homepage Welcome to WebmasterWorld Guest from
register, free tools, login, search, pro membership, help, library, announcements, recent posts, open posts,
Become a Pro Member
Home / Forums Index / Code, Content, and Presentation / PHP Server Side Scripting
Forum Library, Charter, Moderators: coopster & jatar k

PHP Server Side Scripting Forum

Preventing repeated users registration
Preventing repeated users registration

 4:48 pm on Jan 17, 2008 (gmt 0)

Hello everyone..

How can i prevent users to make several accounts on my website with php?

simply i want to make sure that from each computer only 1 account is created?

i tried IP nd cookies... but ppl will use proxies and delete their cookies.. and they will join again...




 5:41 pm on Jan 17, 2008 (gmt 0)

How are you storing your user account information?
As if this information is in a database then you can query the database to see if the user is already there.

Also why do you only want 1 account per PC? Surely you want 1 account per person, not 1 per computer.

Welcome along to WebmasterWorld.


 5:42 pm on Jan 17, 2008 (gmt 0)

Welcome to WebmasterWorld!

There are a few threads floating around on this issue. Here is one particular one that I was able to turn up: [webmasterworld.com...]

Basically it comes down to how much you really need to stop multiple registration, as it is something that is difficult to make foolproof.


 6:13 pm on Jan 17, 2008 (gmt 0)

Thx u for ur help....

well actually i want 1 account per person...

users with unique email/username can join and also im using activation emails....

also i store last login ip address of users in db....

but i notice recently some users use proxies!

i need to know if is there any other info i can get from users... like computer name or any other thing that help me know 2 account is for 1 person?

i read the other topic... but i cant really use "hammerin" and "link clicks" casue there are like 100 new registration daily and it takes time to check 'link clicks' and still u cant be sure about duplicated user...


 8:12 pm on Jan 17, 2008 (gmt 0)

users with unique email/username can join and also im using activation emails

How are you storing this information? As you should be able to query your information to see if the new registration has the same email address as a previous entry.

Also storing ip address is a little pointless, as there are a lot of people with dynamic IP addresses, AOL users all use proxies and these may be different proxies with each new request, people that register at work then go home with have a different ip address, etc.

You cant directly get the computer name or MAC address of the client.
You could always set a cookie...but these get deleted as you have already said.

I think that the easiest answer would be to query your user information at make sure that the email addresses are not duplicated.

[edited by: PHP_Chimp at 8:15 pm (utc) on Jan. 17, 2008]


 9:47 pm on Jan 17, 2008 (gmt 0)

sorry dude.... by this sentence:

users with unique email/username can join and also im using activation emails

i mean that if name@example.com join... no one else can join again with that email... plus im sending actication links to email so i verify email addresse...

but still some ppl make emails and join again...


is there any way that i can get MAC address or Computer Name through php or other program?


 9:55 pm on Jan 17, 2008 (gmt 0)

That sort of information is not something you can get through php, as php is a server side language. So doesnt directly interact with the client.

I dont think that you can get that information from javascript but someone else may know differently.

Could you not give people the option to look up there email address to see if they are already registered? As im guessing that if people are re-registering it is because they either dont use that email any more (allow them to update there account), they forgot there password (allow some way to get access back) or they didnt remember if they registered (allow them to give you there email address and you can look for them).


 10:12 pm on Jan 17, 2008 (gmt 0)

well most of them create accounts when i suspend their account because of not following the rules of the forums on the website...

also i noticed some cases that some ppl has made profiles similar to other profiles.. and post msg in forums as if they are someone else


 10:27 pm on Jan 17, 2008 (gmt 0)

i google for javascript code.

it works on IE after asking for permission but its not working on Mozilla

var ax = new ActiveXObject("WScript.Network");
document.write('User: ' + ax.UserName + '<br />');
document.write('Computer: ' + ax.ComputerName + '<br />');
catch (e)
document.write('Permission to access computer name is denied' + '<br />');

[edited by: coopster at 11:20 pm (utc) on Jan. 17, 2008]
[edit reason] removed url [/edit]


 4:22 pm on Jan 23, 2008 (gmt 0)

is there any way that i can get MAC address or Computer Name through php or other program?

Soory i think the answers NO

I dont think so as the MAC address changes as the packet traverses the interenet - I dont have my CCNA text books in the office to quote chaper and verse :-)


 6:28 pm on Jan 23, 2008 (gmt 0)

On XP, it's pretty easy to change your MAC address anyway...

Here's one idea: most people who create multiple accounts use the same password, when they register look for existing accounts with same password and if there's a match, especially with a suspended account, tell them that user registrations are now "subject to moderator approval", then compare their profile with the matched accounts and make a decision based on that. But don't tell them that their password matches another account's as this may give them a clue to hack into another legitimate user.

Global Options:
 top home search open messages active posts  

Home / Forums Index / Code, Content, and Presentation / PHP Server Side Scripting
rss feed

All trademarks and copyrights held by respective owners. Member comments are owned by the poster.
Home ¦ Free Tools ¦ Terms of Service ¦ Privacy Policy ¦ Report Problem ¦ About ¦ Library ¦ Newsletter
WebmasterWorld is a Developer Shed Community owned by Jim Boykin.
© Webmaster World 1996-2014 all rights reserved