Proxy re-encryption

About: Proxy re-encryption is a research topic. Over the lifetime, 708 publications have been published within this topic receiving 33624 citations.

A Multi-use CCA-Secure Proxy Re-encryption Scheme

Abstract: Proxy re-encryption (PRE) can be classified as single-hop PRE and multi-use PRE according to the times which the ciphertext is transformed. Finding a unidirectional, multi-use, and chosen ciphertext attack (CCA) secure PRE is presented as an open problem by Canetti et al. Wang claimed to resolve this problem by proposing the first multi-use CCAsecure unidirectional PRE scheme. But we found that different with single-hop PRE, multi-use PRE without randomize encrypt key in its re-encryption algorithm could be vulnerable to attack. A new type attack to multi-use CCA-secure PRE named proxy bypass attack is proposed with a concrete attacks on Wang-MultiUse-PRE scheme. This attack is also effective for other multi-use scheme. At last we propose an improvement for Multi-Use-PRE to resist proxy bypass attack by randomize re-encryption algorithm.

A Lightweight Proxy Re-Encryption Approach with Certificate-Based and Incremental Cryptography for Fog-Enabled E-Healthcare

Abstract: Cloud computing aims to provide reliable, customized, and quality of service (QoS) guaranteed dynamic computing environments for end-users. However, there are applications such as e-health and emergency response monitoring that require quick response and low latency. Delays caused by transferring data over the cloud can seriously affect the performance and reliability of real-time applications. Before outsourcing e-health care data to the cloud, the user needs to perform encryption on these sensitive data to ensure its confidentiality. Conventionally, any modification to the user data requires encrypting the entire data and calculating the hash of the data from scratch. This data modification mechanism increases communication and computation costs over the cloud. The distributed environment of fog computing is used to overcome the limitations of cloud computing. This paper proposed a certificate-based incremental proxy re-encryption scheme (CB-PReS) for e-health data sharing in fog computing. The proposed scheme improves the file modification operations, i.e., updation, deletion, and insertion. The proposed scheme is tested on the iFogSim simulator. The iFogSim simulator facilitates the development of models for fog and IoT environments, and it also measures the impact of resource management techniques regarding network congestion and latency. Experiments depict that the proposed scheme is better than the existing schemes based on expensive bilinear pairing and elliptic curve techniques. The proposed scheme shows significant improvement in key generation and file modification time.

Constant-size CCA-secure multi-hop unidirectional proxy re-encryption from indistinguishability obfuscation

Abstract: In this paper, we utilize the recent advances in indistinguishability obfuscation, overcome several obstacles and propose a multi-hop unidirectional proxy re-encryption scheme. The proposed scheme is proved to be CCA-secure in the standard model (i.e., without using the random oracle heuristic), and its ciphertext remains constant-size regardless of how many times it has been transformed.

Attribute-Based Proxy Re-encryption with Dynamic Membership

Abstract: Cloud computing has been developed rapidly in recent years, and offers novel concepts and innovations in computer use. The applications of cloud computing are that people can put their data on cloud and also can designate a proxy to help them to execute a number of tasks in certain situations. The proxy re-encryption which is a cryptographic primitive has been proposed to solve this problem. In the proxy re-encryption system, when a user (e.g., Alice) wants to send a cipher text that is encrypted by her public key and stored in the cloud to another user (e.g., Bob), she can designate a proxy to transform the cipher text into a different cipher text that can be decrypted by Bob's private key. Recently, Fan et al. Proposed an attribute-based encryption scheme with dynamic membership. However, we found that their scheme may be flawed. In this paper we will modify Fan et al.'s scheme to fix the flaw. Based on our modified scheme and the proxy re-encryption, we also propose an attribute-based proxy re-encryption under bilinear pairing. Furthermore, the proposed scheme has rich access policies and dynamic membership.