Electrical computers and digital processing systems: support – Computer program modification detection by cryptography
Reexamination Certificate
2008-09-02
2008-09-02
Kincaid, Kristine (Department: 2139)
Electrical computers and digital processing systems: support
Computer program modification detection by cryptography
C713S189000, C713S193000, C713S194000, C713S167000, C713S164000, C707S793000, C707S793000, C707S793000, C707S793000
Reexamination Certificate
active
10654826
ABSTRACT:
Techniques for using a class loader to protect mobile code against a malicious host. The techniques include using the class loader to extend a class used by the mobile code such that a method is added to the code which authenticates the mobile code. When executed, the method provides a dynamic watermark that authenticates the code. The method may be encrypted until it is added to the code. One such method uses a static watermark in the code to determine whether the code has been modified.The techniques also include using a class loader to extend the class such that obfuscated symbolic names in the program that correspond to symbolic names defined by the class can be resolved. A way of doing this is to include a first association between the obfuscated symbolic names and encrypted forms of the corresponding symbolic names in the program and to make a second association between the encrypted forms of the corresponding symbolic names and information used to resolve the symbolic names defined in the class. The loader then uses the first and second associations to resolve the obfuscated names.The class extension techniques may be combined with obfuscation of names defined in the program and static watermarking to provide layered protection of the mobile code. The obfuscation and definition of the first association are done prior to execution of the program and the class extension is done on execution of the program. The disclosed techniques are particularly well-adapted for use with the byte codes produced by Java language compilers from Java language programs.
REFERENCES:
patent: 4764959 (1988-08-01), Watanabe et al.
patent: 5287407 (1994-02-01), Holmes
patent: 5287408 (1994-02-01), Samson
patent: 5530752 (1996-06-01), Rubin
patent: 5559884 (1996-09-01), Davidson et al.
patent: 5613004 (1997-03-01), Copperman et al.
patent: 5692047 (1997-11-01), McManis
patent: 5745569 (1998-04-01), Moskowitz et al.
patent: 5892899 (1999-04-01), Aucsmith et al.
patent: 6006328 (1999-12-01), Drake
patent: 6102966 (2000-08-01), Tyma
patent: 6591415 (2003-07-01), Torrubia-Saez
patent: 6668325 (2003-12-01), Collberg et al.
patent: WO 97/04394 (1997-02-01), None
patent: WO 99/01815 (1999-01-01), None
patent: WO 99/13613 (1999-03-01), None
patent: WO 00/72112 (2000-11-01), None
Low, D., ‘Java Control Flow Obfuscation’, Univ. of Auckland, Jun. 3, 1998, entire document, http://www.cs.auckland.ac.nz/research/theses/1998/low—douglas—thesis1998.pdf.
Collberg & Thomborson, “Software Watermarking: Models and Dynamic Embeddings”, Department of Computer Science The Univ. of Auckland, Private Bag 92019, Auckland, NZ.
Collberg, Thomborson & Low, “A Taxonomy of Obfuscating Transformations”, Technical Report #148, Department of Computer Science The Univ. of Auckland, Private 92019, Auckland NZ.
A, Monden, H. Ilda, K. Matsumoto, K. Inoue, and K. Torii, “A Practical Method for Watermarking Java Programs”, In compsac2000, pp. 194-195.
A Monden, H. Ilda, K. Matusmoto, K. Inoue, and K. Torii, “Watermarking Java Programs,” in Proc. 4th International Symposium on Future Software Technology (ISFST' 99), pp. 119-124.
Luo Chenghui
Zhao Jian
Baum Ronald
Fraunhofer Gesselschaft
Kincaid Kristine
Nelson Gordon E.
LandOfFree
Protecting mobile code against malicious hosts does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Protecting mobile code against malicious hosts, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Protecting mobile code against malicious hosts will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3914642