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Decryption of text excrypted using md5() and crypt() tags





toughtrio
Is there a way do decrypt any passwords or a text probably that has been encrypted using the md5 or crypt tags or fuctions in php and stored in a database field.

Help needed urgently.

Warm Regards,
hexkid
toughtrio wrote:
Is there a way do decrypt any passwords or a text probably that has been encrypted using the md5 or crypt tags or fuctions in php and stored in a database field.


What would be the use of md5() or crypt() if it were possible?
Thankfully it isn't possible/practical.

If you know certain limits of the original text you might be able to get it, with, for example:
Code:
<?php
$encrypted = 'c23fa9996925b610710d93e28c59a3e2';
for ($c1=65; $c1<91; ++$c1) {
  for ($c2=65; $c2<91; ++$c2) {
    $attempt = chr($c1) . chr($c2);
    if (md5($attempt) == $encrypted) {
      echo 'Found! The original text was: ', $attempt;
      exit(0);
    }
  }
}
echo 'Sorry, unable to find original text.';
?>
AftershockVibe
No - the whole point of md5() is that it is irreversible.

The only way to get back the orginal information is via brute force, like the above script but that will probably time out for anything longer than 3 characters.

You can get a variety of brute force cracking programs, mostly written in C. It takes ages though. For example you can easily expect a lowercase only alphanumeric password which is 7 characters long taking a week to crack.
toughtrio
But seriously dont you all think that if we know by what method or a series of the methods of calculations the PHP script performs with the internal ALU, we may be able to decrypt it.

WHO MADE PHP ANYWAYS Wink , he might surely know whats the main procedure behind it.

Warm Regards,
hexkid
toughtrio wrote:
But seriously dont you all think that if we know by what method or a series of the methods of calculations the PHP script performs with the internal ALU, we may be able to decrypt it.

Anybody can know the calculation methods of MD5, SHA, RSA, DES, etc.
Maryndor
Quote:
Help needed urgently.

Hahaa! Laughing I'm very curious why it's so urgently??? Sounds like "I would like to crack something.". Smile Clever boy!

It IS possible. It IS very tough/hard/time-need/resource-need/luck-need/etc job. It IS something like "understand how big is the universe" (or something - Einstein).

I can give you a lot of ideas, examples, resources but will give you just one advice: Don't try it! Wink


Quote:
But seriously dont you all think that if we know by what method or a series of the methods of calculations the PHP script performs with the internal ALU, we may be able to decrypt it.


Personally I did a crypt method long time ago. Believe me it's ireversable. MD5 is same kind. But with the "components" that I've wrote above, you can decrypt it. Smile
DanielXP
http://md5encryption.com/
yjwong
Some hashes cannot be found though. These MD5 decryption sites rely on dictionaries which are limited, and therefore not reliable.
Maryndor
DanielXP wrote:
http://md5encryption.com/


LOL I've tried 5 times with 5 different words .. and surprise:

Quote:
Sorry, we could not find a matching decryption.


Laughing

But do you know what's the biggest affair in that website?! Everyone which encrypt a word is saved in db, then if you copy/paste the hash it's "decrypted" perfectly! I'm sorry... that isn't decription. As the author of the post above said: limited (or no?!) dictionary. My advice is , don't use such websites to get a hash. Razz

Quote:
91d12c2f88bf8197d092f85ddd9c0cbd
Rhysige
The best website for MD5 "decryption" I have found is one that claims this.
The latest iteration of the database has the following character set:

* 1-5 Length: a-z, A-Z, 0-9, !@#
* 6-7 Length: a-z, 0-9
* 8-10 Length: 0-9

And is 416Gb, with approximately 98 billion rows.
exarkun
It seems to be wrong. Using a hash calculator to convert a 9 digit word gives E272C66B18AFA6C69100A78B09E44FDE, which doesn't tally to at all.
Philip
i think there's no way to decrypt md5
since it's one way hash encryption..
and when encrypt a plain text to chipper text, there;'s already lost information from plain text that won't be ever recovered. and although that
there's many plain text that have a same chipper text. Wink


kv
toughtrio wrote:
But seriously dont you all think that if we know by what method or a series of the methods of calculations the PHP script performs with the internal ALU, we may be able to decrypt it.

WHO MADE PHP ANYWAYS Wink , he might surely know whats the main procedure behind it.

Warm Regards,


md5 or any hash algorithms have nothing to do with php as such. It is based on mathematical calculations. The series of steps followed to generate md5 hash is irreversible, even if you know the steps. A simple example, if you have a result of mathematical operation "sum", that is you know the answer of addition of several numbers, the fact that you know the operation doesn't help you to either derive the number of operands added or the value of individual operands.
toughtrio
But then in the example 'kv' gave, it could be possible to have two words having the same hash, and that is not the case with MD5. I understand that brute-forcing stuff, but then what would you do with like more than around 40 to 50 characters. Might take an year or more than that, even with a supercomputer guessing that hash.

Thanx everyone for helping, I went through this topic while searching for my posts on frihost, and found this one with replies I hadn't even seen before.

How amazing, posting on a topic started by myself, like

Code:
 <begin topic with toughtrio>
 <other amazing posts>
 <end topic with toughtrio>

Razz
Warm Regards,
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