Method and apparatus for secure communication between cryptographic systems using real time clock

摘要

Provided are a method and apparatus for secure communication between cryptographic systems using a Real Time Clock (RTC). The method and apparatus allow a transmitting cryptographic system to transfer partial RTC data and a receiving cryptographic system to restore entire RTC data, thereby minimizing data to be transferred between the cryptographic systems. The method includes: calculating a largest RTC deviation between a transmitting cryptographic system and a receiving cryptographic system; calculating the smallest number of bits of partial data on an RTC required for restoring entire data on the RTC on the basis of the calculated largest RTC deviation; calculating the partial RTC data on the basis of the calculated smallest number of bits of the partial RTC data; and transferring the calculated partial RTC data to the receiving cryptographic system.