Methods, architectures, apparatuses and systems for relay communication security using bootstrapping

A method implemented in a wireless transmit/receive unit (WTRU), the method comprising:

• sending a registration request to a network, wherein the registration request indicates a capability to use relay security with bootstrap keys (RSBK);
• receiving a registration accept from the network, wherein the registration accept indicates an authorization for the WTRU to use RSBK;
• generating an anchor key and an anchor key identifier during a primary authentication procedure;
• deriving a remote user key from at least the anchor key based on the authorization to use RSBK;
• sending a connection request to a relay, wherein the connection request comprises at least the anchor key identifier and a first nonce;
• receiving a security establishment request from the relay, wherein the security establishment request comprises a second nonce;
• and
• deriving a root key to be shared between the WTRU and the relay based on at least the remote user key, the first nonce and the second nonce.

A method implemented in a first network element, the method comprising:

• receiving a key request from a second network element associated with a relay, wherein the key request indicates an anchor key identifier, a first nonce and a relay service code;
• sending a user key request to an anchor function of a wireless transmit/receive unit (WTRU), wherein the user key request indicates the anchor key identifier and the relay service code;
• receiving a user key response from the anchor function of the WTRU, wherein the user key response indicates a remote user key and an identifier of the WTRU;
• deriving a root key to be shared between the WTRU and the relay based on at least the remote user key, the first nonce and a second nonce;
• and
• sending a key response to the second network element associated with the relay, wherein the key response indicates the root key and the second nonce.