程序功能的局限性与密码系统

软件开发过程实际上是"问题空间"向"方案空间"的转换过程。根据"问题空间"和"方案空间"的特点,对它们的表示方法进行了抽象,并从一些有代表性的问题入手,对有关程序功能的局限性进行了分析和讨论。由得出的结论可知:无论程序设计语言如何进步,只要最终的实际计算机是基于图灵机模型,则程序的功能总具有局限性,即存在大量不可判定的程序。这从理论上说明了基于"不可计算性"的密码系统的可行性,并为此给出了一个设想方案。

Programming limitation and cryptosystem

Developing a software is actually a transformation from the "problem space" to the "solution space". The representations of the "problem space" and "solution space" were abstracted from their characteristics, and the limitations of the programming were discussed from several typical problems. The reached conclusion shows that no matter how advanced the programming language is, if the real computer is based on the model of "Turing machine", the ability of the program will always be limited, i.e. there are many undecidable programs. Therefore, the cryptosystem which based on the uncomputability is feasible, and an idea of such cryptosystem was proposed.