Tsai-Hua Kang

Random graphic user password authentication scheme in mobile devices

Smart mobile terminal are an essential device in our life today. The user usually enters in the related words or draws a simple graphic on the touch screen as passwords for unlocking the screensaver. Although this way can provide users with simple and convenient security mechanism, the process would increase the risk of words or graphic information leakage under the strict security consideration. Usually for this type of keypad lock screen app you can only customize the simple pattern or swipe-to-unlock screen with a static image on a background image that you select to unlock your phone. Therefore, the interested parties could have a chance to eavesdrop the simple graphic pattern information in order to hacking the smart device for stealing the personal information. Due to lack of the proper identity authentication mechanism in the usually keypad lock screen app, this paper proposes a new graphic pattern protection mechanism for enhance authentication level in the keypad lock screen app field. By randomly changing the fixed position of the digital graphics that shows on the touch screen, the user can draw different graphic pattern every time based on the unique or backup PIN password to unlock the screen. Not only added the random graphic pattern authentication method indeed increase the personal secret information being stolen difficulty and complexity, it provides more security level than the traditional graphic pattern authentication in keypad lock screen as well.

Through-wall imaging for a two-dimensional perfectly conducting cylinder based on asynchronous particle swarm optimization

We introduce a microwave imaging technique that integrates the asynchronous particle swarm optimization (APSO) into through wall imaging (TWI) within the finite difference time domain (FDTD) model of the inverse scattering problem. The forward scattering equations are solved by the FDTD method is employed to calculate the scattered E fields. Based on the scattering fields, the inverse scattering problems are transformed into optimization problems. The ability of asynchronous particle swarm optimization (APSO) stochastic searching algorithm for shape reconstruction of a 2-D conducting target hidden behind a homogeneous building wall is demonstrated by using simulated backscattered fields. The APSO is a population-based optimization approach that aims to minimize the objective function between mimic measurements and computer-simulated data. Thus, the shape of perfectly conducting cylinder can be obtained by minimizing the objective function. Simulations show that APSO can successfully reconstruct the through-wall imaging for a perfectly conducting cylinder. In addition, the effect of Gaussian noise on the reconstruction is investigated.

The study for selecting the cloud service consignment performance in group decision of shared inventory resource in small-sized electronic industry

Use cloud service to share sales resource in small-sized electronic industry, it will allow the staffs to focus on its core business and thus helps it to become more competitive. This article intends to establish a set of indexes for evaluating outsourced cloud service systems in terms of three aspects, i.e. supply, demand and supervision. We then apply Analytic Hierarchy Process (AHP) to collect opinions of related group decision and adopt TOPSIS (Technique for Order Preference by Similarity to Ideal Solution) for the evaluation and ranking of the cloud service system providers.

The study for selecting the cloud service consignment performance in group decision of shared sales resource

Use cloud service to share sales resource in publishing, it will allow the staffs to focus on its core business and thus helps it to become more competitive. This article intends to establish a set of indexes for evaluating outsourced cloud service systems in terms of three aspects, i.e. supply, demand and supervision. We then apply Analytic Hierarchy Process (AHP) to collect opinions of related group decision and adopt TOPSIS (Technique for Order Preference by Similarity to Ideal Solution) for the evaluation and ranking of the cloud service system providers.

Enhanced keystroke dynamics authentication utilizing pressure detection

Current computer and information systems are now used in almost all aspects of our lives, especially in banking systems and network systems. Most of the times, many computer systems use the simple and common username/password or keystroke biometric scheme via a keyboard for authentication. However, those fixed secret information can be guessed easily using different methods such as network sniffer, social engineering, spyware, dictionary attack and brute force attacks, etc. Meanwhile, using the password-based solution suffers from many security flaws and usability limitations. Although the user adopts extreme measures such as changing of the password and using long and complex passwords to be efficient and secure, these are unfriendly and hard to memorize for the user. Therefore, a solution to this problem is the use of an alternative biometric authentication method called Keystroke Dynamics. It is one of the famous biometric technologies and can be yet provide ease of use and transparency to the user in addition to security robustness. Keystroke Dynamics allows to secure the authentication process by verifying the way of typing the static credentials such as typing behavior, typing period of time, etc. But the static behavior can be easy continuously monitoring the users activities. There is always a golden opportunity for attacker who is physically close to the machine to have access to it. This paper investigates the use of keystroke dynamics that is combined users typing pressure activities on keyboard. The proposed scheme utilizes the key press and release pressure to build random users typing profile. The research done on Dynamic Keystroke Pressure-Based is ability to provide continual identity verification during the whole time and has a high accuracy level which was obtained under strictly controlled conditions.

Near-field and far-field image reconstruction for a buried conducting cylinder

Comparison of image reconstruction by using near-field and far-field data for a buried conducting cylinder is investigated. A conducting buried cylinder of unknown shape scatters the incident wave in half space and the scattered near and far fields are measured. By using measured fields, the imaging problem is reformulated into an optimization problem and solved by the asynchronous particle swarm optimization. Numerical results show that the convergence speed and final reconstructed results by using near-field data are better than those obtained by using far-field data. Finally, it is worth noting that the present work provides not only comparative information but also quantitative information.

The study for selecting the cloud service consignment performance in group decision of shared inventory resource in traditional garments industry

Use cloud service to share inventory resource in traditional garments industry, it will allow the staffs to focus on its core business and thus helps it to become more competitive. This article intends to establish a set of indexes for evaluating outsourced cloud service systems in terms of three aspects, i.e. supply, demand and supervision. We then apply Analytic Hierarchy Process (AHP) to collect opinions of related group decision and adopt TOPSIS (Technique for Order Preference by Similarity to Ideal Solution) for the evaluation and ranking of the cloud service system providers.

A new mobile on-line mutual authentication scheme

In todays life, the mobile phone is an essential device for the modern human. The people play installed games in the mobile device to pass the time and express emotions. However, stand-alone off-line game may not require internet connection but pro-longed use predisposes bored. Therefore, multiplayer on-line game meets the needs of groups of human activity. In the almost multiplayer on-line games, the player through the mobile network registers an account and connects to game servers to recognize the validity of identity and groups. Meanwhile, the game servers have the ability to identity other plays and assemble different groups consisting of different players. But a single player can registers multiple accounts and joins the designated groups what they want to be. Meanwhile, the players must always be connected to the game server to require on-line players and groups information. These software authentication vulnerabilities could cause the unfair game between players, cheating circumstances and player profile leakage. This paper proposes a new mobile on-line game authentication mechanism which meets a small amount of user following ten players. The proposed mechanism takes advantage of the known public key technique to provide the players convenience of without any time connected to the game server. The player can acquire the unique public key information in the first game software download process. Hereafter, players can apply the public key technique to reach mutual authentication, communication encryption and user information protection functions.

Multi-objective optimization for UWB antenna array by GA algorithm

In this paper, a uniform circular antenna array (UCAA) combining genetic algorithm (GA) or asynchronous particle swarm (APSO) for finding out global maximum of multi-objective function in indoor ultra-wideband (UWB) communication system is proposed. The algorithm is used to synthesize the radiation pattern of the directional UCAA to reduce the bit error rate (BER), to increase received energy and channel capacity in indoor UWB communication system. Using the impulse response of multipath channel, the BER of the synthesized antenna pattern on binary antipodal-pulse amplitude modulation system can be calculated. Based on topography of the antenna and the shooting and bouncing ray/image techniques, the synthesized problem can be reformulated into a multi-objective optimization problem which would be solved by the GA and APSO. Numerical results show that the fitness value and convergence speed by APSO is better than those by GA. The results also show that for multi-objective problem APSO compared to GA can reduce the BER substantially. Moreover, APSO can get better results for both line-of-sight and non line-of-sight cases.