Wikipedia:Reference desk/Archives/Computing/2015 September 20

= September 20 =

Open source calculator that looks like a real Texas Instruments calculator
What software calculator has the closest look-and-feel to a real hand calculator like a TI-83 or the TI-84? For a picture look at the TI-83 series. I know that there are better alternatives to perform calculations using a laptop. Sagemath is an example, among others. However, I am interested in getting used to the calculator allowed at many examination, not at the calculation result properly. --Scicurious (talk) 00:00, 20 September 2015 (UTC)


 * I have heard good things about Wabbitemu [ https://wabbit.codeplex.com/ ]. According tto this PDF page, it runs a downloaded image of the code that runs on the actual TI calculator, so everything should act the same, including any bugs (you don't want to discover that your calculator has a bug that your emulator doesn't while taking an important test!) A web search also turns up TilEm [ http://lpg.ticalc.org/prj_tilem/ ] and jsTIfied [ https://www.cemetech.net/projects/jstified/ ]. I tried Virtual TI a long time ago and was not impressed, but maybe there is a newer version that is better.


 * Please come back and update this with the results of your experiences with the above emulators so the next person can benefit from your experience. Thanks! --Guy Macon (talk) 01:36, 20 September 2015 (UTC)

Windows 10 - msconfig
In Windows 10, msconfig, General tab, I select the radio button for "normal startup", but it won't save it (even if I Apply or OK). It always goes back to "Selective startup", with a square in "Load system services", a check in "Load startup items", and a check in "use original boot configuration", the latter of which is disabled. Is this normal? Is it OK? Bubba73 You talkin' to me? 05:22, 20 September 2015 (UTC)


 * I just tried it and I'm experiencing the same behavior. Sounds like a bug.  Do these instructions help? www.ehow.com/how_7390089_repair-msconfig.html A Quest For Knowledge (talk) 14:59, 20 September 2015 (UTC)


 * For some strange reason, ehow.com is blacklisted, so I had to remove the http:// from the URL. A Quest For Knowledge (talk) 15:00, 20 September 2015 (UTC)


 * eHow is a low quality content farm which outsources writing to anyone and rewards those authors on the traffic they pull in - see MediaWiki talk:Spam-whitelist/Archives/2010/08. -- Finlay McWalterᚠTalk 15:33, 20 September 2015 (UTC)


 * Sure, if you're using it as a reliable source in article space. The filter should be smart enough to distinguish between article space and the Reference Desk.  A Quest For Knowledge (talk) 15:53, 20 September 2015 (UTC)


 * You can request a whitelisting for the RD if you want. I myself have occasionally used eHow, however it's something I avoid for reasons besides the blacklist. Anyway I think you're missing the point of the blacklisting which is to discourage spammers, no matter what part of RD they target. Whether spammers are likely to target the RD is hard to say. Nil Einne (talk) 16:21, 20 September 2015 (UTC)


 * Ammm, two humans I know who returned to 'Windows 7' because 'Windows 10' is not compatable with certain things. -- Space Ghost (talk) 18:26, 20 September 2015 (UTC)

Those instructions don't seem to address this problem (except I'm not sure if it is a problem, I haven't seen any ill effects). Bubba73 You talkin' to me? 05:22, 21 September 2015 (UTC) do a search on search engines using syntax "windows 10 msconfig" — Preceding unsigned comment added by 2A03:2880:3010:BFF6:FACE:B00C:0:1 (talk) 17:57, 22 September 2015 (UTC)

Am I making a hash of this idea?
This could be under Computing or Math. Computing wins (unless y'all don't agree).

I'm looking to host a collaborative project, where each user can choose to remain anonymous. However, I'd like to have a system whereby those who chose the anonymous route can later change their mind.

Let's take Wikipedia as an example. Anyone can anonymously add something or make a change, and there's no reasonable way to find out who they are.

If, in the future, an editor, for reasons of their own, decided to claim credit for a particular edit, there's no way for that editor to prove that they're the one who made that edit, if they were originally anonymous.

I've heard of trapdoor functions. I'm wondering if it's possible and/or reasonable to use these for this project.

My idea is that each time the user contributes, they include a whichamacallit (hash?), which is the product of two numbers. They keep those two numbers secret until such time as they wish to let people know that they were the contributor. My (limited) understanding of the trapdoors is that if they know the two numbers, that's almost incontrovertible proof that they are the perpetrator.

Is this idea feasible? Not having a lot of computer smarts, or knowing a whole lot of math, how would I implement this, without investing a lot of (or any) time or money for what I'm sure has been done.

Please keep in mind that I'm NOT suggesting that this is a good idea for Wikipedia. That's just an example that I feel more than a few readers are passingly familiar with.

Also, there's no need for super-security for my intended use. I'm not worried about a super-power breaking through the users identity.

Thanks for any help or ideas you might come up with. Bunthorne (talk) 21:40, 20 September 2015 (UTC)


 * Yes, user should submit a hash of their identity and contact information.
 * For example, in Linux I can type

khan@ToshiK:~$ echo 3dcaddy | md5sum 6a8d1f3d555c1ab285ec66854d15c4eb -
 * Reverting 6a8d1f3d555c1ab285ec66854d15c4eb to 3dcaddy is quite difficult.--3dcaddy (talk) 21:57, 20 September 2015 (UTC)


 * sorry to interject like this echo adds a newline by default, so your example isn't hashing the 7 ASCII character sequence "3dcaddy" but the 8 ASCII character sequence "3dcaddy\n". Use echo -n to suppress the newline, which yields the correct md5sum 5d1c09823512e0aee5080c5858968945 -- Finlay McWalterᚠTalk 14:50, 21 September 2015 (UTC)


 * Yes, that's right. The OP could also put everything in a file, and run "md5sum file".


 * Thanks for the quick response. I didn't realize it could be that easy.  Unfortunatly, I don't do Linux (although I realize I should).  Is there an easy way to do it with windoze? Bunthorne (talk) 22:06, 20 September 2015 (UTC)


 * Never mind. I did a quick search on "md5", and found a bunch of answers. Thanks for the tip. Bunthorne (talk) 00:32, 21 September 2015 (UTC)
 * I had marked this "resolved", but removed it since some of the responses brought up other questions. See below Bunthorne (talk) 20:23, 21 September 2015 (UTC)
 * One thing to bear in mind is that the high speed GPUs (edit: also ASICs, although only people with a specific goal in mind tend to have these) can compute certain hashes like MD5, combined with their popular usage to store passwords in some circumstances means that coming up with the reverse for a short string hash can actually be fairly trivial, even just an internet search. This didn't work with 3dcaddy (if we ignore this page), but would have worked with "bebopjazz1" (random example I came up with when searching for something) or "BillGates"  and yes, even Bunthorne  . If you get people to use a salt, you'd eliminate rainbow tables, unless people get interested enough in your website to develop a rainbow table for it (as I assume you'd need to use a fixed edit: known salt), but still won't eliminate the GPU problem.  If we assume most people are only going to be hashing their name or some pseudonym and most of these don't have numbers, and so only use upper and lower case letters and perhaps space and underscore, I suspect up to 11 characters may be feasible for someone without that much more resources than a dedicated gamer. ( is a little old and doesn't have exactly what you're looking for but is close.) It gets even worse if we decide it's most likely a real name from the Anglophone world or something of that sort. (Similarly if you're only using numbers, probably something like 18 decimal digits could be feasible.)  You'd generally want people to include at least 20 characters IMO and make sure it's more than just a name, maybe 30 or even 50 to be safe considering possible future advancements. An alternative (edit: or perhaps combined with a decent sized string) is to use a hash designed to be slower on GPUs edit: (and hopefully ASICs) like bcrypt or scrypt, although I'm not sure how well cryptologically tested these are.  Also due to the nature of hashes, people will have to record or remember exactly what their original string was including cases etc. Okay you could make a brute forcer for them, if they have a good idea of what it is, but that would complicate things somewhat. (Sufficient info would also reduce possible disputes if person A claims the hash represents them and person B who were the first to say it was them must have somehow reversed it.)  Nil Einne (talk) 07:38, 21 September 2015 (UTC)

Just as a historical note: in science there is always a conflict between wanting to publish an imporant new result in order to ensure you are recognized as being the one who discovered it, and wanting to investigate further in order to produce a more complete report. These days, as I understand it, scientists will first publish a short letter summarizing their finding and follow it later with a full paper. But centuries ago, what they did first in this situation was to publish an anagram of their result, and then when they were ready to do a full report, they would provide the explanation to the anagram. See anagram for examples. Of course if they were being tricky it was always possible that the same letters would anagram to more than one relevant sentence, saying different things! --174.88.134.156 (talk) 03:39, 21 September 2015 (UTC)


 * In the modern publish or perish environment of academics, it is very common to turn everything into multiple publications. For example, I had an idea that I thought was obvious. Everyone I spoke to said it was not obvious and apparently wrong. So, I implemented it and demonstrated that it worked. Then, I published a summary of the background information (summary papers are popular for textbook chapters). Then, I presented/published the general idea at a conference. Then, I published my findings. All together, the time between the summary paper and final publication was three years. So, I had three years to publish final findings while still demonstrating the work with the initial publication as a "guess what you can do with this knowledge" part of the summary paper. As an aside - I also take part in the "publish every paper as many times as possible" method of publication. For example, a paper on track management of hard drives became a paper on track management of radars, which became a paper on track management of cell towers. I'm now working on a paper for track management for a multi-signal bus in a cell processor system. 209.149.113.66 (talk) 11:50, 21 September 2015 (UTC)

It depends a little on how anonymous you want the edits to be. Using a hash of a secret (as proposed above) is fine if you want to know that one person made a set of edits, but not know who the person is. If you want stronger anonymity, where you don't know who made each edit, and can't tell which edits are made by the same person, then you need to include something unique into the hash. If this unique element is public, then it's still possible for the person to verify that they made that edit. For example, the content of the edit, or the time at which the edit was made could be added to the secret and then hashes (e.g. if I choose a secret of "Dave1", then a hash for this edit could be generated from the string "Dave1-10:40, 21 September 2015 (UTC)", and there would be no way of linking this to my next edit without knowing the secret). MChesterMC (talk) 10:40, 21 September 2015 (UTC)

Thanks for the great responses. As usual, the answers caused me to think of more questions.

Would making multiple hashes for the same data (with minor changes) make it easier to break the hash? For example, suppose I used the following inputs:

my email: foo@bar.com

My email: foo@bar.com

Contact foo@bar.com

foo@bar.com

Neglecting the fact that these are somewhat short, would using all of these at different times make it easier to extract the "foo@bar.com?.

How easy would it be to generate a different input to give the same output. This would be to enable "Plausible deniability" in the event that someone broke the hash, and tried to pin it on me when I don't want my identity known. Bunthorne (talk) 20:23, 21 September 2015 (UTC)


 * Yes. If you have a series of hashes, there is a higher chance that one of them could be reversed. But this is hard.
 * Finding a different input that reaches the same output is hard, but possible. md5sum is not completely safe against tailored attacks for people with sophisticated resources.
 * Still, just ask anyone to put name+email+some random text into a file and run "md5sum file." Let them generate different hashes with different random texts. That's pretty safe.--3dcaddy (talk) 00:10, 22 September 2015 (UTC)

Amazon ID
Does amazon (I use amazon.co.uk) have a unique id for each product? If so, how does one find out what it is and how does one enter it into the system to go to that item? -- SGBailey (talk) 23:35, 20 September 2015 (UTC)
 * Amazon Standard Identification Number. Vespine (talk) 01:57, 21 September 2015 (UTC)


 * If you go to the product page and scroll down to the box marked "additional information" you will see the ASIN. You can enter any ASIN in the Amazon search box to find any item.--Shantavira|feed me 07:52, 21 September 2015 (UTC)


 * Thanks. That is sort of what I expected. It appears that for books the ISBN number is the ASIN. Amazon's help says "You can search for an ISBN or an ASIN in our catalogue. If you know the ASIN or ISBN of the item you are looking for, simply type it into the search box (which can be found near the top of most pages), hit the Go button and, if the item is listed in our catalogue, it'll appear in your search results". So to test I copied B00P6JZ4UQ from a (uk) pair of shoes, went to the homepage, pasted it into the search bar and pressed the magnifying glass (presumably "search") (there is no "Go" button). And behold, I get "Your search "B00P6JZ4UQ" did not match any products". Is it them or me? -- SGBailey (talk) 21:52, 21 September 2015 (UTC)
 * Amazon doesn't find B00P6JZ4UQ for me either, but you can just use google, search for amazon B00P6JZ4UQ, that worked for me: http://www.amazon.co.uk/Clarks-Smart-Huckley-Spring-Leather/dp/B00P6JZ4UQ Vespine (talk) 22:49, 21 September 2015 (UTC)