Non-access stratum ciphertext decryption method and device

• Main Authors: LI DAOYUAN, LIANG RENKE, WU RUI, CAO DIE, HUANG WEI, ZHU WENHAI, CHANG WEN, RAO BINGWANG, QI JINGHAN
• Format: Patent
• Language: Chinese; English
• Published: 27.10.2023
• Subjects: ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHICCOMMUNICATION; WIRELESS COMMUNICATIONS NETWORKS

The invention discloses a non-access layer ciphertext decryption method and device, and the method comprises the steps: carrying out the matching of a corresponding target KSI and a plurality of undetermined security contexts associated with the target KSI from a mapping database when the AKA authentication between a user side and a core network is passed and a request signaling is received, carrying out the integrity verification of the request signaling, and carrying out the decryption of the undetermined security contexts. And determining a current security context from a plurality of undetermined security contexts, when a non-access stratum ciphertext is received, calculating an NAS connection identifier in the current security context according to an NAS serial number extracted from the non-access stratum ciphertext to obtain a target security context, and decrypting the non-access stratum ciphertext by adopting the target security context to generate a non-access stratum plaintext. The technical problem