Computer/IP that was originally used to write a matlab code

I am a MATLAB course instructor and I've caught a weird case in a submitted matlab file for an exam which I guess someone other than my student has written it! Is there a way to check the properties of a matlab file and see what computer and/or IP was used to write/create that file?

[John D'Errico]

An m-file is just a text file. There would be no stamp that shows the origin. I'd do an online search for some of the code fragments that would seem obviously not written by the student. My guess is you will find the code either in an Answer from here, or on the file exchange, or possibly on StackOverFlow. While we strongly encourage people not to answer obvious test and homework questions, some people still do so.

[Cyrus Rezvanifar]

I personally designed all the questions with novel ideas and also in a way that would use the characters of the student's first name! There is absolutely no way that this solution already exists online!

[Jan]

@Cyrus: The solution would exist online, if she has posted it in a public forum.

[Star Strider]

If you suspect that your student posted it here, you can contact MathWorks with all the identifying information you have (email, etc.) and see if they can track down and recover posts (including deleted posts) from that person, and any associated replies.

MathWorks can reinstate deleted posts, so they do have copies.

[Jan]

@Star Strider: You find most of the deleted posts in Google's cache also. But I do not think, that it is relevant, if she has posted the question here and deleted it afterwards. This is not forbidden and does not allow to draw any conclusions. Only a copy of the solution written by someone else would be an evidence.

Although I do not like homework cheating, I really hope that TMW would not reveal any personal information in such a case. And I hope that Cyrus would not share personal information of one of his students with MathWorks. While cheating is against the rules and can have serious consequences, it is not criminal, but violating the data protection and personal rights is. (Sorry, "criminal" is most likely the wrong word. I mean: breaking the laws of the state compared to rules of the university.)

[Jan]

@John D'Errico: There are Chinese, French and German Matlab forums also. I got homework questions over LinkedIn and ResearchGate also. See https://www.mathworks.com/matlabcentral/answers/1822-foreign-matlab-forums.

[Fatemeh Salehikhoo]

I am an instructor too and I have the same problem.

I am also teaching SolidWorks. SolidWorks archive all the details, time, author, computer name, etc of a creation.

It is very easy to who is chatting.

I don't think Matlab has such a thing

[Walter Roberson]

.m files are strictly text.

.slx (Simulink) and .mlx files are not strictly text.

[Stephen23]

"I am also teaching SolidWorks. SolidWorks archive all the details, time, author, computer name, etc of a creation."

Solidworks imports and export into a variety of file formats:

https://www.spatial.com/resources/glossary/solid-works-file-format

some of which are text and some of which are binary format. In principal both could be altered after creation.

Answer 1

[Jan]

You are a MATLAB course instructor. We should expect, that you know the simple nature of text files like M-files. They contain only the characters you can read in the editor, neither IPs nor a history. ZIP files will not reveal further details like fingerprints also, but what do you expect? Why do you assume that an IP would help you? You still could not prove, who typed in the code on this computer. The "history" of a file would not tell you securely, who has written it. What you are asking for is neither possible for very basic technical reasons, nor would it help in any way. Therefore I find your question strange.

Of course we could ask the NSA, if they search in their Prism data base for all of her digital communication. Perhaps she has whatsupped a "thanks for solving my homework". But although, no, because this is technically possible, this would be a bad idea for ethical reasons. The total monitoring of persons is evil.

The only reliable and fair way is to ask the student, if she has written it, and to let her explain the code. If she cannot tell you the meaning of each line, the code is not from her. But if she can, she has either written it, or understood it deeply. Then she had solved in both ways, what the purpose of the homework was.

Cyrus, many person try to cheat here and all over the world. I'm glad to see, that almost all members of this forum encourage them to use homework to learn. Perhaps you find out, who has written the code, but this is rather unlikely. But what you can do for sure is to encourage her to learn. This is your job.

[EDITED] Sorry, I find this question such strange, that I want to ask you directly, with all respect: Are you really a teacher for IT? Or are you a student who plans to cheat and wants to find out if it is secure? In both cases the core of my answer is: encourage to learn.

[Fatemeh Salehikhoo]

Very disrespctful

[Jan]

@Fatemeh Salehikhoo: Think twice. A Matlab instructor does not know, that text files cannot contain hidden personal inforation? He does not mention, if M, MLX or SLX files are meant? This let me speculate, that the OP is not the teacher, but a student.

Even if he is the teacher, he asks for hidden personal information like the IP address. In democratic systems the official authorities like the police and prosecution can check the owner of an IP, but not teachers on the search of cheaters.

I'm working as instructor also. It is very easy to find out, if a person has written a code or not: Just ask for the purpose of one line. I've offered an exhaustive analysis of the code and suggested improvements, simplifications and accelerations, as I do here in the forum also. Many students respect this support and ask for assistence in other projects also. Cheating students kick themselves.

The question does not match my understanding of mutual respect.

[Walter Roberson]

Suppose you had a student with the somewhat unusual name "Protector", and you saw that the student's work had been editted by both "yortep" and "walter". Are they cheating?

Probably not.

The title "Protector of the people" (as in the person in charge of the defence of the tribe) was, in the days of the Germanic tribes, "Walter" or "Walther". Names get around; in Ukranian, this is Уолтер which might end up transliterated as Yortep . But students are often required to register by official name, and often to use an English form of the name, so bureaucracy might have required that they register according to the meaning of the name, (that is, "Protector") instead of according to its common English form, "Walter".

Okay, how about IP address?

Well, are we talking about internal IP address or external IP address? I have my 2.4 GHz internal network configured in the 172.16 to 172.31 private range (172.16/12), but I have my 5 GHz internal network configured in the 192.168 private range (192.168/16). I mostly work on the 5 GHz network, but there are a couple of weak spots in my living room where I may need to switch to 2.4 GHz (which carries better through solid obstacles.) On my desktop, to avoid potential IP address classes, my ethernet is in one IP address range and my WiFi is in a different IP address range.

Okay, how about external IP? I used to be on a DSL that was entitled by contract to change my external IP address every time I disconnected, and in practice changed my external IP every 60 days. Which is still the official policy of that company (the largest iSP in the city.) My house-mate routinely uses a VPN service that makes them appear to be in a different country (VPNs are recommended by Firefox, and by Google Chrome, and by our ISP.)

Answer 2

[Walter Roberson]

No information about that is retained for .m file (unless perhaps somehow it got saved in a resource fork on a Mac, which would not normally be the case.)

Sometimes you can get a hint from the creation date, especially if you had them zip the files together (.zip stores dates)

Simulink models just might contain a hint about the author; I am not sure either way.

.exe or .dll or .mex* would be the most likely to have had date information compiled in.

[Cyrus Rezvanifar]

They only had to submit .m files of their solutions. Besides, they had to submit the zipped file in a dropbox folder with closed access at the end of the exam session! My guess is she has sent a picture of the questions to a friend and has submitted the solution file received from him/her! That's why I'm trying to access the history of the file if possible.