Beefy Boxes and Bandwidth Generously Provided by pair Networks
good chemistry is complicated,
and a little bit messy -LW
 
PerlMonks  

Re: Single use Only

by Amoe (Friar)
on Jan 02, 2002 at 19:40 UTC ( #135691=note: print w/ replies, xml ) Need Help??


in reply to Avoiding multiple voting

Everything said by the other monks is true. But you can come close to blocking one-session multi-submits by generating a random word or number in GD, and displaying it on the submittal page, then checking if the user wrote it right. See merlyn's WebTechniques column for an example of this. ("Keep robots from stuffing your forms", I think)

However, this relies on people's laziness, which is generally a good bet, but may not be applicable sometimes :) Certainly amongst Perl programmers though...


--
my one true love


Comment on Re: Single use Only
Download Code
Re: Re: Single use Only
by jodrell (Acolyte) on Jan 02, 2002 at 20:58 UTC
    No technique is truly secure. Lycos introduced a "one time code" system on their SMS service to prevent automated robots spamming their service by creating a unique number in a GD-created image. Last I heard, someone had created a script that did OCR to read the number out...

    --
    jodrell.uk.net

Log In?
Username:
Password:

What's my password?
Create A New User
Node Status?
node history
Node Type: note [id://135691]
help
Chatterbox?
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others examining the Monastery: (7)
As of 2014-12-19 06:58 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?

    Is guessing a good strategy for surviving in the IT business?





    Results (72 votes), past polls