[All Versions] Safari cookies decryption

hey everyone
i forgot my password for one of my accounts and retrieving it is such a pain in the ass..
luckily i still am logged in from my iphone and still can access the site using my username and password..

i was going thru the backup of the cookies of my iphone and found the username and url of the site including an ecrypted string which i guess is my password..
i will share it with u guys hopefully someone will have the knowledge to decrypt it for me plz..

this is it:
%3A507368397%3AxZI8vDiHGLLco4yK

can anyone figure what it is plz

bump anyone!!!

The string is probably separated by the : character.

http://javascript:window.alert(unescape('%3A507368397%3Ax ZI8vDiHGLLco4yK')); in

will show you:

:507368397:xZI8vDiHGLLco4yK

the first part might be your (bank :-)account number or a checksum, the latter the password you will have to decrypt.

alright any way to decrypt!..
i mean any known algorithm for the cookies?
and ya u're right the first part is my account!