Abstract
The general auto orrelation proposed is the extension of the traditional auto orrelation. Besides the same ability as auto orrelation to reveal the haracteristics of the linear structures, the strict avalanche criterion(SAC)and the propagation criterion(PC)of degree k,the general autocorrelation is apable of finding the order of SAC and PC which is a capability that auto orrelation does not possesses.The application on AES S-box shows the SAC and PC characteristics of the eight AES Boolean functions.