Patent ID: 7636845

Claim:
A system for preventing IP (Internet Protocol) allocation to a cloned mobile communication terminal, comprising: a mobile communication terminal to generate a first hash value obtained by hashing a user key inputted by a user and an ESN (Electronic Serial Number) with a hash function, and to transmit the first hash value to an HA (Home Agent) of a mobile communication system; and the HA to register the first hash value transmitted from the mobile communication terminal, to compare a second hash value included in an IP registration request message (RRQ) with the registered first hash value to perform an IP registration request of the mobile communication terminal, and to perform an IP registration process if the compared values match, wherein the mobile communication terminal includes a mobile communication terminal processing module, comprising: a storage part to store a first variable having network access identification information, a second variable having a hash value, and a third variable set to ‘TRUE’ or ‘FALSE’ according to whether or not the hash value is registered; an initialization part to set the first and second variables to ‘NULL’ and to set the third variable to ‘FALSE’ when the ESN is input; a user key input part to provide UI (User Interface) to the user and to receive the user key from the user through the UI when the first and second variables are set to ‘NULL’; a hash value generation part to generate the first hash value by hashing the user key inputted by the user key input part and the ESN with the hash function, and to set the first and second variables to the generated first hash value; an IP registration request part to transmit the IP registration request message (RRQ) including the first and second variables to the HA; and a hash value registration check part to store network access identification information, which is predetermined between the mobile communication terminal and the HA, in the first variable and to change the third variable to ‘TRUE’ when an IP registration reply message (RRP) transmitted from the HA is a message indicating ‘registration of hash value’.