Tag Archives: software plagiarism

Was the Microsoft Empire Built on Stolen Goods?

The history of the computer industry is filled with fascinating tales of sudden riches and lost opportunities. Take that of Ronald Wayne, who cofounded Apple Computer with Steve Wozniak and Steve Jobs but sold his shares for just US $2,300. And John Atanasoff, who proudly showed his digital computer design to John Mauchly who later codesigned the Eniac, typically recognized as the first electronic computer, without credit to Atanasoff. Perhaps the most famous story of missed fame and fortune is that of Gary Kildall. A pioneer in computer operating systems, Kildall started the company Digital Research and wrote Control Program for Microcomputers (CP/M), the operating system used on many of the early hobbyist personal computers, such as the MITS Altair 8800, the IMSAI 8080, and the Osborne 1, before IBM introduced its own PC. Kildall could have been the king of personal computer software, but instead that title went to his small-time rival Bill Gates. For years, rumors have circulated that the code for the original DOS operating system sold by Microsoft is actually copied from the CP/M operating system developed by Digital Research.

A couple years ago we took it upon ourselves to search out the original code and use CodeSuite to determine the truth once and for all. Our research was summarized in a popular (and not-so-popular) article in IEEE Spectrum entitled Did Bill Gates Steal the Heart of DOS? If you haven’t read it, you should. It’s a fun read but it only summarizes our exhaustive results using our tools and procedures for finding copied code. The article generated a lot of controversy and we always intended to publish the full technical details of our analysis, but it’s surprising how many people don’t like our conclusion and wouldn’t publish my paper. But now the full academic paper entitled A Code Correlation Comparison of the DOS and CP/M Operating Systems is available online in the Journal of Software Engineering and Applications. If you want to know the details, and you want to know the truth, it’s in the article and the details are in the paper.

S.A.F.E. Releases CodeSuite 4.7

Software Analysis and Forensic Engineering has just released a new version  of CodeSuite that has some really great new features.


PID  spreadsheets

What’s  a PID? It’s a partial identifier. Or more specifically, a partially matching identifier. That’s where two identifiers in code almost match. So for example, the identifiers identifier1 and confident_boy share the partial identifier (or “PID”) ident. CodeMatch has always been able to correlate PIDs and use that in calculating the identifier correlation score as a component of the entire correlation score between two source code files. But there can be so many PIDs that users got blurry-eyed trying to view them all and find suspicious ones in a CodeMatch HTML report. So we came up with a solution. You can now export the PIDs from a CodeSuite database into a spreadsheet. You can see not only the PIDs, but the original identifiers that share the PIDs. Now you can sort and select, cut and paste, and generally look for clues to copying in a simple spreadsheet.



Part of our process for finding copying has been to first find all the source code files in a directory of files so that you know what to examine. However, there are lots of source code files, and some can be missed. Some programming languages are a bit uncommon and you may not recognize the source code files. Well, we found a solution to that too. The new FileIdentify function of CodeSuite allows you to point at a folder and generate a spreadsheet containing all of the file extensions in that folder and all subfolders. If CodeSuite recognizes the (potential) programming language, it will put that information in the spreadsheet too.



From the beginning of CodeSuite, when there was only CodeMatch, the database has always been a fully documented text file that anyone can view. This allows our customers to make their own tools to extract data and statistics from a CodeSuite comparison, and some customers have created some very interesting utilities. Our database format was simple, but grew more complex over the years. Now we have a function in CodeSuite that converts any CodeSuite database into XML so that you can use off-the-shelf tools to examine it, translate it, or write utilities to extract data and statistics.

Be a Pioneer in the Field of Software Forensics

I hope you’re all aware of my book The Software IP Detective’s Handbook: Measurement, Comparison, and Infringement Detection. It’s the first book on Software Forensics, a field that I pioneered at Software Analysis and Forensic Engineering and Zeidman Consulting. Whereas Digital Forensics deals with bits and files, without any detailed knowledge of the meaning of the data, Software Forensics deals with analysis of software using detailed knowledge of its syntax and functionality to perform analysis to find stolen code and stolen trade secrets. The algorithms described in the book have been used in many court cases. The book also describes algorithms for measuring software evolution, particularly as it relates to IP changes.

If you are a teacher, this is a great time to incorporate the materials in the book into your courses on software development, intellectual property law, business management, and computer science. There’s something for everyone in the various chapters of the book. Your students and you will be at the forefront of an important and very new field of study.

If you’re interested, please contact me.

HTML Preprocessor Released

S.A.F.E. recently released the HTML Preprocessor. The HTML Preprocessor is designed to transform web pages into files that are amenable to analysis by CodeSuite, DocMate, and other source code analysis tools. The HTML Preprocessor examines HTML files and other markup language files and extracts all embedded code into separate files. These files each contain only one kind of code that can be easily analyzed and compared using CodeSuite and DocMate. The code contained in these generated files are:

  • Scripts such as JavaScript and VBScript
  • Cascading style sheets (CSS)
  • Comment text containing HTML comments
  • Message text containing HTML user messages
  • HTML tags
  • Pure HTML
  • Pseudocode representation of the HTML

CodeSuite 4.4 and CodeSuite-LT 1.2 Released

S.A.F.E. recently released version 4.4 of CodeSuite and version 1.1 of CodeSuite-LT. The most important new feature of this version is that these programs now recognizes many different text encoding formats including ASCII, UTF-8, UTF-16, and UTF-32. Characters in alphabets other than the Latin alphabet used for English are now supported. For example, code with comments or strings in Japanese, Korean, Chinese, or Russian can be compared correctly.

The most significant change is to BitMatch. When examining binary object code to find text strings, you can now specify the encoding format of the file. If you’re not sure about the encoding, you can choose multiple formats.

As demand for our products increase outside the United States, we realized a need to support languages in those countries also.

The Software IP Detective’s Handbook

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?

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

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

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:

  1. 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:

  1. 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

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.