Capcha verification with sound

PHP programming forum. Ask questions or help people concerning PHP code. Don't understand a function? Need help implementing a class? Don't understand a class? Here is where to ask. Remember to do your homework!

Moderator: General Moderators

Post Reply
User avatar
bokehman
Forum Regular
Posts: 509
Joined: Wed May 11, 2005 2:33 am
Location: Alicante (Spain)

Capcha verification with sound

Post by bokehman »

I am trying to produce a CAPCHA script with audio back up. I will record the letters and numbers into individual audio files and then join the files dynamically. For example if the code was: a1bDTg34 I want to join those sound bites together and send them to the client. What file format would you recommend and how would I join them using PHP.
User avatar
feyd
Neighborhood Spidermoddy
Posts: 31559
Joined: Mon Mar 29, 2004 3:24 pm
Location: Bothell, Washington, USA

Post by feyd »

pcm-wav or aiff or mp3. I've pick one of the first two over the latter. wav is probably the most universal and natively playable.
User avatar
bokehman
Forum Regular
Posts: 509
Joined: Wed May 11, 2005 2:33 am
Location: Alicante (Spain)

Post by bokehman »

Thanks! I've got something together now that stiches .WAVs.
Roja
Tutorials Group
Posts: 2692
Joined: Sun Jan 04, 2004 10:30 pm

Post by Roja »

Another suggestion is reduce the size.. realistically, on THESE forums (extremely active), we have 17,000 members. A unique captcha for each using letters and numbers [0-9A-Z] would only take 4 characters. I use 6 characters for confirmation codes in most of my applications, and simply use hex [0-9A-F], which gives me over a million unique captcha's. Once a user is signed up, you can reuse the captcha's, and making it any longer makes it very challenging for real users.

Of course, all but the most complex captcha's have already been defeated by automated software, so their value is debatable. ( http://sam.zoy.org/pwntcha/ ).
User avatar
bokehman
Forum Regular
Posts: 509
Joined: Wed May 11, 2005 2:33 am
Location: Alicante (Spain)

Post by bokehman »

Thanks for the advice. I have trimmed it back to four characters. Here's the script. What do you think?
Post Reply