5G UE SUCI Generation for Legacy SIM Security
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Solution Overview
Problem
Legacy SIM cards used with 5G UEs expose IMSIs in plain text during network registration, compromising security and preventing seamless compatibility and secure 5G service provision.
Innovation Solution
A 5G UE generates a Subscription Concealed Identifier (SUCI) by encrypting the IMSI from a legacy SIM using a network public key stored in its memory, allowing secure 5G registration and service access without exposing the IMSI.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a legacy SIM card is used with a 5G UE, then compatibility is maintained and users can continue using existing SIM cards, but security is compromised because the IMSI is exposed in plain text during network registration
Solution Approach 1:
The patent introduces an intermediary encryption process using a public key stored in the UE's memory. The IMSI from the legacy SIM is encrypted with this public key to generate a SUCI before transmission to the network. This intermediary encryption layer allows legacy SIMs to work with 5G networks while preventing plain text exposure of the IMSI.
Solution Approach 2:
The patent changes the parameter of the subscriber identifier from plain text IMSI to encrypted SUCI. By transforming the IMSI through encryption with the public key, the system maintains compatibility with legacy SIMs while improving security posture to meet 5G requirements.
2Productivity
If the IMSI is transmitted in plain text during network registration, then the registration process is simple and fast, but security is compromised allowing unauthorized interception of the IMSI
Solution Approach 1:
The patent performs preliminary encryption of the IMSI to create a SUCI before the network registration process begins. The UE encrypts the IMSI using the stored public key in advance, so that when registration occurs, the transmitted identifier is already protected. This preliminary security action maintains registration efficiency while preventing interception.
3Reliability
If 5G security standards requiring encrypted subscriber identifiers are implemented, then security is enhanced, but compatibility with legacy SIM cards is lost
Solution Approach 1:
The patent makes the UE capable of serving multiple functions: it can read IMSI from legacy SIMs, encrypt them using stored public keys to create SUCI, and transmit the encrypted identifiers for 5G registration. This multi-functionality allows the system to support both legacy SIM infrastructure and 5G security requirements simultaneously.
Data Source
AI summary
A 5G user equipment (UE) can register for 5G services with a telecommunication network in part using a Subscription Concealed Identifier (SUCI), an encrypted version of a subscriber identifier, so that the actual subscriber identifier is not exposed during network registration. Legacy SIMs originally deployed for 4G/LTE and other legacy wireless access technologies store an international mobile subscriber identity (IMSI), but do not store a network public key needed to generate a SUCI. However, a 5G UE can still use a legacy SIM to securely obtain 5G services by encrypting the IMSI from the legacy SIM using a network public key stored in the 5G UE's own memory to generate a SUCI, and then transmitting the generated SUCI to the telecommunication network during network registration. Accordingly, the IMSI on the legacy SIM is not exposed during network registration.