It is shown that, particularly for terrestrial cellular telephony, the interference-suppression feature of CDMA (code division multiple access) can result in a many-fold increase in capacity over analog and even over competing digital techniques. A single-cell system, such as a hubbed satellite network, is addressed, and the basic expression for capacity is developed. The corresponding expressions for a multiple-cell system are derived. and the distribution on the number of users supportable per cell is determined. It is concluded that properly augmented and power-controlled multiple-cell CDMA promises a quantum increase in current cellular capacity. >

On the capacity of a cellular CDMA system

From the Publisher:
Real-Time Systems is both a valuable reference for professionals and an advanced text for Computer Science and Computer Engineering students. 

Real world real-time applications based on research and practice

State-of-the-art algorithms and methods for validation

Methods for end-to-end scheduling and resource management

More than 100 illustrations to enhance understanding

Comprehensive treatment of the technology known as RMA (rate-monotonic analysis) methods

A supplemental Companion Website www.prenhall.com/liu

http://user.it.uu.se/~yi/courses/rts/dvp-rts-08/notes/Course-INFO.pdf

Real-Time Systems

Recently, in 2014, He and Wang proposed a robust and efficient multi-server authentication scheme using biometrics-based smart card and elliptic curve cryptography (ECC). In this paper, we first analyze He–Wang’s scheme and show that their scheme is vulnerable to a known session-specific temporary information attack and impersonation attack. In addition, we show that their scheme does not provide strong user’s anonymity. Furthermore, He–Wang’s scheme cannot provide the user revocation facility when the smart card is lost/stolen or user’s authentication parameter is revealed. Apart from these, He–Wang’s scheme has some design flaws, such as wrong password login and its consequences, and wrong password update during password change phase. We then propose a new secure multi-server authentication protocol using biometric-based smart card and ECC with more security functionalities. Using the Burrows–Abadi–Needham logic, we show that our scheme provides secure authentication. In addition, we simulate our scheme for the formal security verification using the widely accepted and used automated validation of Internet security protocols and applications tool, and show that our scheme is secure against passive and active attacks. Our scheme provides high security along with low communication cost, computational cost, and variety of security features. As a result, our scheme is very suitable for battery-limited mobile devices as compared with He–Wang’s scheme.

A Secure Biometrics-Based Multi-Server Authentication Protocol Using Smart Cards

As the most prevailing two-factor authentication mechanism, smart-card-based password authentication has been a subject of intensive research in the past two decades, and hundreds of this type of schemes have wave upon wave been proposed. In most of these studies, there is no comprehensive and systematical metric available for schemes to be assessed objectively, and the authors present new schemes with assertions of the superior aspects over previous ones, while overlooking dimensions on which their schemes fare poorly. Unsurprisingly, most of them are far from satisfactory—either are found short of important security goals or lack of critical properties, especially being stuck with the security-usability tension. To overcome this issue, in this work we first explicitly define a security model that can accurately capture the practical capabilities of an adversary and then suggest a broad set of twelve properties framed as a systematic methodology for comparative evaluation, allowing schemes to be rated across a common spectrum. As our main contribution, a new scheme is advanced to resolve the various issues arising from user corruption and server compromise, and it is formally proved secure under the harshest adversary model so far. In particular, by integrating “honeywords”, traditionally the purview of system security, with a “fuzzy-verifier”, our scheme hits “two birds”: it not only eliminates the long-standing security-usability conflict that is considered intractable in the literature, but also achieves security guarantees beyond the conventional optimal security bound.

Two Birds with One Stone: Two-Factor Authentication with Security Beyond Conventional Bound

An efficient and security dynamic identity based authentication protocol for multi-server architecture using smart cards

Improvement of the secure dynamic ID based remote user authentication scheme for multi-server environment

Weaknesses and improvements of the Yoon-Ryu-Yoo remote user authentication scheme using smart cards

Security enhancement on an improvement on two remote user authentication schemes using smart cards

Session initiation protocol (SIP) is a technology regularly performed in Internet Telephony, and Hyper Text Transport Protocol (HTTP) as digest authentication is one of the major methods for SIP authentication mechanism. In 2005, Yang et al. pointed out that HTTP could not resist server spoofing attack and off-line guessing attack and proposed a secret authentication with Diffie-Hellman concept. In 2009, Tsai proposed a nonce based authentication protocol for SIP. In this paper, we demonstrate that their protocol could not resist the password guessing attack and insider attack. Furthermore, we propose an ECC-based authentication mechanism to solve their issues and present security analysis of our protocol to show that ours is suitable for applications with higher security requirement.

Wei-Kuan Shih

Papers

Improvement of the secure dynamic ID based remote user authentication scheme for multi-server environment

Weaknesses and improvements of the Yoon-Ryu-Yoo remote user authentication scheme using smart cards

Security enhancement on an improvement on two remote user authentication schemes using smart cards

A Secured Authentication Protocol for SIP Using Elliptic Curves Cryptography

Secure mCoupons Scheme Using NFC