METHOD AND SYSTEM FOR END-TO-END SESSION KEY NEGOTIATION WHICH SUPPORT LAWFUL INTERCEPTION

摘要

A method and system for end-to-end session key negotiation which support lawful interception are disclosed. The method includes: a first terminal carries out a session root key negotiation with a first Identification Location Register (ILR) to which said first terminal belongs, generates a session root key Kas for the session and saves it; said first terminal then generates a session key according to a first parameter including a first self-generated random number and Kas, and initiates an end-to-end session key request to a second terminal; the key negotiating parameters carried in said request include a first ciphertext containing the first random number information encrypted by Kas and a first identification information of the session. The second terminal sends the received key negotiating parameters to the first ILR; using Kas, said first ILR obtains the first random number from decryption of the first ciphertext, generates the session key in the same way as the first terminal and saves the key, then sends it to the second terminal in ciphertext. The second terminal then decrypts the ciphertext and acquires the session key contained within it. The first terminal then carries out a session with the second terminal by using the session key, said session key including the session encryption key.