An information flow analysis of recursive programs based on a lattice model of security classes

This paper shows a technique for efficiently analyzing the information flow of a program that generally includes recursive procedures. This technique enables security levels representing the secrecy of data to be assigned according to an arbitrary finite distributive lattice. This paper proves the soundness of the proposed information flow analysis method and shows that this algorithm can be executed in cubic order of the program description size. In addition, a congruence relation is used to extend the algorithm so that functions can be appropriately introduced to enable information within arguments to be hidden. Finally, a prototype system is used to present execution results of the proposed algorithm. © 2004 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 87(9): 48–61, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.20099