was thinking and searching about this topic all day I am just curious, If you know whats the best way to crypt information and still be able to decrypt them later own safely Please let me know And wouldn't other people be able to decrypt data just like I did ?

What you need to consider is this, if you can decrypt a password then its not secure, if someone tries hard enough then he will crack it.
Here is a link that will help you find the answer to your question
stackoverflow.com/questions/1289061/best-way-to-use-php-to-encrypt-and-decrypt

I Think The Best Way to crypt information and still be able to decrypt them later own safely is not to use md5 is it's crackable,using sha1 it's 128 bit and the devices able to crack is at leat of $1,000,000 of price and not everybody has it.Understnd what i meant??