# RC4 using a key without nonce's or IV's [duplicate]

I'm researching RC4 and I am trying to recreate a condition where RC4 is crackable. However I can't quite find the article/resource I need to find the weakness for an implementation like this (python):

from Crypto.Cipher import ARC4
f = open('key.txt')

o = open('output.txt','w')
f = open('input.txt')
for line in f:
cipher = ARC4.new(key)
print >>o, cipher.encrypt(line).encode('hex')


I know the weakness is that the same key is used to encrypt the traffic, however I need a hint as to how this might impact the security of the algorithm.

• Hint: what would you get if you xor two of the ciphertexts together? – poncho May 26 '16 at 12:24
• The key stream? – Don May 26 '16 at 12:34
• Potentially interesting as it contains links to papers and infos related to your Q as well as some python files to play with in the “Resources” section $\rightarrow$ rc4nomore.com – e-sushi May 26 '16 at 12:51
• @Don, no, you get the xor of the two plaintexts. – mikeazo May 26 '16 at 13:01