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The security of GRID routing protocol based on location information in mobile Ad Hoc networks needs to be verified, so a formal method is introduced to achieve this goal in this paper. Based on BAN logic, this method also combines the characteristics of Ad Hoc network routing protocal. The analysis results show that the protocol has security vulnerabilities in the route maintenance phase which cannot be pinpointed. From the analysis results, this method is proved to be effective and lay the foundation for the improvement of GRID protocol in the future.

Frequency hopping communication is widely used in military communications at home and abroad. In the case of single-channel reception, it is scarce to process multiple frequency hopping signals both effectively and simultaneously. A method of hybrid FH signals selection and blind parameter estimation is proposed. The method makes use of spectral transformation, spectral entropy calculation and PRI transformation basic theory to realize the sorting and parameter estimation of the components in the hybrid frequency hopping signal. The simulation results show that this method can correctly classify the frequency hopping component signal, and the estimated error of the frequency hopping period is about 5% and the estimated error of the frequency hopping frequency is less than 1% when the SNR is 10dB. However, the performance of this method deteriorates seriously at low SNR.

The key management is important issues in multicast communication of satellite network. This paper presented a threshold value -based group key management scheme. In the scheme, ground control center is designed as ID registration authority. A group key share distributed center was created through choosing n satellites which can keep long time visible. The performance of group key generation algorithm was improved. And communication load was reduced. Group key negotiation didn't need secure channel. So system resources were saved. Performance analysis showed that this scheme not only has strong security, but also has less computational and communication costs.

This study proposed a new evaluation theory about the enterprise technical competitive capacity called Cross Comparision Analysis theory, and established the Cross Comparision Analysis methods for practice approach, then confirmed this theory by using the empirical study in the appraisal of enterprise competitive capacity.