Privacy key and message authentication code

A method performed by a user equipment, UE, the method comprising:

• generating a subscription concealed identifier (SUCI) comprising:
• i) an encrypted part in which a Mobile Subscription Identification Number of a subscription permanent identifier (SUPI) is encrypted and ii) a clear-text part comprising:
• a) a Mobile Country Code of the SUPI, b) a Mobile Network Code of the SUPI, c) a public key identifier for a public key of a home network of the user equipment, and d) an encryption scheme identifier that identifies an encryption scheme used by the UE to encrypt the Mobile Subscription Identification Number in the SUCI;
• and
• transmitting, via an Authentication and Mobility management Function (AMF), the SUCI to an authentication server in the home network for forwarding of the SUCI to a de-concealing server capable of decrypting the Mobile Subscription Identification Number.

An authentication server for a home network of a user equipment (UE) for obtaining a subscription permanent identifier (SUPI) comprising a Mobile Subscription Identification Number, a Mobile Country Code, and a Mobile Network Code, the authentication server comprising:

• a receiver for receiving, from the UE via an Authentication and Mobility Management Function (AMF), a message comprising a subscription concealed identifier (SUCI) comprising:
• i) an encrypted part in which the Mobile Subscription Identification Number is encrypted, and ii) a clear-text part comprising:
• a) the Mobile Country Code, b) the Mobile Network Code, c) a public key identifier for a public key of the home network, and d) an encryption scheme identifier that identifies an encryption scheme used by the UE to encrypt the Mobile Subscription Identification Number in the SUCI;
• processing circuitry configured to determine a de-concealing server to use to decrypt the encrypted Mobile Subscription Identification Number;
• and
• a transmitter for sending the SUCI to the de-concealing server.

A user equipment (UE) comprising:

• a transmitter;
• and
• processing circuitry configured to:
• generate a subscription concealed identifier (SUCI) comprising:
• i) an encrypted part in which a Mobile Subscription Identification Number of a subscription permanent identifier (SUPI) is encrypted and ii) a clear-text part comprising:
• a) a Mobile Country Code of the SUPI, b) a Mobile Network Code of the SUPI, c) a public key identifier for a public key of a home network of the UE, and d) an encryption scheme identifier that identifies an encryption scheme used by the UE to encrypt the Mobile Subscription Identification Number in the SUCI;
• and
• employ the transmitter to transmit the SUCI to an authentication server in the home network via an Authentication and Mobility Management Function (AMF).