Muaz Ahmad

Salah Harb, M. Omair Ahmad, M. N. S Swamy

In this paper, a novel and efficient hardware implementation of steganographic cryptosystem based on a public-key cryptography is proposed. Digital images are utilized as carriers of secret data between sender and receiver parties in the communication channel. The proposed public-key cryptosystem offers a separable framework that allows to embed or extract secret data and encrypt or decrypt the carrier using the public-private key pair, independently. Paillier cryptographic system is adopted to encrypt and decrypt pixels of the digital image. To achieve efficiency, a proposed efficient parallel montgomery exponentiation core is designed and implemented for performing the underlying field operations in the Paillier cryptosystem. The hardware implementation results of the proposed steganographic cryptosystem show an efficiency in terms of area (resources), performance (speed) and power consumption. Our steganographic cryptosystem represents a small footprint making it well-suited for the embedded systems and real-time processing engines in applications such as medical scanning devices, autopilot cars and drones.

Minghao Ruan, Muaz Ahmad, Yongqiang Wang

Average consensus is fundamental for distributed systems since it underpins key functionalities of such systems ranging from distributed information fusion, decision-making, to decentralized control. In order to reach an agreement, existing average consensus algorithms require each agent to exchange explicit state information with its neighbors. This leads to the disclosure of private state information, which is undesirable in cases where privacy is of concern. In this paper, we propose a novel approach that enables secure and privacy-preserving average consensus in a decentralized architecture in the absence of any trusted third-parties. By leveraging homomorphic cryptography, our approach can guarantee consensus to the exact value in a deterministic manner. The proposed approach is light-weight in computation and communication, and applicable to time-varying interaction topology cases. A hardware implementation is presented to demonstrate the capability of our approach.