[thelist] Preventing Malicious Login

[Anthony Ettinger]

>    1. What's the name of the image that is generated
> on some login
>       websites that make the user enter the numbers
> displayed within the
>       image into a text box?

"Visual confirmation" - so people don't script the
login process.

>    2. What it is about these images that make image
> reader software from
>       detecting what's written within the image?

It's inaccessible, because an image is in binary
format, and screen readers can't read the data. Stems
from the rule of "don't put content in images".

Some sites have an alternavite audio file that can be
played to read the numbers.

Anthony Ettinger
ph: (408) 656-2473
blog: http://www.chovy.com