Nadhem AlFardan,Royal Holloway, University of London;Daniel J. Bernstein,University of Illinois at Chicago and Technische Universiteit Eindhoven;Kenneth G. Paterson,Bertram Poettering, andJacob C.N. Schuldt,Royal Holloway, University of London
Abstract:
The Transport Layer Security (TLS) protocol aims to provide confidentiality and integrity of data in transit across untrusted networks. TLS has become the de facto protocol standard for secured Internet and mobile applications.TLS supports several symmetric encryption options, including a scheme based on the RC4 stream cipher. In this paper, we present ciphertext-only plaintext recovery attacks against TLS when RC4 is selected for encryption. Our attacks build on recent advances in the statistical analysis of RC4, and on new findings announced in this paper. Our results are supported by an experimental evaluation of the feasibility of the attacks. We also discuss countermeasures.
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@inproceedings {182942, author = {Nadhem AlFardan and Daniel J. Bernstein and Kenneth G. Paterson and Bertram Poettering and Jacob C. N. Schuldt}, title = {On the Security of {RC4} in {TLS}}, booktitle = {22nd USENIX Security Symposium (USENIX Security 13)}, year = {2013}, isbn = {978-1-931971-03-4}, address = {Washington, D.C.}, pages = {305--320}, url = {https://www.usenix.org/conference/usenixsecurity13/technical-sessions/paper/alFardan}, publisher = {USENIX Association}, month = aug }
I am a seasoned cybersecurity expert with a deep understanding of cryptographic protocols and their vulnerabilities. My expertise spans various aspects of network security, encryption, and the intricacies of cryptographic algorithms. To substantiate my proficiency, let me delve into the article you've provided, titled "On the Security of RC4 in TLS," authored by Nadhem AlFardan, Daniel J. Bernstein, Kenneth G. Paterson, Bertram Poettering, and Jacob C. N. Schuldt, from the 22nd USENIX Security Symposium in 2013.
The authors address the Transport Layer Security (TLS) protocol, which is a critical component in ensuring the confidentiality and integrity of data during transit across untrusted networks. TLS has evolved into the standard protocol for securing internet and mobile applications, playing a pivotal role in safeguarding sensitive information from malicious actors.
The focus of this paper is on symmetric encryption options within TLS, particularly on a scheme based on the RC4 stream cipher. The authors present ciphertext-only plaintext recovery attacks against TLS when RC4 is chosen for encryption. These attacks leverage advancements in the statistical analysis of RC4, along with novel findings introduced in the paper. The significance of their research is underscored by experimental evaluations confirming the feasibility of the proposed attacks.
The mention of "ciphertext-only plaintext recovery attacks" emphasizes the severity of the vulnerabilities identified in the use of RC4 within TLS. Ciphertext-only attacks imply that the attacker has access only to the encrypted data and not the corresponding plaintext. The ability to recover plaintext from such a limited vantage point signifies a significant security concern.
The authors' reliance on statistical analysis of RC4 highlights the importance of understanding cryptographic algorithms not only from a theoretical standpoint but also through empirical investigation. This demonstrates a comprehensive approach to cryptographic research, incorporating both mathematical rigor and real-world applicability.
Additionally, the paper discusses countermeasures to mitigate the identified vulnerabilities. The term "countermeasures" suggests proactive measures or defenses that can be implemented to safeguard systems against potential threats. This reflects the authors' commitment to not only identifying weaknesses but also proposing practical solutions to enhance the security of the TLS protocol.
In summary, the article delves into the intricate details of the TLS protocol, specifically focusing on the security implications of employing the RC4 stream cipher. The combination of theoretical analysis, experimental evaluation, and proposed countermeasures showcases the authors' expertise in cryptographic research and their dedication to addressing real-world security challenges.
RC4 is one of the most commonly used stream ciphers, having been used in Secure Socket Layer (SSL)/ Transport Layer Security (TLS) protocols, IEEE 802.11 wireless LAN standard, and the Wi-Fi Security Protocol WEP (Wireless Equivalent Protocol).
The attacker can then use a brute-force attack using LSB values. The RC4 algorithm, a stream cipher, has historically been used in various encryption protocols, including Transport Layer Security (TLS) and its predecessor, Secure Sockets Layer (SSL).
Symmetric key algorithm: RC4 is a symmetric key encryption algorithm, which means that the same key is used for encryption and decryption. Stream cipher algorithm: RC4 is a stream cipher algorithm, which means that it encrypts and decrypts data one byte at a time.
AES-128 is considered more secure than RC4. RC4 is an old stream cipher which is considered broken. That is: it is possible to obtain information about the key stream and therefore plaintext.
RC4 (also known as Rivest Cipher 4) is a form of stream cipher. It encrypts messages one byte at a time via an algorithm. Plenty of stream ciphers exist, but RC4 is among the most popular.
Not only is RC4 increasingly irrelevant as a BEAST workaround, there has also been mounting evidence that the RC4 cipher is weaker than previously thought. In 2013, biases in RC4 were used to find the first practical attacks on this cipher in the context of TLS.
In this manner, any server or client that is talking to a client or server that must use RC4 can prevent a connection from occurring. Clients that deploy this setting will be unable to connect to sites that require RC4, and servers that deploy this setting will be unable to service clients that must use RC4.
Luckily, detecting Kerberos tickets that are encrypted using RC4 can also be achieved without expensive SIEM implementations. Simply trawling through the logs on your Domain Controllers with Windows PowerShell uncovers this usage.
advantage of the proposed RC4-EA method is to increase the security of the system, by generating the secret keys dynamically and randomly. Which leads to, overcome the drawback of a non-random secret key as a seed in the original RC4 encryption algorithm. Hence, the final key stream can not be cracked by the attacker.
The encryption delay overhead using RC4 is less than the overhead using AES and DES algorithms, but AES is much safer than RC4. Therefore, we conclude that both of AES and RC4 can secure high- bandwidth real time streaming, AES gets much more safety and RC4 get much more ...
To encrypt a text, this key stream is XORed with a plaintext, and decryption is done by XORing the ciphertext with the key stream again. RC4 is broken in a variety of situations. If you just naively use it twice on two different plaintexts then that is it, it's broken.
SSL/TLS uses both asymmetric and symmetric encryption to protect the confidentiality and integrity of data-in-transit. Asymmetric encryption is used to establish a secure session between a client and a server, and symmetric encryption is used to exchange data within the secured session.
The main difference between RC4 and AES is that AES is a block cipher and RC4 is a stream cipher. Symmetric algorithm classes include block encryption and stream encryption. A block cipher encodes plain text in block sizes, whereas a stream cipher encodes bit by bit, simulating the flow of a stream.
RC4 is faster than RSA. In software, it is roughly one thousand times faster than RSA. RSA is still sufficiently fast for most high- speed applications. By contrast, the slowness of RSA due to the high complexity of modular exponentiation is not usually acceptable for encryption of large files.
We can disable 3DES and RC4 ciphers by removing them from registry HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Cryptography\Configuration\Local\SSL\00010002 and then restart the server.
Introduction: My name is Kerri Lueilwitz, I am a courageous, gentle, quaint, thankful, outstanding, brave, vast person who loves writing and wants to share my knowledge and understanding with you.
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