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Got 'em! Researchers Steal Crypto Keys From Amazon Cloud

Artist's impression of a hacker.

Researchers at Worchester Polytechnic Institute have demonstrated how an instance of Amazon EC2 may be used to recover the full RSA key from another Amazon instance.

Credit: Thinkstock

Worchester Polytechnic Institute (WPI) researchers have demonstrated how to use one instance of Amazon EC2 to recover the full 2,048-bit RSA key from a separate Amazon instance.

"We exploit the [last-level cache (LLC)] to recover the secret key of a modern sliding-window exponentiation-based implementation of RSA, across cores and without relying on deduplication," the researchers say.

They note malicious hackers could use this strategy to intercept the targeted entity's encrypted communications and extract potentially valuable information. For this attack to work, both the attacker's Amazon account and the target Amazon account containing the private RSA key must be on the same hardware chip or chip set. "Everything must work in concert together and it is highly difficult to pull off," notes Comodo's Robin Alden.

The researchers say their technique highlights the need for deploying stronger isolation techniques in public clouds. Experts recommend providers patch the weaknesses that make these types of attacks possible, and smarter cache management policies for hardware and software could prevent side-channel leakages and future exploits. "A more random placement policy would make it tougher for attackers to land on the same [central processing unit] or hardware as that of the intended target," says Ciphercloud's Sundaram Lakshmanan.

From InfoWorld
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