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 gr...

Obfuscation can be a simple tool for soft- ware protection. In this paper we present a method of machine code obfuscation, which can be applied to most present processors. The obfuscation method is based on a theory, which led to two useful theorems. The proposed algorithm of obfuscation was implemented and tested using analytical and empirical approaches. The obtained results give the first estimation of the maximum possible eciency of the obfuscation process.

The problem of protecting digital content -- software, video, documents, music, etc. -- from illegal redistribution by an authorized user, is the focus of considerable industrial and academic effort. In the absence of special-purpose tamperproof hardware, the problem has no cryptographically secure solution: once a legitimate user has purchased the content, the user, by definition, has access to the material and can therefore capture it and redistribute it. A number of techniques have been suggested or are currently employed to make redistribution either inconvenient or traceable. In this paper we introduce digital signets, a new technique for protecting digital content from illegal redistribution. The work motivates the study of the previously unexamined class of incompressible functions, analysis of which adds a cryptographic twist to communication complexity. 1 Introduction The problem of protecting mass-distributed digital content, such as software, audio, video, and digital libr...

In this paper, we present a new method to protect software against illegal acts of hacking. The key idea is to add a mechanism of self-modifying codes to the original program, so that the original program becomes hard to be analyzed. In the binary program obtained by the proposed method, the original code fragments we want to protect are camouflaged by dummy instructions. Then, the binary program autonomously restores the original code fragments within a certain period of execution, by replacing the dummy instructions with the original ones. Since the dummy instructions are completely different from the original ones, code hacking fails if the dummy instructions are read as they are. Moreover, the dummy instructions are scattered over the program, therefore, they are hard to be identified. As a result, the proposed method helps to construct highly invulnerable software without special hardware. 1

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 semantics preserving transformations such as code 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 dynam...

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.

Introduction Serious study of cryptography is highly mathematical and whole books have been written on this subject. We present here an overview of the aspects of interest for systems security. A good book for details is [Sta99], but Pfleeger and [Sum97] also have good discussions. A comprehensive book is [Sch96]. A two-part survey that discusses general aspects is [Cal00]. Value Cryptography is a valuable mechanism that can be used to provide: . Authentication---Can authenticate the identity of users, transactions, and systems. . Protection of messages---Can protect the secrecy of a message and prevent illegal modification. Cannot protect against destruction of the message. . Protection of software and data---Can protect the confidentiality of them although not avoid their destruction. For example, passwords can be encrypted. . Digital signatures---Can authenticate the origin of a message.<F

Recently, Java has been spread widely. However, Java has a problem that an attacker can reconstruct Java source codes from Java classfiles. Therefore many techniques for protecting Java software have been proposed, but, quantitive security evaluations are not fully given. This paper proposes an obfuscation scheme for Java source codes by destructing the encapsulation. In addition, we propose an evaluation scheme on the number of accesses to the fields and the methods of the other classes. We try to realize tamper-resistant software with the certain quantitive basis of security using our evaluation.

Abstract: In the world of computers a trusted object is a collection of possibly-sensitive data and programs that can be allowed to reside and execute on a computer, even on an adversary’s machine. Beyond the scope of one computer we believe that network-based agents in high-consequence and highly reliable applications will depend on this approach, and that the basis for such objects is what we call “faithful execution.” 1