Method and apparatus for ad-hoc communication in mission critical systems (MCX)
According to an embodiment of the present disclosure, a method of key-management by a group management server in Mission Critical Systems (MCX) between an initiating party and a receiving party is provided. The method comprises generating a master key, the master key being designated for an ad-hoc communication, allocating an identifier to the generated master key, and transmitting a transmission message signed by an initiating MCX entity including the master key to a receiving MCX entity.
1. A method of key-management by a group management server in Mission Critical Systems (MCX) between an initiating party and a receiving party, the method comprising:
generating a master key, the master key being designated for an ad-hoc communication;
allocating an identifier to the generated master key; and
transmitting a transmission message signed by an initiating MCX entity including the master key to a receiving MCX entity.
2. The method of claim 1 , wherein the transmission message comprises:
a main payload defined by an encapsulated key defined by encryption of the master key by a user-identity related to the receiving MCX entity; and
an ad-hoc user-key identifier defining an end-point-specific key identity derived from the allocated identifier;
and
wherein an ad-hoc communication invitation is transmitted from a first user equipment to a second user equipment based on:
the master key; or
a key identifier identifying the master key from amongst a plurality of master keys.
3. The method of claim 2 , wherein each of the allocated identifier and the ad-hoc user-key identifier of the master key is a 32-bit key identifier representing the generated master key for the ad-hoc communication and comprises:
a 4 bit purpose-tag; and
a 28 bit random number.
4. The method of claim 2 , wherein the transmission message is a MIKEY-SAKKE I_MESSAGE defined in IETF RFC 6509.
5. The method of claim 4 , wherein the ad-hoc user-key identifier is stored in a CSB-ID field of the MIKEY I_MESSAGE.
6. A group management server for key-management in Mission Critical Systems (MCX) between an initiating party and a receiving party, the group management server comprising:
a processor; and
a memory storing instructions, wherein the instructions, when executed by the processor, cause the processor to:
generate a master key, the master key being designated for an ad-hoc communication;
allocate an identifier to the generated master key; and
transmit a transmission message signed by an initiating MCX entity including the master key to a receiving MCX entity.
7. The group management server of claim 6 , wherein the transmission message comprises:
a main payload defined by an encapsulated key defined by encryption of the master key by a user-identity related to the receiving MCX entity; and
an ad-hoc user-key identifier defining an end-point-specific key identity derived from the allocated identifier; and
wherein an ad-hoc communication invitation is transmitted from a first user equipment to a second user equipment based on:
the master key; or
a key identifier identifying the master key from amongst a plurality of master keys.
8. The group management server of claim 7 , wherein each of the allocated identifier and the ad-hoc user-key identifier of the master key is a 32-bit key identifier representing the generated master key for the ad-hoc communication and comprises:
a 4 bit purpose-tag; and
a 28 bit random number.
9. The group management server of claim 7 , wherein the transmission message is a MIKEY-SAKKE I_MESSAGE defined in IETF RFC 6509.
10. The group management server of claim 9 , wherein the ad-hoc user-key identifier is stored in a CSB-ID field of the MIKEY I_MESSAGE.