Wikipedia:Reference desk/Archives/Computing/2006 November 1

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November 1

VPN & Security

If I'm connected to a Public WiFi network, and I want to make a credit card purchase, am I more secure when connected to my school's VPN service or not?

It depends on two questions. Is the WiFi an encrypted connection? Is the VPN an encrypted connection? If you answers are:

no.no. You are not more secure - but the site should be using SSL (https site) - so there is some security.

no.yes: You are more secure. While the WiFi is not encrypted, the data being sent over it is.

yes.no: You are not more secure. The data sent on the WiFi is the same either way.

yes.yes: You are marginally more secure. Anyone that could hack the WiFi in real time can hack the VPN in real time.

All in all, credit card purchases online are more secure than giving your number to a stranger on the phone or to a stranger at some convenience store. There are some bad sites that steal data, but most purchase order are passed from computer to computer and never seen by a human. --Kainaw ^(talk) 02:25, 1 November 2006 (UTC)

Off the subject a bit but still related... During the holidays I pick up extra cash working for a local company taking gift orders. I'll usually have 2-3 people over the course of one holiday season that tell me during the casual conversation of the phone call that they are calling in their order instead of using the 'net because they don't want their CC# stolen or some such thing. Meanwhile, I could be writing every card number and expiration date down as they tell them to me. If I were to pull up an internet order though, I can only see the last four digits of the card number. The rest of the digits are never seen by human eyes. Dismas|^(talk) 08:44, 1 November 2006 (UTC)

You should ALWAYS be relying on SSL encryption when passing sensitive data across the internet. This ensures that ONLY your PC and the system you are sending the information to are privy to it. WiFi encryption or a VPN are both completely ineffective as a security means unless the system you are connecting to is within the network involved (i.e. on the Wireless network or within the confines of the VPN). SSL is used to protect data crossing the internet at large where many third parties have access to the raw data, so encryption on the browser/server connection is critical to protecting your information. --Jmeden2000 15:01, 1 November 2006 (UTC)

How to fix a microwaved iPod Mini.

Don't ask why -- but is there a way to fix an iPod Mini that was microwaved?

I'm really curious and want to know but won't ask why... That being said, what's wrong with it? What is it doing or not doing? Have you tried a reset? Do a google search for "iPod reset" and one of the first results should be the Apple page with reset instructions. If it's the same as the 4G full size iPods, all you have to do is hold down the top and bottom of the click wheel until it reboots, as far as I can remember. Dismas|^(talk) 10:41, 1 November 2006 (UTC)

The screen is cracked, and nothing displays on it. It doesn't appear to turn on, no charging symbol appears when it is plugged in, and there's no soft white noise when you plug in the headphones (there is on my working iPod). When plugged into a PC, there is a faint noise, of what I assume to be the hard drive spinning.

My completely uninformed opinion is that it's probably dead. OTOH remarkably, it's a very common occurrence. This site has a person who tried it and fried his iPod. This article says microwaves and delicate electronics don't mix. Here's someone who fried their iPod in the microwave in 5 seconds. Here's advice to put the iPod in the micro for 10 seconds in order to break it so that it can be exchanged for a new one. Aaaaand... Here's more evidence that it takes only 10 seconds to completely ruin an iPod with a microwave. I guess I wasn't much help, but it was interesting looking. Anchoress 11:09, 1 November 2006 (UTC)

You know why I think this is so common? Someone posted to a bulletin board asking how to completely but invisibly break his scratched iPod so that it could be returned, and was advised to microwave it. I bet the meme that's taken hold is that you can microwave an iPod in order to fix it. Anchoress 11:13, 1 November 2006 (UTC)

Is that "fix" as in "I'll fix you !" or having a dog "fixed" ? I suspect a jealous girlfriend is involved, myself. StuRat 18:25, 1 November 2006 (UTC)

Wow! This really gave me a good laugh. Who would fry in iPod?

Slow Processor

I have a couple of questions regarding my laptop I bought recently. It's a DELL Inspiron 6400,with Intel Core Duo Mobile Processor T2300E (1.66GHz/667MHz/2 X 1MB L2 Cache). 1GB Shared Dual Channel DDR2 SDRAM at 533MHz, 2 Dimm and a 60GB 5400rpm SATA Hard Drive.I didnt get a dedicated graphics card but it has the Intel Graphics Media Accelerator 950.

Firstly,I was promised improved processing capabilities with the Core Duo Processor.I was told I'd be able to do a virus-scan on my system and easily surf the net simultaneously,or rip music CD's while working on my sysytem.That is certainly not the case .It is as slow as my Pentium 4 processor desktop(512 MB RAM).What's the deal with that? A friend told me I had made a mistake in buying the Core Duo,I should have waited for the Core 2 Duo.The Core Duo was just a testing series. Is he right?

Secondly,can I increase the RAM of my laptop easily?Is it even possible?

Thirdly,I want Bluetooth capability on my system,but I didn't order it.Is there any way I can Bluetooth on my laptop now?

And lastly,can I play any kind of 3-D games on my laptop at all?I'm not talking about the high-end stuff like Doom 3 and/or FEAR.I mean gmes like FIFA 2006 and GTA Vice City.A friend(the same one)told me I could dedicate some of my RAM for gaming?Is that possible?If it is,what steps do I need to take?

Thanks in advance,I really need some help.

The core duo is an excellent processor, core 2 has only like a 10% performance gain- you have a low-end model though. RAM, make sure you get the right kind but yes. You might be able to play vice city if you dedicate more video memory through your graphics drivers --froth

It's true that the core duo is a good processor, you might want to check out that your's isn't dammaged. You can play those games, but all budget laps have pretty bad graphics cards, so the graphics won't be great. About Blutooth, I believe you can ge a USB Bluetooth interface, but I'm not sure where from or for what price. Englishnerd 17:36, 1 November 2006 (UTC)

Playing games is one of the most taxing activities on a computer. Some high end games may not work well without a dedicated gfx card, regardless of cpu power or ram speed and size. I myself bought my Dell Inspirion 9300 laptop with 557 DDR2 512MB 2xSODIMM (also has an ATI X300) I bought a 1xSODIMM 557 DDR2 1GB stick to replace one, hoping i could get 1.25GB of ram, but it wouldn't work with the originals. You may have to purchase upgraded RAM from Dell (at nearly 300% markup) if you want it to work with your original RAM. Otherwise, I recommend just buying 2xSODIMM 1GB sticks from http://www.newegg.com/ --Russoc4 17:43, 1 November 2006 (UTC)

Firstly, the software has to take advantage of having two processors. If it doesn't know the second processor is there, it won't use it.

Secondly, ATI Mobility Radeons have a HyperMemory thing where you can indeed dedicate system RAM to the video card. This is probably accessed through your ATI driver.

I don't have an ATI Mobility card.I have the Intel GMA 950,and I would like to know what games it is likely to support.

Software

What do you think is the coolest piece of free Windows software? --86.7.146.92 15:27, 1 November 2006 (UTC)

If it is "Windows", then that restricts it to the operating systems, really... But I like Windows 98SE for its relative lack of bloatware, and Windows XP because it is useful. x42bn6 Talk 17:22, 1 November 2006 (UTC)

LOL @ "bloatware". However, I think they are asking about free software that runs on Windows, not Windows software itself. StuRat 18:13, 1 November 2006 (UTC)

Oh, that makes more sense. To me, it would be a program like 3D Studio Max, but I quite like Mozilla Firefox. And, bloatware has its own article.  :) x42bn6 Talk 20:02, 2 November 2006 (UTC)

PuTTY, or virtualpc/qemu :) --froth^{T C} 03:26, 2 November 2006 (UTC)

websites

I am writing a class paper. Am I right in saying that Hyperlinks, through a web browser, allows one to jump from one web page to another within a website and also from one web site to another website? —The preceding unsigned comment was added by 72.66.41.31 (talk • contribs) .

Yes. Not only that, but hyperlinks can jump to different protocols and start up email programs when you click a mailto: link. See hyperlink. x42bn6 Talk 17:20, 1 November 2006 (UTC)

Future emulators of today's systems

More or less all of us have been there. We want to play that old game, but does Vista:b or XP accept it? Nuh-oh. We have to go somewhere else with games like, say, Flight Simulator 3. The search for an old computer with MS 95 is difficult indeed, but there are more difficult tasks to some.

I actually had a question. It can be phrased long or short, and here is the short one: Is there any system which exists today that attempts to act as an emulator for more or less every pre-MS XP game there has been? Okay, it could've been shorter, and it could have had a comma, but there you go.

I live in fear that when I reach the age of 60, I can no longer play Railroad Tycoon II. I can't NOW! Thanks in advance. 81.93.102.49 17:11, 1 November 2006 (UTC)

Well, Windows XP does come with built in support for legacy apps for DOS and Windows 9X. In practice, I've found that sometimes it will range simple(Duke Nukem 3D) to impossible(System Shock) to get old games working on it. As far as emulators goes there is DOSBox for DOS based games. As far as emulators for Win 3.1, Win16, and pre DirectX games I'm not sure of, but WindowsXP should be able to handle and Windows games that are built on DirectX. —Mitaphane _talk 18:05, 1 November 2006 (UTC)

You could run games under a virtual machine. Splintercellguy 06:30, 3 November 2006 (UTC)

Outlook emails on 2 PCs

I have Outlook on 2 PCs to deal with my emails, calendar and tasks. Is there any way I can have the two synconized? I know I can do it with a PDA, but what about syncing 2 PCs. Basically, I want it so they all have the same emails in the inbox and sent items folder and the same calendar, regardless of which PC received the emails and which made any changes. Many thanks, --86.139.127.29 17:33, 1 November 2006 (UTC)

With that program (Outlook), I doubt that is possible. This is because your mails are stored locally, that means on your computer. Access like you talk of would demand the mails to be on the internet. www.gmail.com should along with other online mail clients offer this kind of availability, and in my opinion, Gmail is a rather good email client. However, you risk what you always risk when something is online, plus I don't know how easy it is to download mails to your computer, so you may browse them all while being offline. I hope this helps. 81.93.102.49 17:39, 1 November 2006 (UTC)

That's not quite correct. There are mail programs that allow you to synchronize two locations periodically, by copying changes from each database into the other, so long as the two mail databases are connected at that time. For example, Lotus Notes has a "replicate" function which can do that. It's rather messy and complicated, however, so I wouldn't actually recommend such an approach. StuRat 18:07, 1 November 2006 (UTC)

You can do it with calendar and tasks, and I think you can do it with your email by setting it up so that when you check for mail on one computer it doesn't clear the server. The downside is you'd have to check them fairly closely in time proximity to each other, so that you didn't miss some emails. Another option is just to do everything on one computer and just copy the .pst file to the other one. Anchoress 18:20, 1 November 2006 (UTC)

Not quite the simple approach I was hoping for! --86.139.127.29 18:47, 1 November 2006 (UTC)

creating a disambig category

I am trying to create a "Disambiguation" category; the disambig page uses a template which includes the "Category: Disambiguation" text. It seems to work in the English version but not in the Danish version. I've looked at the two versions and they seem identical, except the language. Am I missing something?

• http://en.chainki.org/index.php?title=Cookbooks_(disambiguation)
• http://da.chainki.org/index.php?title=Kultur_(disambiguation)

Thanks for any ideas.

80.200.199.55 17:55, 1 November 2006 (UTC)

The obvious diff is the use of %28 and %29 in place of parentheses. Try changing that. StuRat 18:02, 1 November 2006 (UTC)

It's a difference, but I tried changing that and, No, it's not that (I've changed it above to make it clear that this is not the difference). See the difference between:

• http://en.chainki.org/index.php?title=Category:Disambiguation
• http://da.chainki.org/index.php?title=Kategori:Disambiguation

On the English pages, the "Category: Disambiguation" at the bottom of each page correctly adds the page to the category, but not in the case of the Danish version. Can anybody see the problem?

80.200.199.55 20:13, 1 November 2006 (UTC)

From what I could tell playing with it, it seems like "[[Category:Disambiguation]]" placed directly in an article works, but invoked indirectly with "{{Disambig}}" doesn't. So something about template inclusion might be messing up. Also, I note that the Kategori:Disambiguation has an entry for the template Skabelon:Disambig, but it apparently shouldn't because the Skabelon has the "[[Category:Disambiguation]]" under "<includeonly>". It's as if the "includeonly" had its sense inverted. You might try removing the "includeonly". -R. S. Shaw 08:14, 4 November 2006 (UTC)

Creating a Zip Job

Hello, I just downloaded WinZip 10.0 to my computer. It is the trial version. Now I know how to unzip a file that has been compressed, but I am not sure how to compress a document. When I went to create job I went through the process but at the end it said error. What or how can I create or compress a file and more then one?

right click the file and click "add to <filename>.zip" and tadaaa ! you got that file zipped on that same location !Muhammad Hamza 21:10, 1 November 2006 (UTC)

Also, you might look at Info-Zip, which is a libre/open source zip program. Superm401 - Talk 21:14, 1 November 2006 (UTC)

Is it possible to link (using the hyperlink feature) a page in a word document with another page in the same document?

I have a word document with 3 pages. Can I jump to the 2nd page by clicking on a word in the 1st page?

Yeah, there are a bunch of ways of doing it. Cross-referencing is one, turning on the Headings navigator bar is another, creating a table of contents is another. Anchoress 20:42, 1 November 2006 (UTC)

Sure. That's how the Table of Contents works in Word. User:Zoe|(talk) 02:52, 2 November 2006 (UTC)

Yes. When creating a hyperlink, just select "Place in this document". You usually have to create a bookmark first where you want the link to go. --Bennybp 04:10, 3 November 2006 (UTC)

Shared Folders Permissions

I want to share for only for some specific people on my network. i dont want others to be able to access those folders. i tried windows own shared folder permssions but failed to do so. We have a serial network (thats what people call it). It a network in which bunch of people are connected through NWay Switches using CAT5 cables. and we dont have any server coz we dont need one, so is the permissions thingy possible?Muhammad Hamza 20:58, 1 November 2006 (UTC)

Are you running XP Professional on all of them? If so, you should be able to do this easily. See "How to Share and Set Permissions for Folders and Files Using Windows XP". Superm401 - Talk 21:11, 1 November 2006 (UTC)

Digital Signatures

Perhaps this should be on Mathematics, but it was a tough call. How does the signing part of a digital signature work? Note that I am referring to signing, not encryption. Every explanation of this just says that the hash is encrypted with the sender's private key or that the sender performs a calculation with the has and their private key. Apparently, the recipient then decrypts the hash (or performs more math) with the sender's public key. However, private keys are used for decryption when the sender has encrypted with the associated public key. How then does the process work in reverse for signatures? Superm401 - Talk 21:07, 1 November 2006 (UTC)

In the case of RSA (using the same notation as in that artcle - public key $(e,n)$ and private key $(d,n)$, where $ed\equiv 1{\pmod {\phi (n)}}$) the encryption function is $c=p^{e}{\pmod {n}}$ and decryption is $p=c^{d}{\pmod {n}}$. While decryption can be done faster when the factorisation of $n$ is known, the two operations are essentially the same and the security lies in the difficulty of calculating $d$ without knowing the factorisation of $n$. So, to generate a signature $s$ of a message $m$, we can calculate $s=h(m)^{d}{\pmod {n}}$ (i.e. encypting a hash of the message with the private key) and the recipient can verify the signature by calculating $x=s^{e}{\pmod {n}}$ and $h(m)$ and checking whether $x=h(m)$. This relies on the fact that the keys are just numbers, there is nothing that requires the public key to be used as an encryption key and the private key to be used for decryption. -- AJR | Talk 12:50, 2 November 2006 (UTC)

In slightly simpler terminology, this is what happens: first, you calculate a hash of the message (it needs to be a one way hash). This step is not strictly necessary, you can simply sign the whole damn message instead of the hash of the message, but there isn't really a point to that, and this saves a bunch of space. Then you encrypt the hash using the private key instead of the public key. That signs the message. Why does this work? Read on. Now, the RSA encryption algorithm works in two directions. You can encrypt a message with a users public key, and thus only the holder of the private key can decrypt it. But you can also do it in the other direction; if you have the private key, you can encrypt it and everyone else can decrypt it. What is the point of encrypting something if everyone can decrypt it? This is the crucial point: only the holder of the private key can encrypt it in this way. Anyone can verify that it is indeed encrypted using a private key, but only 1 person can actually encrypt it. That way, if I have your public key and you send me a message that you have signed with your private key, I can be sure that it is you that is sending it because only you could possibly do that. Get it? Oskar 17:25, 4 November 2006 (UTC)