[urbanwks]

i understand that md5 was built to generate one-way hashing of files[and is misused by most as a security measure, since a dictionary attack is more than possible, and usually easy].

but my question is:
since the md5 hashing is in absolutely no way random, why can't it be possible to somehow reverse the algorithm?

or maybe i'm missing something or thinking too much again.

[BlazingWolf]

There has to be a way since like you said it is in no way random. There just isn't a decryption algorithm out there for md5.

[winblowz]

Think about what blazing wolf said.... also
Ok try to think of it like this.

Even if you understood how an md5 hash worked--you still would not be able to decrypt it. The process is said to be irreversible. (although thats what they said about the Vigenere encryption so long ago)

Mathematically, it is said to be irreversible. however, it would seem logical enough that if a program can be made to encrypt a document using a certain method, then a program could be used to find characters, or conduct neccesary calculations to reverse those methods, and decrypt the document.

NOT with an md5- I really have no idea how an md5 actually works, but I do know that all attempts to decrypt an md5 protected document have been failures... lol

[shan]

hmm....let's see...
here's hello.
5d41402abc4b2a76b9719d911017c592
here's jello.
7aa6991a62353dd2761280cf592542dc
here's ****.
4229d691b07b13341da53f17ab9f2416
here's jell.
71ed454e7f49bd39c3bd1087e6524d32
good luck!

i guess if you wrote some sort of app to get enough possible combonations to get a general idea what's what and where it is...you may be able to crack it...but it'd be **** TOUGH! hahahah....like I said, good luck!

[BlazingWolf]

guess if you wrote some sort of app to get enough possible combonations to get a general idea what's what and where it is...you may be able to crack it...but it'd be **** TOUGH! hahahah....like I said, good luck!

You'd have to know exactly how it works or someone would have already done that.

[winblowz]

ahh... cracking the md5 is hopeless-I thought about doing it for an advanced computers project, but then I decided screw it-I'd dfail the class for not completing my project lol.



Al

[Dj_Diablo]

Think about it like this...

With normal encryption, the encrpted output's size varies on the input being encrypted. So if I encrypt the word "hello", the encrypted verison will be, say 500bytes. If I then encrypt longer text, such as a file, the encrypted output will be, say 700kb. This is reversable because the encrypted output will still technically contain the original text, except it is jumpled.

Now think of MD5. If I hash the word "hi", I get a 32 character output. If I hash a 2mb essay, I still get a 32 character output. There is no way you can "uncompress" 32 character back into 2mb worth of data. Get what I am saying?

That is why MD5 is irreversible.

Edit another example:

Say you came up to me and you said the following sentence:
"Hello, my name is Bob. I am talking to you"

I could just reply saying, "1"

Think of the above scenario as MD5. By using the sentence as input, MD5 gives you an output that is unique to what you said to me, but has nothing to do with the original data in a sense. There is no way to uncompress "1" into a sentence again, but if someone says the same sentence to me again, my output will always be "1".