Developing trusted softwares has become an important trend and a natural choice in the development of software technology and applications, and software trustworthiness modeling has become a prerequisite and necessary means. To discuss and explain the basic scientific problems in software trustworthiness and to establish theoretical foundations for software trustworthiness measurement, combining the ideas of dynamical system study, this paper studies evolutionary laws of software trustworthiness and the dynamical mechanism under the effect of various internal and external factors, and proposes dynamical models for software trustworthiness, thus, software trustworthiness can be considered as the statistical characteristics of behaviors of software systems in the dynamical and open environment. By analyzing two simple examples, the paper explains the relationship between the limit evolutionary behaviors of software trustworthiness attributes and dynamical system characteristics, and interprets the dynamical characteristics of software trustworthiness and their evolutionary complexity.
Developing trusted softwares has become an important trend and a natural choice in the development of software technology and applications. At present, the method of measurement and assessment of software trustworthiness cannot guarantee safe and reliable operations of software systems completely and effectively. Based on the dynamical system study, this paper interprets the characteristics of be- haviors of software systems and the basic scientific problems of software trustworthiness complexity, analyzes the characteristics of complexity of software trustworthiness, and proposes to study the soft- ware trustworthiness measurement in terms of the complexity of software trustworthiness. Using the dynamical statistical analysis methods, the paper advances an invariant-measure based assessment method of software trustworthiness by statistical indices, and hereby provides a dynamical criterion for the untrustworthiness of software systems. By an example, the feasibility of the proposed dynamical statistical analysis method in software trustworthiness measurement is demonstrated using numerical simulations and theoretical analysis.