PROBLEM TO BE SOLVED: To solve the problem, wherein it is impossible for an electronic content information provider to provide commercially secure and effective method, for a configurable general-purpose electronic commercial transaction/distribution control system. SOLUTION: In this system, having at least one protected processing environment for safely controlling at least one portion of decoding of digital information, a secure content distribution method comprises a process for encapsulating digital information in one or more digital containers; a process for encrypting at least a portion of digital information; a process for associating at least partially secure control information for managing interactions with encrypted digital information and/or digital container; a process for delivering one or more digital containers to a digital information user; and a process for using a protected processing environment, for safely controlling at least a portion of the decoding of the digital information. COPYRIGHT: (C)2006,JPO&NCIPI

https://apps.dtic.mil/dtic/tr/fulltext/u2/a423264.pdf

Systems and Methods for Secure Transaction Management and Electronic Rights Protection

This paper describes a new replication algorithm that is able to tolerate Byzantine faults. We believe that Byzantinefault-tolerant algorithms will be increasingly important in the future because malicious attacks and software errors are increasingly common and can cause faulty nodes to exhibit arbitrary behavior. Whereas previous algorithms assumed a synchronous system or were too slow to be used in practice, the algorithm described in this paper is practical: it works in asynchronous environments like the Internet and incorporates several important optimizations that improve the response time of previous algorithms by more than an order of magnitude. We implemented a Byzantine-fault-tolerant NFS service using our algorithm and measured its performance. The results show that our service is only 3% slower than a standard unreplicated NFS.

/pdf/practical-byzantine-fault-tolerance-58gb0de0hd.pdf

Practical Byzantine fault tolerance

Digital watermarking is a key ingredient to copyright protection. It provides a solution to illegal copying of digital material and has many other useful applications such as broadcast monitoring and the recording of electronic transactions. Now, for the first time, there is a book that focuses exclusively on this exciting technology. Digital Watermarking covers the crucial research findings in the field: it explains the principles underlying digital watermarking technologies, describes the requirements that have given rise to them, and discusses the diverse ends to which these technologies are being applied. As a result, additional groundwork is laid for future developments in this field, helping the reader understand and anticipate new approaches and applications.

Digital Watermarking

From the Publisher:
Steganography, a means by which two or more parties may communicate using "invisible" or "subliminal" communication, and watermarking, a means of hiding copyright data in images, are becoming necessary components of commercial multimedia applications that are subject to illegal use. This new book is the first comprehensive survey of steganography and watermarking and their application to modern communications and multimedia. 

Handbook of Information Hiding: Steganography and Watermarking helps you understand steganography, the history of this previously neglected element of cryptography, the hurdles of international law on strong cryptographic techniques, a description of possible applications, and a survey of the methods you can use to hide information in modern media. Included in this discussion is an overview of "steganalysis," methods which can be used to break steganographic communication.

This comprehensive resource also includes an introduction to and survey of watermarking methods, and discusses this method's similarities and differences to steganography. You gain a working knowledge of watermarking's pros and cons, and you learn the legal implications of watermarking and copyright issues on the Internet.

Information Hiding Techniques for Steganography and Digital Watermarking

Informally, an obfuscator O is an (efficient, probabilistic) "compiler" that takes as input a program (or circuit) P and produces a new program O(P) that has the same functionality as P yet is "unintelligible" in some sense. Obfuscators, if they exist, would have a wide variety of cryptographic and complexity-theoretic applications, ranging from software protection to homomorphic encryption to complexity-theoretic analogues of Rice's theorem. Most of these applications are based on an interpretation of the "unintelligibility" condition in obfuscation as meaning that O(P) is a "virtual black box," in the sense that anything one can efficiently compute given O(P), one could also efficiently compute given oracle access to P.

In this work, we initiate a theoretical investigation of obfuscation. Our main result is that, even under very weak formalizations of the above intuition, obfuscation is impossible. We prove this by constructing a family of functions F that are inherently unobfuscatable in the following sense: there is a property π : F → {0, 1} such that (a) given any program that computes a function f ∈ F, the value π(f) can be efficiently computed, yet (b) given oracle access to a (randomly selected) function f ∈ F, no efficient algorithm can compute π(f) much better than random guessing. We extend our impossibility result in a number of ways, including even obfuscators that (a) are not necessarily computable in polynomial time, (b) only approximately preserve the functionality, and (c) only need to work for very restricted models of computation (TC0). We also rule out several potential applications of obfuscators, by constructing "unobfuscatable" signature schemes, encryption schemes, and pseudorandom function families.

/pdf/on-the-im-possibility-of-obfuscating-programs-3jhukv9d43.pdf

On the (Im)possibility of Obfuscating Programs

It has become more and more common to distribute software in forms that retain most or all of the information present in the original source code. An important example is Java bytecode. Since such codes are easy to decompile, they increase the risk of malicious reverse engineering attacks. In this paper we review several techniques for technical protection of software secrets. We will argue that automatic code obfuscation is currently the most viable method for preventing reverse engineering. We then describe the design of a code obfuscator, a tool which converts a program into an equivalent one that is more diicult to understand and reverse engineer. The obfuscator is based on the application of code transformations, in many cases similar to those used by compiler optimizers. We describe a large number of such transformations, classify them, and evaluate them with respect to their potency (To what degree is a human reader confused?), resilience (How well are automatic deobfuscation attacks resisted?), and cost (How much overhead is added to the application?). We nally discuss some possible deobfuscation techniques (such as program slicing) and possible countermeasures an obfuscator could employ against them.

A Taxonomy of Obfuscating Transformations

We identify three types of attack on the intellectual property contained in software and three corresponding technical defenses. A defense against reverse engineering is obfuscation, a process that renders software unintelligible but still functional. A defense against software piracy is watermarking, a process that makes it possible to determine the origin of software. A defense against tampering is tamper-proofing, so that unauthorized modifications to software (for example, to remove a watermark) will result in nonfunctional code. We briefly survey the available technology for each type of defense.

/pdf/watermarking-tamper-proofing-and-obfuscation-tools-for-16ph8wfveb.pdf

Watermarking, tamper-proofing, and obfuscation - tools for software protection

It has become common to distribute software in forms that are isomorphic to the original source code. An important example is Java bytecode. Since such codes are easy to decompile, they increase the risk of malicious reverse engineering attacks.In this paper we describe the design of a Java code obfuscator, a tool which - through the application of code transformations - converts a Java program into an equivalent one that is more difficult to reverse engineer.We describe a number of transformations which obfuscate control-flow. Transformations are evaluated with respect to potency (To what degree is a human reader confused?), resilience (How well are automatic deobfuscation attacks resisted?), cost (How much time/space overhead is added?), and stealth (How well does obfuscated code blend in with the original code?).The resilience of many control-altering transformations rely on the resilience of opaque predicates. These are boolean valued expressions whose values are known to the obfuscator but difficult to determine for an automatic deobfuscator. We show how to construct resilient, cheap, and stealthy opaque predicates based on the intractability of certain static analysis problems such as alias analysis.

/pdf/manufacturing-cheap-resilient-and-stealthy-opaque-constructs-4go7umdyde.pdf

Manufacturing cheap, resilient, and stealthy opaque constructs

The present invention provides obfuscation techniques for enhancing software security. In one embodiment, a method for obfuscation techniques for enhancing software security includes selecting a subset of code (e.g., compiled source code of an application) to obfuscate, and obfuscating the selected subset of the code. The obfuscating includes applying an obfuscating transformation to the selected subset of the code. The transformed code can be weakly equivalent to the untransformed code. The applied transformation can be selected based on a desired level of security (e.g., resistance to reverse engineering). The applied transformation can include a control transformation that can be creating using opaque constructs, which can be constructed using aliasing and concurrency techniques. Accordingly, the code can be obfuscated for enhanced software security based on a desired level of obfuscation (e.g., based on a desired potency, resilience, and cost).

Obfuscation techniques for enhancing software security

Watermarking embeds a secret message into a cover message. In media watermarking the secret is usually a copyright notice and the cover a digital image. Watermarking an object discourages intellectual property theft, or when such theft has occurred, allows us to prove ownership.The Software Watermarking problem can be described as follows. Embed a structure W into a program P such that: W can be reliably located and extracted from P even after P has been subjected to code transformations such as translation, optimization and obfuscation; W is stealthy; W has a high data rate; embedding W into P does not adversely affect the performance of P; and W has a mathematical property that allows us to argue that its presence in P is the result of deliberate actions.In the first part of the paper we construct an informal taxonomy of software watermarking techniques. In the second part we formalize these results. Finally, we propose a new software watermarking technique in which a dynamic graphic watermark is stored in the execution state of a program.

/pdf/software-watermarking-models-and-dynamic-embeddings-1j1pt9gwox.pdf

Clark Thomborson

Papers

A Taxonomy of Obfuscating Transformations

Watermarking, tamper-proofing, and obfuscation - tools for software protection

Manufacturing cheap, resilient, and stealthy opaque constructs

Obfuscation techniques for enhancing software security

Software watermarking: models and dynamic embeddings