Chu-Hsing Lin

A flexible biometrics remote user authentication scheme

Abstract Recently, Lee, Ryu and Yoo proposed a fingerprint-based remote user authentication scheme by using smart cards and biometrics. Their scheme is based on two tiers of ElGamals private key cryptosystem and fingerprint verification. The scheme is novel by introducing biometrics verification technology into authentication scheme using smart cards. In this paper, we point out that their scheme is vulnerable to masquerade attack. We propose a new scheme to enhance their security. Furthermore, by using our scheme, users can conveniently choose and change their passwords. Our scheme is suitable for applications with high security requirement.

Research note: Threshold signature schemes with traceable signers in group communications

We propose a new group-oriented (t,n) threshold signature scheme that can withstand conspiracy attacks without attaching a secret number. The groups public key is determined by all members, each member signs a message independently and transmits the individual signature to a designated clerk who checks and integrates them into a group signature. A verifier can authenticate the group signature and trace back to find the signers. Further, we develop another threshold signature scheme without a trusted center. The proposed schemes possess all of the characteristics listed in Harns scheme and are more difficult to break.

Genetic Algorithm for Shortest Driving Time in Intelligent Transportation Systems

The route guidance system, which provides driving advice based on traffic information about an origin and a destination, has become very popular along with the advancement of handheld devices and the global position system. Since the accuracy and efficiency of route guidance depend on the accuracy of the traffic conditions, the route guidance system needs to include more variables in calculation, such as real time traffic flows and allowable vehicle speeds. As variables considered by the route guidance system increase, the cost to compute multiplies. As handheld devices have limited resources, it is not feasible to use them to compute the exact optimal solutions by some well- known algorithm, such as the Dijkstras algorithm, which is usually used to find the shortest path with a map of reasonable numbers of vertices. To solve this problem, we propose to use the genetic algorithm to alleviate the rising computational cost. We use the genetic algorithm to find the shortest time in driving with diverse scenarios of real traffic conditions and varying vehicle speeds. The effectiveness of the genetic algorithm is clearly demonstrated when applied on a real map of modern city with very large vertex numbers.

Comments on Saeednia's improved scheme for the hill cipher

Abstract In 2000, Saeednia proposed a new scheme to make the Hill cipher secure. The author makes use of permutations of columns and rows of a matrix to get a different key for encrypting each message. This paper shows that the cipher key Ht can be obtained by parameter u. Besides, the Saeednias scheme costs a lot of time in matrix computation. To overcome the drawbacks of Saeednias scheme, a more secure cryptosystem with a one‐way hash function is proposed.

Secret sharing with access structures in a hierarchy

We propose a secret sharing scheme with the property of access structures in a hierarchy. We employ the concept of admission tickets to delegate the access right from ancestors to their descendants. Each participant group has an authorized access structure and each access structure has its own secret key. The presented scheme is based on general hierarchies, and may be more suitable for real applications.

Anomaly Detection Using LibSVM Training Tools

Intrusion detection is the means to identify the intrusive behaviors and provides useful information to intruded systems to respond fast and to avoid or reduce damages. In recent years, learning machine technology is often used as a detection method in anomaly detection. In this research, we use support vector machine as a learning method for anomaly detection, and use LibSVM as the support vector machine tool. By using this tool, we get rid of numerous and complex operation and do not have to use external tools for finding parameters as need by using other algorithms such as the genetic algorithm. Experimental results show that high average detection rates and low average false positive rates in anomaly detection are achieved by our proposed approach.

Fast algorithms for common-multiplicand multiplication and exponentiation by performing complements

The multiplications of common multiplicands and exponentiations of large integers with large modulus are the primary computation operations in several well-known public key cryptosystems. The Hamming weight of the multiplier or the exponent plays an important role for computation efficiency. By performing complements, the Hamming weight of an integer can be reduced. Based on this concept, we propose efficient algorithms for common-multiplicand multiplications (CMM) and exponentiations. In the average case, it takes k/2+2/spl times/log(k)+5 k-bit additions to compute the CMM. For exponentiation, the proposed method takes 5k/4+2 multiplications on average, but the pre-computation for a modular multiplicative inverse is required. Combining the original CMM, the number of multiplications can further be reduced to 9k/8+2.

Energy Analysis of Multimedia Video Decoding on Mobile Handheld Devices

Video applications on mobile handheld devices are very challenging mainly due to the complex computational needs of video decoding and the limited capacity of batteries of handheld devices. The increasing number of codecs makes the situation even more perplexing for users trying to find the optimal video codes for playing on handheld devices. In this paper, we try to find the optimal video codecs from energy analyses of them on handheld devices. Various experiments have been done to investigate the effects from choices of codecs, file formats, and codec parameters.

A new public-key cipher system based upon the diophantine equations

A new public-key (two-key) cipher scheme is proposed in this paper. In our scheme, keys can be easily generated. In addition, both encryption and decryption procedures are simple. To encrypt a message, the sender needs to conduct a vector product of the message being sent and the enciphering key. On the other hand, the receiver can easily decrypt it by conducting several multiplication operations and modulus operations. For security analysis, we also examine some possible attacks on the presented scheme. >

Secure one-round tripartite authenticated key agreement protocol from Weil pairing

In 2000, Joux proposed a one-round protocol for tripartite Diffie-Hellman. In 2003, Shim presented an efficient one-round tripartite authenticated key agreement protocol based on Weil pairing to resist the man-in-the-middle attack appears in Jouxs. In this paper, we show that Shims protocol still cannot withstand the insider attack and the key-compromise impersonation attack. We propose a secure one-round tripartite authenticated key agreement protocol to solve the existed problems.