Maximum correlation analysis of nonlinear combining functions in stream ciphers. (English) Zbl 1015.94007
Summary: The maximum correlation of a Boolean function to all Boolean functions of a subset of its input variables is investigated. A relationship is derived between the maximum correlation and the mutual information between the output of a balanced Boolean function and a subset of its random input variables. For bent functions (which are never balanced), both the mutual information and the maximum correlation are bounded and shown to be small in a strong sense.
MSC:
94A55 | Shift register sequences and sequences over finite alphabets in information and communication theory |
06E30 | Boolean functions |
94A60 | Cryptography |
65C10 | Random number generation in numerical analysis |