Patent ID: 9078126
Filing Date: 2015-07-07
Classification: H04L,H04W

Abstract:
1. A method of sharing a session key between wireless communication terminals based on a Diffie-Hellman (DH) protocol, the method comprising: generating a public key by using an own private key; generating a message including the public key and a first random number; encoding the message using an own secret key to exchange an encrypted message with the other terminal, wherein the message further comprises an identifier and a reflection attack verification value and wherein the secret key is a disposable key; decoding the encrypted message of the other terminal by receiving a secret key of the other terminal; checking the reflection attack verification value of the other terminal included in the decoded message; generating an authentication code by calculating the first random number and a second random number included in the decoded message, wherein the first and second random numbers are comprised of bit streams having a value of 0 or 1, wherein the generating of the authentication code comprises performing an exclusive OR operation on the first random number and the second random number, wherein the authentication code is divided into n bits (where n is a natural number of 2 or more), wherein the divided authentication code corresponds to one grid, and wherein each grid is indicated by one color; obtaining a medium value from the authenticated code; and generating a session key by using the public key included in the decoded message of the other terminal, wherein the obtaining of the medium value from the authentication code comprises: wherein the number S′ of grids required to display the medium value is obtained by the following equation: where S is the number of grids required when the number of colors for displaying the medium value is 2, k is the number of colors used to display the medium value and is 2