Cryptographic boolean functions with a large number of variables

To resist those known attacks, Boolean functions used in stream ciphers should have large input size (e.g. 32-variable). However, up to now, for n > 20, very few n-variable Boolean function with good cryptographic properties can be implemented efficiently. This paper tries to solve this problem, and puts forward a method to construct cryptographically significant Boolean functions with large input size. The functions constructed by us have good cryptographic properties, and thus can resist all the main attacks. Moreover, they can be implemented efficiently. Hence, they can be used to design the real-life cipher.