Re: Cryptography .. How to ?

From: Nick Gilbert (news@remove-this-bit.nickgilbert.com)
Date: 01/21/03 

From: "Nick Gilbert" <news@remove-this-bit.nickgilbert.com>
Date: Tue, 21 Jan 2003 14:59:14 -0000

> Does anyone has any idea how do i get back ( decrypt ) the data which is
> encrypted using MD5 encryption.

You can't do this. MD5 is a one way hashing algorithm. In fact, being
'one-way' is the entire point of MD5 :)

Typical usage would be:
An MD5 hash of a password would be stored in a database.
When a user logs in, the password they entered would be hashed using MD5 and
compared with the MD5 hash already in the database. If they're the same,
then the user entered the correct password. Any phrase will always hash to
the same output every time, and no two inputs will generate the same output.
This way, you can be sure the user knows the correct password, without the
insecurity of leaving the password itself lying around on the system it is
designed to be used for! The advantage of this approach is that only the
user knows the password. Even the database administrator has no way to find
out what the users password is. If they forget - they'd have to have their
password set to a new one manually.

If you want two way encryption, you'll have to look into other ways of doing
it using either private (symmetric), or public key encryption (asymmetric).
Which one you choose depends on your application.

Nick...

"Badal Kotecha" <badal_k@hotmail.com> wrote in message
news:eFsejTzqCHA.456@TK2MSFTNGP09...
> Hi All !
> Does anyone has any idea how do i get back ( decrypt ) the data which is
> encrypted using MD5 encryption.
>
> If you have any sample please send it.
>
> Thanks and regards
> Badal
>
>
>

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