Certificate-based local UE authentication

Patent metadata

Field	Value
Publication number	US-11838428-B2
Application number	US-202218065914-A
Country	US
Kind code	B2
Filing date	Dec 14, 2022
Priority date	Dec 20, 2021
Publication date	Dec 5, 2023
Grant date	Dec 5, 2023

Abstract

According to an example aspect of the present invention, there is provided a method comprising: generating a certificate comprising an identifier of a base station, a public key of the base station, and a public key of a terminal; signing the certificate by a signature based on a private key belonging to the public key of the base station; sending the signed certificate to the terminal using an established security association; monitoring whether the base station receives a request for local authentication of the terminal, wherein the request comprises an encrypted certificate unit and a base station identifier; checking whether the base station identifier is the identifier of the base station and, if it is, decrypting the encrypted certificate unit using the private key; and using the public key of the terminal for a communication with the terminal if the certificate unit comprises the signed certificate.

First claim

The invention claimed is:

1. An apparatus comprising
at least one processor; and
at least one memory including computer program code, the at least one memory and computer program code configured to, with the at least one processor, cause the apparatus at least to:
check whether a terminal receives, using an established security association between the terminal and a first base station, from the first base station, a first local authentication certificate, wherein the first local authentication certificate comprises a public key of the terminal, a public key of the first base station, and a base station identifier of the first base station;
store the first local authentication certificate if the terminal receives the first local authentication certificate;
monitor whether the terminal is to be authenticated; and
if the terminal is to be authenticated:
retrieve the public key of the first base station and the base station identifier from the first local authentication certificate;
encrypt a certificate unit with the public key of the first base station to create an encrypted certificate unit, wherein the certificate unit comprises the first local authentication certificate; and
send, to a second base station, a request for local authentication of the terminal, wherein the request for local authentication comprises the encrypted certificate unit and the base station identifier, and the base station identifier is not encrypted in the request for local authentication.

2. The apparatus according to claim 1 , wherein the local authentication certificate further comprises a key identifier; and wherein the at least one processor and the at least one memory including the computer program code are further configured to cause the apparatus to:
retrieve the key identifier from the first local authentication certificate; and
send the key identifier in the request for local authentication, wherein the key identifier is not encrypted in the request for local authentication.

3. The apparatus according to claim 2 , wherein the at least one processor and the at least one memory including the computer program code are further configured to cause the apparatus to:
select a nonce; and at least one of
protect an uplink message from the terminal to the second base station using the nonce and the communication comprises the uplink message; or
verify a downlink message received from the second base station to the terminal using the nonce and the communication comprises the downlink message; wherein

the certificate unit comprises a combination of the first local authentication certificate and the nonce.

4. The apparatus according to claim 1 , wherein the at least one processor and the at least one memory including the computer program code are further configured to cause the apparatus to:
select a nonce; and at least one of
protect an uplink message from the terminal to the second base station using the nonce and the communication comprises the uplink message; or
verify a downlink message received from the second base station to the terminal using the nonce and the communication comprises the downlink message; wherein

the certificate unit comprises a combination of the first local authentication certificate and the nonce.

5. The apparatus according to claim 4 , wherein the at least one processor and the at least one memory including the computer program code are further configured to cause the apparatus to:
determine the base station as authenticated if the downlink message from the second base station to the terminal is verified using the nonce.

6. The apparatus according to claim 1 , wherein the at least one processor and the at least one memory including the computer program code are further configured to cause the apparatus to:
generate a pair of a private key of the terminal and the public key of the terminal belonging to the private key of the terminal; and
send the public key of the terminal to the first base station using the established security association prior to the checking whether the terminal receives, using the established security association, the first local authentication certificate.

7. The apparatus according to claim 1 , wherein the at least one processor and the at least one memory including the computer program code are further configured to cause the apparatus to:
check, for each one of plural base stations including the first base station, whether the terminal receives, using a respective established security association between the terminal and the respective base station, from the respective base station, a respective local authentication certificate, wherein the respective local authentication certificate comprises a respective public key of the terminal, a public key of the respective base station, and a base station identifier of the respective base station;
store, for each one of the plural base stations, the respective local authentication certificate if the terminal receives the respective local authentication certificate; and
select one of the stored plural local authentication certificates as the first local authentication certificate.

8. An apparatus comprising at least one processor; and
at least one memory including computer program code, the at least one memory and computer program code configured to, with the at least one processor, cause the apparatus at least to:
generate a local authentication certificate, wherein the local authentication certificate comprises an identifier of a base station, a public key of the base station, and a public key of a terminal;
sign the local authentication certificate by a signature based on a private key of the base station, wherein the private key of the base station is belonging to the public key of the base station;
send the signed local authentication certificate to the terminal using an established security association between the base station and the terminal;
monitor whether the base station receives a request for local authentication of the terminal, wherein the request for local authentication comprises an encrypted certificate unit and a base station identifier;
check, without decrypting the received base station identifier, whether the received base station identifier is the identifier of the base station if the base station receives the request for local authentication;
decrypt the encrypted certificate unit using the private key of the base station to create a certificate unit if the received base station identifier is the identifier of the base station;
check whether the certificate unit comprises the local authentication certificate signed by the signature; and
use the public key of the terminal for a communication with the terminal if the certificate unit comprises the local authentication certificate signed by the signature.

9. The apparatus according to claim 8 , wherein
the local authentication certificate comprises additionally a key identifier;
the key identifier identifies the public key of the base station; and
the received request for local authentication comprises a received key identifier;
wherein the at least one processor and the at least one memory including the computer program code are further configured to cause the apparatus to:
use the private key of the base station belonging to the public key of the base station identified by the received key identifier to decrypt the encrypted certificate unit.

10. The apparatus according to claim 9 , wherein the at least one processor and the at least one memory including the computer program code are further configured to cause the apparatus to:
retrieve a nonce from the certificate unit; and at least one of
protect a downlink message to t

Assignees

• Nokia Technologies Oy

Inventors

• Schneider Peter
• Mavureddi Dhanasekaran Ranganathan

Classifications

• H04L9/3263 Primary

  involving certificates, e.g. public key certificate [PKC] or attribute certificate [AC]; Public key infrastructure [PKI] arrangements (network architectures or network communication protocols for supporting authentication of entities using certificates in a packet data network H04L63/0823) · CPC title

• H04W12/06

  Authentication · CPC title

• H04W12/069 Primary

  using certificates or pre-shared keys · CPC title

• H04W12/122

  Counter-measures against attacks; Protection against rogue devices · CPC title

• H04W12/03

  Protecting confidentiality, e.g. by encryption · CPC title