Method and apparatus for securing executable programs against copying
a technology of executable programs and executable programs, applied in the direction of digital transmission, unauthorized memory use protection, instruments, etc., can solve the problems of unauthorized copying, software is easily copied, and cannot be readily copied in the general available form or in the form in which it is executed by the intended user,
Inactive Publication Date: 2008-06-24
RICOH KK
View PDF12 Cites 15 Cited by
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Benefits of technology
[0016]The security chip could also include a real-time clock, RC (resistor-capacitor) time constant circuit, or other dynamic logic circuit to confirm that the processor is executing instructions at an expected rate. This prevents a processor from being accelerated to speed up the process of running the program through all the possibilities needed to build an unauthorized branch table or from being slowed to perform hardware analysis.
[0017]Furthermore, because the security chip maintains the branch table, it can calculate what the next branch is, so that the processor only need provide the values neetled to evaluate whether to take a conditional branch. In order to handle return instructions, the security chip also maintains the program stack for the processor. This security feature prevents the processor from requesting unexpected branch information.
Problems solved by technology
The difficulty lies in the fact that software is easily copied and any copy protection or prevention scheme must allow for the eventual copying of portions of the software if it is to be executed.
Thus, for a program to be secure and still be useful to its intended user, the program cannot be readily copyable in its generally available form or in the form in which it is executed by the intended user.
However, where software needs no support or documentation and is used on systems where viruses cannot be transmitted, such as video game systems using video game cartridges with game software stored in read-only memory (ROM), unauthorized copying is still prevalent.
Thus, encryption of the program data alone does not provide real protection, since it must be decoded eventually to be used.
This particular problem, of course, extends to all forms of program storage media which are detachable, not just video game cartridges.
Many copy protection systems are a deterrent to casual copyists, but not to determined copyists, who might be willing to spend large sums of money and time to break a copy protection scheme in order to be able to manufacture large numbers of unauthorized copies of a program.
Therefore, when the goal is to stop large-scale and educated copyists, software-only protection is not viable.
If the authorization device is not present, the program refuses to continue or performs some other undesirable action.
These protection systems are open to two methods of attack, both of which could render the protection ineffective.
In a first type of attack, a copyist would analyze the circuitry of the hardware authorization device to determine its essential elements and from that information make duplicate, unauthorized authorization devices.
Therefore, what is needed is an apparatus which allows a processor to execute program code, over a possibly insecure bus, while requiring an impractical amount of work on the part of a copyist to reproduce the program data for use apart from the apparatus or to reproduce the apparatus.
Method used
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View moreImage
Smart Image Click on the blue labels to locate them in the text.
Smart ImageViewing Examples
Examples
Experimental program
Comparison scheme
Effect test
Embodiment Construction
[0029]FIG. 1 shows a common application for the present invention, namely video games. It should be apparent after reading this disclosure that the invention is not limited to video games or programs stored on cartridges. In FIG. 1, a game console 10 is shown with a game cartridge 12 about to be mated to game console 10 via a bus 14. We assume herein that a copyist is able to read the game program and game data as it is stored in game cartridge 12 and is also knows everything that goes on in game console 10. According to the preferred practice in the design of security devices, we also assume that the copyist knows all the derails of any security circuits and algorithms except for any keys or passwords. Because the primary goal of the system is to allow a legitimate user to run the program, it is impossible to prevent the copyist from determining the outcome and flow of the program by running it with a given set of input data. Thus, the goal of the security of this system is to requ...
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More PUM
Login to View More Abstract
A secure system for executing program code in an insecure environment while making it impossible, or at least impractical, to determine how to copy the program code and associated data is provided. A program memory contains encrypted program data and security circuitry contained within an integrated circuit is provided for decrypting the program data as it is needed by a processor. A portion of the processing steps which would be done by the processor in an insecure system is performed in this secure system within the secure circuitry using portions of the decrypted program data which are not provided to the processor. Program data is parsed it out based on a proper request to the security chip from the processor. A key value stored in volatile memory is used in the decrypting process and the volatile memory is positioned on the integrated circuit such that its contents are lost before a chip peel provides access to the volatile memory.
Description
BACKGROUND OF THE INVENTION[0001]The present invention relates to the field of securing executable programs against copying. More specifically, in one embodiment the invention provides security against copying in an open hardware system where access to the processor executing the program and the memory holding the program is assumed.[0002]Securing computer programs (software) against unauthorized copying has been a concern of software developers since software was sold as a separate product. The difficulty lies in the fact that software is easily copied and any copy protection or prevention scheme must allow for the eventual copying of portions of the software if it is to be executed. Unless the software is secured in a chip (integrated circuit) which also contains the microprocessor which will execute the software, the executed portions of the software must pass from the distribution media to the processor along circuit lines which are monitorable. Thus, for a program to be secure ...
Claims
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More Application Information
Patent Timeline
Login to View More IPC IPC(8): H04L9/00G06F1/00G06F21/00
CPCG06F21/123G06F2221/2107
InventorSCHWARTZ, EDWARD L.GORMISH, MICHAEL J.
OwnerRICOH KK