABE), attributes are attached to the user's secret key and access policy is attached to the ciphertext. If attributes in the secret key of a user satisfy the policy then only the user can decrypt the ciphertext. However, such scenario also necessitates periodic updating of the secret key with the changing attributes. According to our obse...

This paper presents an ongoing work toward the proposal of the new concept of the attribute-based cryptosystem. In SCN2010, Gagné, Narayan, and Safavi-Naini proposed attribute-based signcryption (ABSC) with threshold structure. As in ciphertext-policy attribute-based encryption (CP-ABE), an encryptor can specify the access structure of decryptors, and as in attribute-based signature (ABS), each...

In this work, we provide the first construction of Attribute-Based Encryption (ABE) for general circuits. Our construction is based on the existence of multilinear maps. We prove selective security of our scheme in the standard model under the natural multilinear generalization of the BDDH assumption. Our scheme achieves both Key-Policy and Ciphertext-Policy variants of ABE. Our scheme and its ...

Decentralizing attribute based encryption is a variant of multi-authority attribute based encryption which doesn’t require a trusted central authority to conduct the system setup. In this paper, we propose an expressive decentralizing KP-ABE scheme with constant ciphertext size. In our construction, the access policy can be expressed as any non-monotone access structure. Meanwhile, the cipherte...