We will extend Reed's Semi-Strong Perfect Graph Theorem by proving that unbreakable C 5-free graphs diierent from a C 6 and its complement have unique P 4-structure.

An (m, n) threshold scheme is to decompose the master key K into n secret shadows in such a way that the master key K cannot be reclaimed unless any m shadows are collected. However, any m 1 or fewer shadows provide absolutely no information about K. In 1989, Laih et al. proposed the concept of dynamic threshold schemes which allow the master key to be updated without changing the secret shadow...

People can access and obtain services from smart home devices conveniently through fog-enabled environments. The security privacy-preserving authentication protocol play an important role. However, many proposed protocols have one or more flaws. In particular, almost all the existing for cannot resist gateway compromised attacks. adversary not only know user’s identity but also launch impersona...

<p style='text-indent:20px;'>A splitting BIBD is a type of combinatorial design that can be used to construct authentication codes with good properties. In this paper we show design-theoretic approach useful in the analysis more general codes. Motivated by study algebraic manipulation detection (AMD) codes, define concept <i>group generated</i> code. We all group-generated hav...

We consider a distributed secret sharing system that consists of dealer, n storage nodes, and m users. Each user is given access to certain subset where it can download the stored data. The dealer wants securely convey specific s j j via for j=1,2, ..., m. More specifically, two secrecy conditio...

The Wonderful Lemma, that was first proved by Roussel and Rubio, is one of the most important tools in the proof of the Strong Perfect Graph Theorem. Here we give a short proof of this lemma.

T his thesis studies physical layer security for multi-user multiple-input multiple-output (MIMO) wireless systems. Due to the broadcast nature of the physical medium, wireless multi-user communications are very susceptible to eavesdropping, and it is critical to protect the transmitted information. Security of wireless communications has traditionally been achieved at the network layer with cr...

Shannon’s notion of entropy remains a benchmark reference for understanding information and data content of cryptosystems. Ideally, secure ciphers maintain high entropy between possible plaintext ciphertext pairs. The one time pad, though perfectly secure in terms of entropy, remains impractical in most general cases due to key management issues. We discuss in this paper the similar notion of f...

Authenticated key exchange (AKE) protocol is an important cryptographic primitive that assists communicating entities, who are communicating over an insecure network, to establish a shared session key to be used for protecting their subsequent communication. Lattice-based cryptographic primitives are believed to provide resilience against attacks from quantum computers. An efficient AKE protoco...