We show that the secrecy function conjecture that states that the maximum of the secrecy function of an l-modular lattice occurs at 1/ √ l is false, by proving that the 4-modular lattice C = Z⊕ √ 2Z⊕ 2Z fails to satisfy this conjecture. We also indicate how the secrecy function must be modified in the l-modular case to have a more reasonable chance for it to have a maximum at 1/ √ l, and show t...

We study ballot secrecy and ballot independence for election schemes. First, we propose a definition of ballot secrecy as an indistinguishability game in the computational model of cryptography. Our definition builds upon and strengthens earlier definitions to ensure that ballot secrecy is preserved in the presence of an adversary that controls the bulletin board and communication channel. Seco...

We consider the General Gaussian Multiple Access Wire-Tap Channel (GGMAC-WT). In this scenario, multiple users communicate with an intended receiver in the presence of an intelligent and informed eavesdropper who is as capable as the intended receiver, but has different channel parameters. We aim to provide perfect secrecy for the transmitters in this multi-access environment. Using Gaussian co...

In this paper, we investigate an opportunistic relay and jammer scheme along with relay selection algorithms based on the secrecy rate criterion in multiple-input multiple-output buffer-aided down link relay networks, which consist of one source, a number of relay nodes, legitimate users and eavesdroppers, with the constraints of physical layer security. The opportunistic relay and jammer schem...

This paper investigates secure transmission using HARQ protocol when the encoder only knows the statistics of the channel-state. We analyze the tradeoff between reliability and secrecy probabilistic guarantees. The conventional approach of ensuring the secrecy via introduction of dummy-message is followed. However, unlike the previous works on this subject, we design a coding strategy tailored ...

Received May 5 th , 2012 Revised May 31 st , 2012 Accepted June 2 nd , 2012 In open literature there is a lack of focus on Shannon‟s secrecy of ciphers as a security measurement of symmetric key encryption, hence in this research, Shannon‟s theories on secrecy of ciphers were used to calculate the average secrecy of each symmetric cipher used in this research. All secrecy and performance analys...