Further observations on certificateless public key encryption

Certificateless public key encryption can be classified into two types, namely, CLE and CLE † , both of which were introduced by Al-Riyami and Paterson in Asiacrypt 2003. Most works about certificateless public key encryption belong to CLE, where the partial secret key is uniquely determined by an entity’s identity. In CLE † , an entity’s partial secret key is not only determined by the identity information but also by his/her (partial) public key. Such techniques can enhance the resilience of certificateless public key encryption against a cheating KGC. In this paper, we first formalize the security definitions of CLE † . After that, we demonstrate the gap between the security model of CLE † and CLE, by showing the insecurity of a CLE † scheme proposed by Lai and Kou in PKC 2007. We give an attack that can successfully break the indistinguishability of their CLE † scheme, although their scheme can be proved secure in the security model of CLE. Therefore, it does not suffice to consider the security of CLE † in the security model of CLE. Finally, we show how to secure Lai-Kou’s scheme by providing a new scheme with the security proof in the model of CLE †

Security of RFID systems - a hybrid approach

The use of RFID (Radio Frequency Identification) technology can be employed for tracking and detecting each container, pallet, case, and product uniquely in the supply chain. It connects the supply chain stakeholders (i.e.; suppliers, manufacturers, wholesalers/distributors, retailers and customers) and allows them to exchange data and product information. Despite these potential benefits, security issues are the key factor in the deployment of a RFID-enabled system in the global supply chain. This paper proposes a hybrid approach to secure RFID transmission in Supply Chain Management (SCM) systems using modified Wired Equivalent Encryption (WEP) and Rivest, Shamir and Adleman (RSA) cryptosystem. The proposed system also addresses the common loop hole of WEP key algorithm and makes it more secure compare to the existing modified WEP key process.

Offline grouping proof protocol for RFID systems

Several grouping proof protocols have been proposed over the years but they are either found to be vulnerable to certain attacks or do not comply with EPC Class-1 Gen-2 (C1G2) standard because they use hash functions or other complex encryption schemes. Also, synchronization of keys, forward security, proving simultaneity, creating dependence, detecting illegitimate tags, eliminating unwanted tag processing and denial-of-proof (DoP) attacks have not been fully addressed by many. Our protocol addresses these important gaps and is based on Quadratic Residues property where the tags are only required to use XOR, 128-bit Pseudo Random Number Generators (PRNG) and Modulo (MOD) operations which can be easily implemented on low-cost passive tags and hence achieves EPC C1G2 compliance.

Secure ownership transfer in multi-tag/multi-owner passive RFID systems

In this paper we propose a secure ownership transfer protocol for a multi-tag and multi-owner RFID environment. Most of the existing work in this area do not comply with the EPC Global Class-1 Gen-2 (C1G2) standard since they use expensive hash operations or sophisticated encryption schemes that cannot be implemented on low-cost passive tags that are highly resource constrained. Our work aims to fill this gap by proposing a protocol based on simple XOR and 128-bit Pseudo Random Number Generators (PRNG), operations that can be easily implemented on low-cost passive RFID tags. The protocol thus achieves EPC C1G2 compliance while meeting the security requirements. Also, our protocol provides additional protection using a blind-factor to prevent tracking attacks.

Image encryption based on compressed sensing and blind source separation

A novel image encryption scheme based on compressed sensing and blind source separation is proposed in this work, where there is no statistical requirement to plaintexts. In the proposed method, for encryption, the plaintexts and keys are mixed with each other using a underdetermined matrix first, and then compressed under a project matrix. As a result, it forms a difficult underdetermined blind source separation (UBSS) problem without statistical features of sources. Regarding the decryption, given the keys, a new model will be constructed, which is solvable under compressed sensing (CS) frame. Due to the usage of CS technology, the plaintexts are compressed into the data with smaller size when they are encrypted. Meanwhile, they can be decrypted from parts of the received data packets and thus allows to lose some packets. This is beneficial for the proposed encryption method to suit practical communication systems. Simulations are given to illustrate the availability and the superiority of our method.

Secure distributed deduplication systems with improved reliability

Data deduplication is a technique for eliminating duplicate copies of data, and has been widely used in cloud storage to reduce storage space and upload bandwidth. However, there is only one copy for each file stored in cloud even if such a file is owned by a huge number of users. As a result, deduplication system improves storage utilization while reducing reliability. Furthermore, the challenge of privacy for sensitive data also arises when they are outsourced by users to cloud. Aiming to address the above security challenges, this paper makes the first attempt to formalize the notion of distributed reliable deduplication system. We propose new distributed deduplication systems with higher reliability in which the data chunks are distributed across multiple cloud servers. The security requirements of data confidentiality and tag consistency are also achieved by introducing a deterministic secret sharing scheme in distributed storage systems, instead of using convergent encryption as in previous deduplication systems. Security analysis demonstrates that our deduplication systems are secure in terms of the definitions specified in the proposed security model. As a proof of concept, we implement the proposed systems and demonstrate that the incurred overhead is very limited in realistic environments.