Secure communication schemes

Derek Abbott, Gabor Schmera

Éva Ádámkó

Zhijun Han, Yu Zhang, Yiqing Zhou +1 more

In this paper, we study a secure communication scheme assisted by multiple distributed friendly users over fading channels. To defeat a malicious user, friendly users transmit artificial noise continuously regardless of whether the transmitter is sending signals or not. The idle nodes in wireless networks can be selected as friendly users to assist in achieving secure communications. Due to the different positions of friendly users relative to the malicious user and receiver, the assisting abilities of friendly users in secure communications are different. To explore the potential of friendly users, a metric factor is proposed in this paper to evaluate the assisting abilities of friendly users. Based on the evaluating results, an optimum user selection and power allocation scheme is designed to maximize the secure throughput under the power limit and secure constraint. Compared with the benchmark scheme, the proposed secure communication scheme is easy to implement. Moreover, according to the numerical results, the proposed scheme can improve the secure throughput by more than 16% compared with the benchmark scheme when the secure constraint is larger than 0.5.

Manual Hoerl

Wang Jian, Zhang Quan, Tang Chao-Jing

We present a quantum secure communication scheme using three-qubit W state. It is unnecessary for the present scheme to use alternative measurement or Bell basis measurement. Compared with the quantum secure direct communication scheme proposed by Cao et al . [H.J. Cao and H.S. Song, Chin. Phys. Lett. 23 (2006) 290], in our scheme, the detection probability for an eavesdropper's attack increases from 8.3% to 25%. We also show that our scheme is secure for a noise quantum channel.

Jong-Shin Chen, Cheng‐Ying Yang, Jenq-Foung JF Yao +2 more

For a secure communication, it enables the destination could successfully release the authentic information from the sender. At the meantime, a secure system protects the transmitted information from the eavesdroppers. Traditionally, the encryption, authorization and authentication schemes could be employed for protecting the eavesdroppers. However, the unexpected attacks have been continuously developed. It could not be avoided for the undesired attacks. According to Shannon's perfect communication, there exists an error-free cryptogram that could protect for the attacker. Hence, based on the secrecy rate, it is expected that the secure communication could be practical with physical-layer coding scheme. Besides, the coding scheme is not only to obtain a critical level of security, but also to achieve a lower decoding error. For a security concern, increasing the secrecy rate leads a higher level of security ability. However, it might suffer the system performance without bandwidth efficiency. Hence, the tradeoff between the security level and coding rate is important to lead a secure communication.