Most ancient Chinese padlocks are key-operated locks with splitting springs, and partially keyless letter-combination locks. They can be characterized based on the types of locks, the shapes of locks, the engravings of locks, the materials of locks, and the mechanisms of locks. Some locks and keys are not only very beautiful and artistic colorful, but also with various designs. As a result, a s...

Peyravian and Zunic (2000) proposed a password transmission scheme and a password change scheme over an insecure network. Their proposed solutions do not require the use of any symmetric-key or public-key cryptosystems. However, this article points out that their schemes have several security flaws for practical applications. A slight improvement on their schemes is proposed in this paper to re...

A certificate of authenticity (COA) is an inexpensive physical object with a random and unique structure S which is hard to nearexactly replicate. An inexpensive device should be able to scan object’s physical “fingerprint,” a set of features that represents S. In this paper, we explore the requirements that optical media such as DVDs should satisfy, to be considered as COAs. As manufacturing o...

Broadcast encryption is the process of delivering encrypted data through a secure channel, intended for multiple users, in which only the privileged users can decrypt the content. In a broadcasting system, all the intended recipients are required to be accommodated in an organized way, which is possible through an efficient key management scheme. An ideal Broadcast Encryption scheme should defi...

Channel reciprocity based key establishment techniques have attracted more and more attention from the wireless security research community for its easy implementation, low computational requirement, and small energy consumption. The basic idea of these techniques is to establish a shared key by utilizing the wireless channel reciprocity, i.e., the transmitter and receiver of one wireless link ...

Diffie –Hellman technique: extended to multiple two-party keys and one multi-party key Abstract: The two-party Diffie– Hellman (DH) key-exchanging technique is extended to generate (i) multiple two-party keys and (ii) one multi-party key. The participants in the former case exchange two public keys and generate 15 shared keys. Of these, 4 keys are called base keys, because they are used to gene...

Securing a wireless communication has generally a vital importance, particularly when this communication is in a hostile environment like in wireless sensor networks (WSNs). The problem is how to create cryptographic keys between sensor nodes to ensure secure communications. Limited resources of sensor nodes make a public key cryptosystem such as RSA not feasible. So, most solutions rely on a s...

7 With the support of cellular system a cellular-based mobile ad hoc network (MANET) offers promising communication scenarios while entails secure data exchange as other wireless systems. In this paper, we propose a novel decentralized key generation mechanism using shared 9 symmetric polynomials in which the base stations (BSs) carry out an initial key generation by a symmetric polynomial in a...

Since the earliest days of necessity for secret transmission of messages, which date back to thousands years BCE, different methods have been used to transfer the message between two parties. These days, systematic ways for transmitting secret information are used, and the fear of cracking the message is increasing with the development of breaking algorithms for different encryption techniques....

Knowledge of mathematical foundations of Cryptography is of paramount importance for students wanting to succeed in graduate degree programs in Computer Science with concentration in security. Cryptography, a relatively new field, has yet to establish a core set of topics and the optimal sequence of their presentation to prepare students for a career in the field of IT security. This paper pres...