Re: Crypt Function-- Encryption and Decryption

Mulley, Nikhil wrote:

Hi Rens, Can you please be more specific or can you show some practical examples or procedural way ? Thanks, Nikhil --Smile Always , it costs nothing

    -----Original Message-----
    *From:* Rens Admiraal [mailto:mailinglists@etraned.nl]
    *Sent:* Sunday, November 21, 2004 8:52 PM
    *To:* jonepet@gmail.com
    *Cc:* Mulley, Nikhil; php-general@lists.php.net
    *Subject:* Re: [PHP] Crypt Function-- Encryption and Decryption

    What would be the use of a hash if it was easy to recover ?

    You can use it by storing the hash of a password, en when the user
    supplies you his password in a script, you hash it again... and
    compare those two hashes...
    Trying to recover the value from which the hash is the result is
    called cracking, and no programming!

    Jon-EIrik Pettersen wrote:

    Mulley, Nikhil wrote:

    Hi All,

    I have a password file , which has all the passwords words
    encrypted with the Crypt Function

    I know that Crypt uses one-way algorithm to generate the
    encryptions and PHP has no Decrypt function , ( but can it be
    developed to have one ?)

    But I am eager to know whether it is really impossible to
    decrypt the passwords , if possible , how it caqn be done. like
    salts and all

    Can somebody *please* throw more light on Crypt() and Encryption
    and Decryption in this thread.

    Thanks,

    Nikhil
     

As far as I know the standard crypto-methots used in crypt() is one-way-hashing. The data used when encrypting is lost, the encrypted data is generated using this data. There is no other methods to get these data back other than brute-forcing (guess, encrypt with the same algorithm and compare) but it may take months/years depending on the size of the orginal data.