Claims by a cryptography researcher this week about weaknesses in the RC4 algorithm used in SSL/TLS certificates is being downplayed by the group known as the Certificate Authority Security Council (CASC) which was recently established to address questions on security in this area.
"While interesting, the attacks don't represent an immediate practical threat to users of SSL/TLS (including online banking, e-commerce, social networking, etc.)," said Rick Andrews, technical director at Symantec on behalf of CASC. "Such attacks require an attacker to run malicious software on a user's computer which would connect to a particular website and send the same message over and over again many times. In fact, if the attacker's software could send the same message over and over 10 times per second, it would still take more than three years for the attack to succeed." The group also commented on its blog at the questions raised.
The CASC was responding to inquiries about the article "Cryptographers Demonstrate New Crack for Common Web Encryption" by Forbes writer Andy Greenberg, which noted that at the Fast Encryption conference in Singapore this week, University of Illinois at Chicago Professor Dan Bernstein presented a method for breaking Transport Layer Security as well as Secure Sockets Layer. The article suggested the attack would take 32 hours to perform.
However, downplaying the practical value of the attack, the CASC, which includes Comodo, DigiCert, GlobalSign, GoDaddy, Symantec and Trend Micro, appeared to acknowledge the validity of this new research on weaknesses in the RC4 algorithm, originally invented by famed cryptographer Ron Rivest.
"The designers of the SSL/TLS protocol anticipated that algorithms would become weaker over time, so the protocol was designed to support the easy addition of new algorithms. Hence a weakness in one algorithm does not mean that SSL/TLS is broken. Newer, stronger algorithms have already been developed and incorporated into the latest implementations of SSL/TLC," Andrews said on behalf of CASC. "What's needed now is for users of Web server and browser software to update to the newest versions to minimize or eliminate the use of weakened algorithms."
Andrews concluded for CASC, "The fact remains, SSL/TLS is still the most scalable, efficient cryptographic protocol now and, with the number of researchers focused on its protocols, will only get stronger in the future."
Ellen Messmer is senior editor at Network World, an IDG publication and website, where she covers news and technology trends related to information security. Twitter: @MessmerE. Email: [email protected]
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