Communication method and related product based on key agreement and authentication

A communication method, comprising:

• receiving, by a security anchor function (SEAF), an N1 message from UE, wherein:
• the N1 message carries an encrypted identifier of the UE, the N1 message further carries a Diffie-Hellman (DH) public parameter or a DH public parameter index, and the encrypted identifier is obtained by encrypting a permanent identifier of the UE and a first DH public key;
• and sending, by the SEAF, a first access authentication request to an authentication server function (AUSF), wherein the first access authentication request carries the DH public parameter or the DH public parameter index, and wherein the first access authentication request further caries the encrypted identifier;
• receiving, by the SEAF, a first access authentication response that is used to respond to the first access authentication request and that is sent by the AUSF, wherein the first access authentication response carries a 5G authentication vector and the permanent identifier of the UE, the 5G authentication vector comprises a hashed expected authentication result, and the hashed expected authentication result is derived based on an expected authentication result, the first DH public key, and a second DH public key;
• sending, by the SEAF to the UE, an authentication request carrying a random number;
• and
• receiving, by the SEAF from the UE, an authentication response used to respond to the authentication request, wherein the authentication response carries an authentication result calculated based on a root key and the random number.

User equipment (UE), comprising:

• at least one processor;
• and
• one or more memories coupled to the at least one processor and storing programming instructions for execution by the at least one processor to:
• send an N1 message to a security anchor function (SEAF), wherein:
• the N1 message carries a Diffie-Hellman (DH) public parameter or a DH public parameter index, the N1 message further carries an encrypted identifier of the UE, and the encrypted identifier is obtained by encrypting a permanent identifier of the UE and a first DH public key;
• receive an authentication request that carries a random number and that is sent by the SEAF, wherein the authentication request carries a second DH public key;
• send, to the SEAF, an authentication response used to respond to the authentication request, wherein the authentication response carries an authentication result calculated based on a root key and the random number;
• and
• derive a DH symmetric key based on the DH public parameter and the second DH public key, wherein the UE derives an SEAF key based on the DH symmetric key and an authentication server function (AUSF) key, and the AUSF key is calculated based on the root key and the random number.