In this paper, we present the enhancement of a lightweight key-policy attribute-based encryption (KP-ABE) scheme designed for the Internet of Things (IoT). The KP-ABE scheme was claimed to achieve ciphertext indistinguishability under chosen-plaintext attack in the selective-set model but we show that the KP-ABE scheme is insecure even in the weaker security notion, namely, one-way encryption under the same attack and model. In particular, we show that an attacker can decrypt a ciphertext which does not satisfy the policy imposed on his decryption key. Subsequently, we propose an efficient fix to the KP-ABE scheme as well as extending it to be a hierarchical KP-ABE (H-KP-ABE) scheme that can support role delegation in IoT applications. An example of applying our H-KP-ABE on an IoT-connected healthcare system is given to highlight the benefit of the delegation feature. Lastly, using the NIST curves secp192k1 and secp256k1, we benchmark the fixed (hierarchical) KP-ABE scheme on an Android phone and the result shows that the scheme is still the fastest in the literature.

Enhancement of a Lightweight Attribute-Based Encryption Scheme for the Internet of Things

The security of node ID assignment scheme is the foundation of solving security problems in structured P2P systems. However, existing researches on the node ID assignment mechanism present one or more following problems: (1) Schemes just only focused on individual attack, but did not comprehensively analyze the security requirements of node ID assignment mechanism. (2) Schemes needed complex certificate management or met key escrow problem. (3) Almost all existing schemes required a trusted center to act as the single signer of node IDs, but it is very hard to find an absolutely trusted node in structured P2P system. As a result, none of existing schemes can prevent the single signer from being compromised or launching active attack. This paper firstly designs a threshold signature scheme based on secret sharing and certificateless public key cryptosystem without paring (CL-PKC-without-P). Based on that, it proposes a node ID assignment protocol which eliminates the three problems listed above. Using secret sharing technology, this protocol is able to resist the active attacks launching by less than t signer, where t is the threshold value. The results of analysis and simulation show that this protocol is more secure, efficient and scalable.

http://www.sersc.org/journals/IJSIA/vol9_no8_2015/35.pdf

Jian Yang

Papers

Leveraging Certificate-less Public Key Cryptosystem for Node ID Assignment in Structured P2P Systems