[PEN-TEST] IE Cookie Crypt-Analysis - Good or Bad

["Ruso, Anthony" <aruso () POSITRON QC CA>]

Hi All,

        What are common methods used in decrypting/encrypting cookies. Would
many of you trust the use of cookies to store - lets say - passwords and
personal information. I'm trying to extract passwords from a clients website
through the use of cookies. They used to store website passwords in clear
text. I managed to convince them to encrypt them but how can I test their
encryption choice and methods. My crypt-analysis experience is very basic.
Any feedback would be greatly appreciated.

Thanks