Time synchronization method in wireless sensor network

A time synchronization method in a wireless sensor network, comprising:

• allowing a lower reference node to broadcast a first sync reference packet and writing a first reception time indicating a reception time of the first sync reference packet at an upper node wherein the first reception time is a time of receiving the first sync reference packet by the upper node;
• allowing the lower reference node to broadcast a second sync reference packet including the first reception time;
• allowing at least one node adjacent to the lower reference node to perform time synchronization on the basis of the second sync reference packet;
• allowing the lower reference node to estimate a time of receiving the first sync reference packet by the upper node and calculate a first reception estimation time based on the estimated reception time;
• and
• allowing a determination node that is a plurality of hops anterior to the upper node to compare the first reception time and the first reception estimation time and determine whether a capture attack on the upper node has occurred.

A time synchronization method in a wireless sensor network, comprising:

• allowing a lower reference node to broadcast a first sync reference packet;
• allowing the lower reference node to broadcast a second sync reference packet including a first reception time corresponding to the reception time of the first sync reference packet by an upper node;
• allowing at least one node adjacent to the lower reference node to perform time synchronization on the basis of the second sync reference packet;
• allowing the lower reference node to estimate the reception time of the first sync reference packet by the upper node and calculate a first reception estimation time;
• and
• allowing a determination node that is a plurality of hops anterior to the upper node to compare the first reception time and the first reception estimation time and determine whether a capture attack on the upper node has occurred,
• further comprising:
• allowing the at least one node to estimate the reception time of the first sync reference packet by the upper node and calculate a second reception estimation time;
• and
• allowing the determination node to compare the first reception estimation time and the second reception estimation time and determine whether the capture attack on the lower reference node has occurred,
• wherein the calculating of the second reception estimation time includes:
• allowing the at least one node to calculate a time difference between the time synchronization start request packet reception time of the at least one node and the time synchronization start request packet reception time of the lower reference node;
• allowing the at least one node to estimate the response packet reception time of the lower reference node using the response packet reception time of the at least one node and the time difference;
• and
• allowing the at least one node to calculate the second reception estimation time using the first reception time and the response packet transmission time acquired from the response packet, the first sync reference packet transmission time acquired from the first sync reference packet, and the estimated response packet reception time of the lower reference node.