How can I securely check if a username is already taken?

Posted by Geo on Stack Overflow See other posts from Stack Overflow or by Geo
Published on 2010-05-29T14:34:25Z Indexed on 2010/05/29 14:42 UTC
Read the original article Hit count: 197

Filed under:

AJAX

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security

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web

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user-registration

I have a form where someone can create a new user. I'd like to add some AJAX to check if a username is taken, as soon as the input field loses focus. I'm not really sure how to go about this, as this could pave the way to bruteforce attack, since you could check for any username and see whether or not it exists. Any suggestions?

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