Software Analysis and Forensic Engineering » software plagiarism

The Software IP Detective’s Handbook

Bob Zeidman — Mon, 02 May 2011 14:23:04 +0000

My book on software intellectual property, a labor of love (and hate) for the last two years, has just been published by Prentice-Hall. The book is intended for several different audiences including computer scientists, computer programmers, business managers, lawyers, engineering consultants, expert witnesses, and high-tech entrepreneurs. Some chapters give easy-to-understand explanations of intellectual property concepts including copyrights, patents, and trade secrets. Other chapters are highly mathematical treatments describing quantitative ways of comparing and measuring software and software IP. The first chapter of the book outlines which chapters are most important for the different audiences.

Overall the book covers the following topics:

Key concepts of software intellectual property
Comparing and correlating source code for signs of theft or infringement
Uncovering signs of copying in object code when source code is inaccessible
Tracking malware and third-party code in applications
Using software clean rooms to avoid IP infringement
Understanding IP issues associated with patents, open source, and DMCA

You can purchase your copy from Amazon.com here.

Zynga and CrowdStar, copying or coincidence?

Bob Zeidman — Mon, 03 Jan 2011 03:33:40 +0000

Software Analysis & Forensic Engineering Corporation today released a case study of Online IP Screening between Zynga’s FarmVille game and CrowdStar’s Happy Aquarium game. The study shows some interesting correlation between the source code for the two games. SAFE Corporation is officially announcing its SAFE Online IP Screening service that is targeted at social games and other online applications. The screening service is a subscription service to regularly examine online applications for signs of copying. In this first case study, we already found surprising results. Even after the normal process of eliminating correlation due to third party code, commonly used identifier names, automatically generated code, common algorithms, and common authors, correlation remained. Was this intentional? Illegal? Acceptable? Coincidence? Decide for yourself: see summaries of this and other case studies here and register to download the full case studies here.

One unique feature of online applications is that often the full source code is downloaded to the user’s machine. This makes it easier for your competitors to copy your code. It also makes it easier for us to detect that copying. Learn more about SAFE Online IP Screening here or email us for details about how we can protect you from unauthorized copying and dissemination of your code.

SAFE introduces CodeSuite-LT

Bob Zeidman — Mon, 03 Jan 2011 03:27:12 +0000

CodeSuite-LT® is a less expensive, limited version of the full CodeSuite tool. Each tool in the suite produces a readable report that can be used to find copying. CodeSuite-LT includes BitMatch, CodeCross, CodeDiff, CodeMatch, FileCount, and FileIsolate. It also includes the ability to filter results using SourceDetective. CodeSuite-LT does not produce a database and does not allow post-process filtering of results. Instead, it generates an easy-to-read report that can be used to pinpoint copying.

Which is Right For You?

Which product is right for you, CodeSuite or CodeSuite-LT? Click here for a table that compares the features of both programs so you can choose the right solution.

Words to fear: I’m from the government and I’m here to help

Bob Zeidman — Tue, 02 Nov 2010 07:13:04 +0000

So the government is finding ways to fix the patent system. One of those fixes is the Peer-to-Patent program. It seems like a good idea. In order to speed up the granting of good patents and quickly eliminate the bad ones, allow people from everywhere and anywhere to submit prior art. If that’s actually the way it worked, I’d celebrate; it would be a great resource for finding prior art and making the patent office more efficient. Unfortunately my experience is that the program creates more problems than it fixes. The patent office invited me to participate in the program. Two people posted “invalidating prior art” for my patent application entitled “Detecting Plagiarism in Computer Source Code.” This art was related to my invention, but definitely was not invalidating. Here is the first independent claim of my original patent application:

A computer-implemented method comprising:
- creating, by a computer system, a first array of lines of functional program code from a first program source code file, the first program source code file including the lines of functional program code of a first program and lines of nonfunctional comments of the first program;
- creating, by the computer system, a second array of lines of nonfunctional comments from a second program source code file, the second program source code file including lines of functional program code of a second program and the lines of nonfunctional comments of the second program;
- comparing, by the computer system, the lines of functional program code from the first array with the lines of nonfunctional comments from the second array to find similar lines;
- calculating, by the computer system, a similarity number based on the similar lines; and presenting to a user an indication of copying of the first program source code file wherein said indication of copying is defined by the similarity number.

Here is the only dependent claim of the prior art patent US 7,568,109:

A system for comparing at least a first corpus to a second corpus, comprising:
- an analyzer identifying concepts in the corpuses, said analyzer determining a frequency rating of each of said concepts in each corpus;
- for each corpus, replacing each instance of each of said concepts with its respective determined frequency rating to create a frequency file;
- and a comparator comparing the frequency file for the first corpus to the frequency file for the second corpus, wherein said comparing the frequency file for the first corpus to the frequency file for the second corpus further comprises comparing portions of one corpus against the other corpus.

The second prior art submission was simply a reference to the UNIX diff command. While the diff command is relevant, it is a simple line-by line comparison of text files without any understanding or parsing of programming source code. It doesn’t separate functional lines of code (statements) from nonfunctional lines (comments).

Judging by their remarks, the posters to the Peer-to-Patent site didn’t understand patents, and didn’t read the patent claims. They should be allowed to post references, but the ultimate decision must be in the hands of those trained in examining patents. However, the patent examiner told me that her supervisor didn’t want to issue a patent that had been publicly noted to be invalid, and so after months of arguments I had to arbitrarily narrow the claims to get allowance, resulting in patent US 7,823,127. So now, anyone from anywhere with any ulterior motive (particularly those who believe no software should be patentable) can bring about the quick rejection of an otherwise useful and valid patent.

SAFE Corporation announces CodeScreener online software plagiarism detection

Bob Zeidman — Wed, 06 Oct 2010 23:46:28 +0000

CodeScreener: Online Plagiarism Detection for Software

SAFE Corporation has developed an online plagiarism detection service for software. The CodeScreener™ service is built on SAFE Corporation’s court-tested CodeSuite® forensic software and patented source code correlation technology. CodeScreener is designed to streamline the plagiarism detection process, giving you a thorough analysis of each file and a consistent set of correlation metrics. It’s online, it’s interactive, and it’s much less expensive than standalone CodeSuite. Contact our Sales Department to get a free evaluation license.

Multiprocessing CodeSuite-MP

Bob Zeidman — Wed, 01 Sep 2010 23:54:05 +0000

Until now there were two ways of running really big jobs of CodeSuite. One was to simply run it and wait for as long as it took. Really large jobs can take as much as a week or two. The other option was to run the job on CodeGrid, our framework that distributes the job over a grid of networked computers. CodeGrid shows an almost linear speedup for each computer on the grid, but it requires someone to maintain the computers and the network and that can be a daunting job. Now there’s a third option;, CodeSuite-MP allows you to run multiple jobs on a single multicore computer. We’re seeing a near-linear speedup for the number of cores, and there’s no special maintenance required. We’re even seeing a near-linear speedup using virtual cores. If you want to get a license for CodeSuite-MP, contact our sales department.

Can whitespace patterns provide clues to plagiarism?

Bob Zeidman — Wed, 02 Jun 2010 03:11:57 +0000

Over the years I’ve run into expert witnesses and attorneys who have told me about software copyright infringement cases where the only clues that copying occurred were patterns of spaces and tabs (“whitespace”). The idea is that if a truly ambitious thief wanted to cover his tracks, he would modify the stolen code so much that there was no longer a visible trace of copying. However, the clever software sleuth could find patterns of whitespace that the thief had missed; although virtually nothing remained, the invisible tabs and spaces could produce a conviction.

This always sounded intriguing, but I wondered whether anyone had ever tested this theory. We could find no articles or papers on the subject, except for one inconclusive paper, and I dreaded to think that some programmer was convicted based on an untested theory. I decided to have my consulting company, Zeidman Consulting, do some carefully controlled research. If the results turned out well, SAFE Corporation would add whitespace pattern algorithms to CodeSuite to further enhance its ability to detect copying.

Our results were published in a paper entitled Measuring Whitespace Patterns as an Indication of Plagiarism that was recently presented at the ADFSL Conference on Digital Forensics, Security and Law. Our results are summarized in the final paragraph:

This whitespace pattern matching method can be used to focus a search for evidence of similarity or copying, but this method cannot stand by itself.

What we discovered is that even very different files have often have similar whitespace patterns. At Zeidman Consulting we’ve used whitespace patterns to confirm copying that was already detected through the use of CodeMatch to find correlated programming elements. In those cases, the whitespace patterns offered further confidence in our findings and in some cases showed which program had been developed first. For a copy of the paper, email us at info@SAFE-corp.biz.

Our next research project is to look at sequences of whitespace within files. Maybe there we’ll find some clues to copying. But for now our results show that whitespace patterns without any other evidence should not be used to determine that copying occurred.

DUPE: Depository of Universal Plagiarism Examples

Bob Zeidman — Fri, 02 Apr 2010 05:32:40 +0000

In 2003 I created the CodeMatch program that very quickly became a de facto standard in software IP litigation. I created a test bench of purposely plagiarized code that could be used to independently and objectively compare the results produced by different plagiarism detection programs. Some in the academic community claimed that my tests were biased toward the algorithms used by CodeMatch, which explained why CodeMatch fared so well compared to the other programs. However, these same critics, despite my requests, never produced their own set of standard tests.

Although I believe that the standard tests I have used are not biased, it occurred to me that there could be a better way to eliminate even unintentional bias. The solution would be to take the source code for certain open source programs and announce a new open source project that would involve purposely plagiarizing the code. Programmers from around the world would be invited, perhaps in a competition, to change the source code while retaining the functionality. The original programs and the plagiarized versions submitted from others would be stored in a database known as the Depository of Universal Plagiarism Examples or DUPE. Plagiarism detection programs would then be run on DUPE and comparisons of the results could be made to determine which programs best detected copying. Also, important statistics about plagiarized code could be determined, as well as patterns identified in order to improve the plagiarism detection programs.

SAFE Corporation has begun looking into creating this database. However, we realize that we would like to work with partners in academia and industry. We believe that there are several key issues that need to be resolved in creating DUPE. These are:

Choosing appropriate open source projects.
Creating a minimum definition of software plagiarism.
Creating the database.
Determining policies including who can access it, how it will be used, and who will maintain it.
Determining how to run the tests, how to generate the results, and how to distribute the results.

Please contact me if you’re interested in working on this important and groundbreaking project.

Interesting software IP cases of 2009

Bob Zeidman — Fri, 01 Jan 2010 20:52:02 +0000

Here is my list of the most interesting software IP cases of 2009,
in chronological order:

What to look for in an expert?

Bob Zeidman — Fri, 01 Jan 2010 20:48:52 +0000

I recently came across a study in the Journal of the American Academy of Psychiatry and Law out of the The University of Alabama entitled “Credibility in the Courtroom: How Likeable Should an Expert Witness Be?” To be honest, I’m not sure I understand their conclusion:

The likeability of the expert witnesses was found to be significantly related to the jurors’ perception of their trustworthiness, but not to their displays of confidence or knowledge or to the mock jurors’ sentencing decisions.

Reading the paper doesn’t make it a whole lot clearer for me, and I think their mock trial setup is a bit contrived, particularly since the jury consisted of psychology students, a demographic that you’d be unlikely to find on a real jury. Also there were only two expert witnesses for the comparison. To their credit, they discuss these potential shortcomings. I do think, however, that the paper points out something (that may have already been obvious)—there is more to being an expert witness than just being correct. Personality and presentation are strong factors.

On the other hand, I feel that this subjective aspect should be minimized. Experts need standards and measurable quantities whenever possible. Before I began developing the concept of source code correlation, the way software copyright infringement and trade secret theft cases were resolved was to have two experts give contrary opinions based on their years of experience. The judge or jury would tend to get lost in the technical details, a strategy purposely employed by some experts and attorneys, and a judgment would depend on which expert appeared more credible.

Instead, I decided to expand the field of software forensics and made it my goal to bring as much credibility to the field as DNA analysis, another very complex process that is well accepted in modern courts. I still believe that an expert’s credibility and likeability will always be factors in IP litigation, but that the emergence of source code correlation and object code correlation provide standard measures that bring a great deal of objectivity to a lawsuit’s outcome.