About: Correlation attack

In cryptography, correlation attacks are a class of known plaintext attacks for breaking stream ciphers whose keystream is generated by combining the output of several linear-feedback shift registers (LFSRs) using a Boolean function. Correlation attacks exploit a statistical weakness that arises from certain choices of the Boolean function. The cipher is not inherently insecure if there is a choice of the Boolean function that avoids this weakness. As with all attack methods, this should be accounted for when designing an encryption system.