Abstract: Systems and methods are disclosed for embedding information in software and/or other electronic content such that the information is difficult for an unauthorized party to detect, remove, insert, forge, and/or corrupt. The embedded information can be used to protect electronic content by identifying the content's source, thus enabling unauthorized copies or derivatives to be reliably traced, and thus facilitating effective legal recourse by the content owner. Systems and methods are also disclosed for protecting, detecting, removing, and decoding information embedded in electronic content, and for using the embedded information to protect software or other media from unauthorized analysis, attack, and/or modification.

Abstract: Systems and methods are disclosed for protecting a computer program from unauthorized analysis and modification. Obfuscation transformations can be applied to the computer program's local structure, control graph, and/or data structure to render the program more difficult to understand and/or modify. Tamper-resistance mechanisms can be incorporated into the computer program to detect attempts to tamper with the program's operation. Once an attempt to tamper with the computer program is detected, the computer program reports it to an external agent, ceases normal operation, and/or reverses any modifications made by the attempted tampering. The computer program can also be watermarked to facilitate identification of its owner. The obfuscation, tamper-resistance, and watermarking transformations can be applied to the computer program's source code, object code, or executable image.

Abstract: Systems and methods are disclosed for embedding information in software and/or other electronic content such that the information is difficult for an unauthorized party to detect, remove, insert, forge, and/or corrupt. The embedded information can be used to protect electronic content by identifying the content's source, thus enabling unauthorized copies or derivatives to be reliably traced, and thus facilitating effective legal recourse by the content owner. Systems and methods are also disclosed for protecting, detecting, removing, and decoding information embedded in electronic content, and for using the embedded information to protect software or other media from unauthorized analysis, attack, and/or modification.

Abstract: In a computerized method, a computer program is analyzed while the program is interpreted. The program is expressed in a first memory as input values and functions. Some of the input values are complex values which can have a plurality of component values. Each function operates on combinations of the input values and the functions of the program. The program is interpreted in a processor connected to the first memory. The processor is also connected to a second memory to store result values produced during the interpretation. Selected input values, components of the complex values, and functions are named only if the selected values, components, and functions are necessary to produce a selected result value. For each function of the program, the function which is interpreted, the input values on which the function depends, and the result value produced by the function during interpretation, are recorded in the second memory to dynamically perform a precise dependency analysis of the program.

Abstract: A data processor has provision for error recovery by the division of a program into a set of program blocks. The apparatus has a main store and a cache store that preserves the states that have previously been taken up by items of information prior to commencing each block so that the states of the items of information prevailing at the beginning of a block can be restored if required.