Jump to content
Sign in to follow this  
hisoka

password of RC4 encryption

Recommended Posts

This is about RC4 encryption .

It is well known that in RC4 encryption , the keystream  is xored with the plaintext to give the ciphertext . It is well known too that , in order to generate the keystream , which is  needed in the process of encryption as i mentioned  ,  a user defined password is used . That is to say a password is needed to generate the keystream . So my question is this :

If we , ONLY , know the ciphertext and know that the PASSWORD used to generate the keystream - and therefore that ciphertext - is an ENGLISH WORD  composed of 6 characters  . Is it possible , based only on these two piece of information ,  to get this English word or this password . If yes . HOW?

Share this post


Link to post
Share on other sites

It sounds like you want to brute force it.  That means trying all combinations.  So you just need to loop through all possible 6-character words (I'm assuming case matters, so that's 52 letters, assuming no accented or non-Latin characters), and try each one with all possible inputs up to the length you want to check, to see if that passphrase plus that input results in the output you're looking for.  If you start this now then one of your descendants will probably get the answer.

I'm only partly serious.  There are several descriptions of attacks against RC4 that you may be able to use depending on how the original keystream was generated.

Share this post


Link to post
Share on other sites
Quote

There are several descriptions of attacks against RC4 that you may be able to use depending on how the original keystream was generated.

 there are of course  but I could not find methods , concerning RC4 , that can help me recover the password used in RC4 encryption supposing that the password is an English word of 6 letters . Could you describe some because I could not find concrete ones .

Quote

It sounds like you want to brute force it

do you know  a software or a tool that can be used to  brute force this 6 letters password  ? I looked for hours in the internet but I could not find a tool .

Share this post


Link to post
Share on other sites

I have not done any research into breaking RC4, I'm sorry.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

×