Measurement Of Signal Transmission Time And Code Execution Time Based On High Precision Timestamp

Network security has always been the focus of research.Network security analysis often refers to the analysis of network behavior,such as network information flow or program code execution,and time is an important feature of network security behavior analysis.But the traditional security behavior analysis often neglects the dimension of time.The reason is that the accuracy of time in the network environment is not enough to measure network behavior,and the common way to obtain high-precision time is not suitable for network behavior analysis,such as the high cost of atomic clocks and the need for master-slave time synchronization in PTP system design.Aiming at the above two problems,this paper designs and implements a signal timestamp generator which adds high-precision time to network data package.It associates time with network security behavior analysis,solves the problem that there is no cheap nanosecond high-precision network signal detection equipment at present,and proposes a hardware device based on which network signal can be accurately measured in two networks.The scheme of transmission delay between network nodes is presented,and the corresponding delay extraction model and delay analysis algorithm are given.At the same time,the network information transmission behavior and program code execution behavior are analyzed based on the network signal delay measurement scheme.In the analysis of transmission behavior,the network information is located by measuring the transmission delay of network signal in the network;and in the analysis of program code execution behavior,the time characteristics of code are analyzed by measuring assembly instructions and code segments.The contributions of this paper include:(1)Adding high-precision timestamps and generating data frames with high-precision timestamps when network signals are detected in the physical layer can realize the study of network security from the perspective of time;(2)The measurement results of transmission delay of network signals between two network nodes are obtained,and the results show that the transmission delay of network signals between two network nodes can be calculated through the transmission delay of network signals between two network nodes.The length of network line between two nodes can calculate the actual physical distance between nodes,which effectively improves the accuracy of entity resource location in Network Space Surveying and mapping,and realizes the physical location of network information.The results also show that the security status of network equipment can be judged by analyzing the characteristics of network equipment's delay distribution;(3)The measurement results of assembly instruction delay and the time comparison before and after code modification without changing the function of code segment are given.It is proved that the proposed scheme can accurately measure the nanosecond execution time of code bypass and apply this time to judge whether the code has been tampered with or not.This paper introduces the time perspective to study and discuss the time characteristics of network information transmission behavior and code execution behavior in network security,gives the time-based research direction of network security behavior analysis,and expands the application of GNSS satellite timing.