Discovery and Exploitation of New Biases in RC4

نویسندگان

  • Pouyan Sepehrdad
  • Serge Vaudenay
  • Martin Vuagnoux
چکیده

In this paper, we present several weaknesses in the stream cipher RC4. First, we present a technique to automatically reveal linear correlations in the PRGA of RC4. With this method, 48 new exploitable correlations have been discovered. Then we bind these new biases in the PRGA with known KSA weaknesses to provide practical key recovery attacks. Henceforth, we apply a similar technique on RC4 as a black box, i.e. the secret key words as input and the keystream words as output. Our objective is to exhaustively find linear correlations between these elements. Thanks to this technique, 9 new exploitable correlations have been revealed. Finally, we exploit these weaknesses on RC4 to some practical examples, such as the WEP protocol. We show that these correlations lead to a key recovery attack on WEP with only 9800 encrypted packets (less than 20 seconds), instead of 24200 for the best previous attack.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Proof of Empirical RC4 Biases and New Key Correlations

In SAC 2010, Sepehrdad, Vaudenay and Vuagnoux have reported some empirical biases between the secret key, the internal state variables and the keystream bytes of RC4, by searching over a space of all linear correlations between the quantities involved. In this paper, for the first time, we give theoretical proofs for all such significant empirical biases. Our analysis not only builds a framewor...

متن کامل

Proving TLS-attack related open biases of RC4

After a series of works on RC4 cryptanalysis in last few years (published in flagship cryptology conferences and journals), the most significant (and also very recent) attack on the cipher has been the discovery of vulnerabilities in the SSL/TLS protocol, by AlFardan, Bernstein, Paterson, Poettering and Schuldt. They ran extensive computations to identify significant short-term single-byte keys...

متن کامل

Big Bias Hunting in Amazonia: Large-Scale Computation and Exploitation of RC4 Biases (Invited Paper)

RC4 is (still) a very widely-used stream cipher. Previous work by AlFardan et al. (USENIX Security 2013) and Paterson et al. (FSE 2014) exploited the presence of biases in the RC4 keystreams to mount plaintext recovery attacks against TLS-RC4 and WPA/TKIP. We improve on the latter work by performing large-scale computations to obtain accurate estimates of the single-byte and double-byte distrib...

متن کامل

Predicting and Distinguishing Attacks on RC4 Keystream Generator

In this paper we analyze the statistical distribution of the keystream generator used by the stream ciphers RC4 and RC4A. Our first result is the discovery of statistical biases of the digraphs distribution of RC4/RC4A generated streams, where digraphs tend to repeat with short gaps between them. We show how an attacker can use these biased patterns to distinguish RC4 keystreams of 2 bytes and ...

متن کامل

Dependence in IV-Related Bytes of RC4 Key Enhances Vulnerabilities in WPA

The first three bytes of the RC4 key in WPA are public as they are derived from the public parameter IV, and this derivation leads to a strong mutual dependence between the first two bytes of the RC4 key. In this paper, we provide a disciplined study of RC4 biases resulting specifically in such a scenario. Motivated by the work of AlFardan et al. (2013), we first prove the interesting sawtooth ...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2010