Name: Sumana Maiti Roll No: 15CS92P01
Thesis Title: Towards Lightweight and Anonymous Identity-based Broadcast Proxy Re- encryption
Thesis Abstract:
Broadcast Proxy Re-encryption (BPR) is a secure and effective way to share cloud data with a group of receivers to maintain the confidentiality of the data. However, there are different limitations such as an increase in the size of the security elements, an increase in the computation cost of users, and a violation of the identity privacy of the receivers. Addressing these issues in different applications is a challenging task.The computation cost of the sender and the receiver are inversely proportional to each other. We propose a scheme GROSE to balance the payoffs of both sides and to increase the total payoff of the overall system. We use a bargaining game to find the optimal number of receivers of the group of BPR.
The privacy of each receiver's identity is not maintained in the Broadcast Proxy Re- encryption. We propose a scheme P2B to provide privacy preservation of the identities of the receivers. P2B uses Lagrange Interpolation Polynomial Theorem to hide the identities of the receivers. Additionally, the proposed scheme reduces the decryption time of the receivers.
The data owner knows the identities of the receivers in Broadcast Proxy Re-encryption. On the other hand, Attribute-based Encryption allows fine-grained access control of the re-encrypted ciphertext. We propose a scheme ABP to share the data with a subgroup of a group of receivers, where the receiver's attribute list satisfies the access policy. We use coalitional games to reduce the total cost of the system.
BPR algorithm needs to calculate a separate re-encryption key and a separate re-encrypted ciphertext for separate data. We propose a scheme MBP to generate a single re-encryption key and a single re-encrypted ciphertext to share more than one data with a different group of receivers.
MBP uses a non-cooperative bargaining game to estimate how much data can be shared in a single re-encryption to avoid the increase of decryption cost.
We propose a scheme CBP to add new receivers to the existing group of receivers to avoid the re-calculation of the re-encryption key. We use coalitional game theory to determine how many users can be added to the existing group to reduce the decryption time of the existing receivers.
