Is it possible?

[vbPoet]

I am curious about reversing md5 32 bit hashes...
But is it possible ?

[visualAd]

No ...

[wossname]

I am curious about reversing md5 32 bit hashes...
But is it possible ?

Sure it is. If you have a military budget and about 1000000000000 years

[vbPoet]

No i have nothing like that
But what's the reason for that big NO ?
Could you please provide me some logic behind it ?

[visualAd]

If you want to reverse the encryption, you'll need to use reversable encryption. PHP's mcrypt extension provides this functionality. I suggest you take some time to familiarise yourself with the ciphers and example code in the documentation before you embark though.

[wossname]

MD5 is a 1-way algorithm. Meaning that it is impractical to even attempt to reverse the process, due to the enoumous numbers involved.

Also, there are an infinite number of messages for any known Message Digest string. So unless you already know th length of the original message you are royally screwed.

If you manage to pull this off then you will be a VERY rich person indeed.

[vbPoet]

Meaning that it is impractical to even attempt to reverse the process, due to the enoumous numbers involved.

Also, there are an infinite number of messages for any known Message Digest string. So unless you already know th length of the original message you are royally screwed.

Could you please explain it bit more because i want to know the technical reason of impracticality of reversing it in some detail.
Thank You

[wossname]

Well think about it. You start out with a 10 megabyte message and the MD5 string is only a few bytes long. How on earth do you intend to reconstitute the mesage from that? It can't be done, simply because you are throwing all the data away after subtly using it to alter the Message Digest in a loop. Every byte of the message affects each single bit of the digest. Thus if you change a SINGLE byte in the original message then the WHOLE digest is ruined and completely different.

You must have noticed how the digest is always the same length despite the size of the message. this could only be done if you actually deliberately destroy the original.

You'll need to google for further info. But believe me you aren't the first person to try this and you won't be the last. Cryptography is cool isn't it

Also look up the SHA1 algorithm (federal standard fo message integrity assurance).

The sexiest thing about this is that th MD is harmless. It does your enemies no good to know it and its only useful to YOU and your friends

imho, SHA1 is better than MD5.

[wossname]

by the way, SHA stands for Secure Hash Standard (Algorithm).