WO2020208294A1

WO2020208294A1 - Establishing secure communication paths to multipath connection server with initial connection over public network

Info

Publication number: WO2020208294A1
Application number: PCT/FI2020/050199
Authority: WO
Inventors: Suresh Nair; Thomas Theimer; Thierry Van De Velde; Satish Kanugovi
Original assignee: Nokia Technologies Oy
Current assignee: Nokia Technologies Oy
Priority date: 2019-04-11
Filing date: 2020-03-27
Publication date: 2020-10-15
Anticipated expiration: 2021-10-11

Abstract

With regard to given user equipment, a method comprises establishing a multipath connectivity security context when registering with a first communication network, wherein the multipath connectivity security context relates to a multipath connection server. The multipath connectivity security context is utilized to establish a first connection with the multipath connection server through the first communication network, and utilized to establish a second connection with the multipath connection server through a second communication network. The first communication network comprises a wireless public network (e.g., 3GPP network) and the second communication network comprises a wireless private network (e.g., non 3GPP network).

Description

ESTABLISHING SECURE COMMUNICATION PATHS TO MULTIPATH CONNECTION SERVER WITH INITIAL CONNECTION OVER PUBLIC

NETWORK

Field

The field relates generally to communication systems, and more particularly, but not exclusively, to security management within such systems.

Background

This section introduces aspects that may be helpful to facilitate a better understanding of the inventions. Accordingly, the statements of this section are to be read in this light and are not to be understood as admissions about what is in the prior art or what is not in the prior art.

Fourth generation (4G) wireless mobile telecommunications technology, also known as Long Term Evolution (LTE) technology, was designed to provide high capacity mobile multimedia with high data rates particularly for human interaction. Next generation or fifth generation (5G) technology is intended to be used not only for human interaction, but also for machine type communications in so-called Internet of Things (IoT) networks.

While 5G networks are intended to enable massive IoT services (e.g., very large numbers of limited capacity devices) and mission-critical IoT services (e.g., requiring high reliability), improvements over legacy mobile communication services are supported in the form of enhanced mobile broadband (eMBB) services providing improved wireless Internet access for mobile devices.

In an example communication system, user equipment (5G UE in a 5G network or, more broadly, a UE) such as a mobile terminal (subscriber) communicates over an air interface with a base station or access point referred to as a gNB in a 5G network. The access point (e.g., gNB) is illustratively part of an access network of the communication system. For example, in a 5G network, the access network is referred to as a 5G System and is described in 5G Technical Specification (TS) 23.501, V15.4.0, entitled “Technical Specification Group Services and System Aspects; System Architecture for the 5G System,” the disclosure of which is incorporated by reference herein in its entirety. In general, the access point (e.g., gNB) provides access for the UE to a core network (CN), which then provides access for the UE to other UEs and/or a data network such as a packet data network (e.g., Internet).

TS 23.501 goes on to define a 5G Service-Based Architecture (SBA) which models services as network functions (NFs) that communicate with each other using representational state transfer application programming interfaces (Restful APIs).

Furthermore, 5G Technical Specification (TS) 33.501, V15.3.1, entitled“Technical Specification Group Services and System Aspects; Security Architecture and Procedures for the 5G System,” the disclosure of which is incorporated by reference herein in its entirety, further describes security management details associated with a 5G network.

Still further, a multiple access management service (MAMS) is proposed for 5G networks. In such a service, it is intended that a UE be able to access a multipath connection server via multiple independent communications networks. However, security management in the context of such multipath connectivity presents several challenges.

Summary

Illustrative embodiments provide improved techniques for security management in communication systems particularly with respect to multipath connectivity.

For example, in one illustrative embodiment in accordance with given user equipment, a method comprises establishing a multipath connectivity security context when registering with a first communication network, wherein the multipath connectivity security context relates to a multipath connection server. The multipath connectivity security context is utilized to establish a first connection with the multipath connection server through the first communication network, and utilized to establish a second connection with the multipath connection server through a second communication network. The first communication network comprises a wireless public network (e.g., 3GPP network) and the second communication network comprises a wireless private network (e.g., non 3GPP network).

In a further embodiment in accordance with a network function of a communication network, a method comprises receiving a multipath connection cryptographic key request from a multipath connection server, wherein the multipath connection cryptographic key request comprises an identifier for given user equipment, an identifier for a multipath connection server, and an identifier for an enterprise cryptographic key. An authentication information request is sent with the identifier for the given user equipment to an authentication function, and an authentication information response is received from the authentication function. A multipath connection cryptographic key is generated based at least in part on information in the authentication information response, and sent to the multipath connection server. In one embodiment, the network function is a network exposure function of the first communication network.

In a yet another embodiment in accordance with a multipath connection server, a method comprises receiving a first session establishment request from given user equipment through a first communication network, wherein the first session establishment request comprises information identifying a multipath connectivity security context established between the given user equipment and the first communication network. The given user equipment is verified using at least part of the security context, and a first connection is established with the given user equipment through the first communication network. Then, a second session establishment request is received from the given user equipment through a second communication network, wherein the second session establishment request comprises information identifying the multipath connectivity security context established between the given user equipment and the first communication network. The given user equipment is verified using at least part of the security context, and a second connection is established with the given user equipment through the second communication network. The first communication network comprises a wireless public network (e.g., 3GPP network) and the second communication network comprises a wireless private network (e.g., non 3GPP network). Further, in one or more illustrative embodiments, the multipath connection server is able to establish more connections to user equipment over available communication networks as needed.

Further illustrative embodiments are provided in the form of a non-transitory computer-readable storage medium having embodied therein executable program code that when executed by a processor causes the processor to perform the above steps. Still further illustrative embodiments comprise apparatus with a processor and a memory configured to perform the above steps.

These and other features and advantages of embodiments described herein will become more apparent from the accompanying drawings and the following detailed description. Brief Description of the Drawings

FIG. 1 illustrates a communication system with which one or more illustrative embodiments are implemented.

FIG. 2 illustrates processing architectures for security management participants, according to an illustrative embodiment.

FIG. 3 illustrates multipath connectivity scenarios, according to an illustrative embodiment.

FIG. 4 illustrates network functions of a communication system associated with secure communications between user equipment and a multipath connection server, according to an illustrative embodiment.

FIG. 5 illustrates a security management methodology for an initial connection with a multipath connection server, according to an illustrative embodiment.

FIG. 6 illustrates a security management methodology for a subsequent connection with a multipath connection server, according to an illustrative embodiment.

FIG. 7 illustrates a security management methodology for an initial connection with a multipath connection server, according to another illustrative embodiment.

Detailed Description

Embodiments will be illustrated herein in conjunction with example communication systems and associated techniques for providing security management (e.g., cryptographic key management) in communication systems. It should be understood, however, that the scope of the claims is not limited to particular types of communication systems and/or processes disclosed. Embodiments can be implemented in a wide variety of other types of communication systems, using alternative processes and operations. For example, although illustrated in the context of wireless cellular systems utilizing 3 GPP system elements such as a 3GPP next generation system (5G), the disclosed embodiments can be adapted in a straightforward manner to a variety of other types of communication systems.

In accordance with illustrative embodiments implemented in a 5G communication system environment, one or more 3 GPP technical specifications (TS) and technical reports (TR) provide further explanation of user equipment and network elements/functions and/or operations that interact with one or more illustrative embodiments, e.g., the above-referenced 3GPP TS 23.501 and 3GPP TS 33.501. Other 3GPP TS/TR documents provide other conventional details that one of ordinary skill in the art will realize. However, while illustrative embodiments are well-suited for implementation associated with the above- mentioned 5G-related 3GPP standards, alternative embodiments are not necessarily intended to be limited to any particular standards.

Furthermore, illustrative embodiments may be explained herein in the context of the Open Systems Interconnection model (OSI model) which is a model that conceptually characterizes communication functions of a communication system such as, for example, a 5G network. The OSI model is typically conceptualized as a hierarchical stack with a given layer serving the layer above and being served by the layer below. Typically, the OSI model comprises seven layers with the top layer of the stack being the application layer (layer 7) followed by the presentation layer (layer 6), the session layer (layer 5), the transport layer (layer 4), the network layer (layer 3), the data link layer (layer 2), and the physical layer (layer 1). One of ordinary skill in the art will appreciate the functions and interworkings of the various layers and, thus, further details of each layer are not described herein. However, it is to be appreciated that while illustrative embodiments are well-suited for implementations that utilize an OSI model, alternative embodiments are not necessarily limited to any particular communication function model.

Illustrative embodiments are related to security management associated with the Service-Based Architecture (SBA) for 5G networks. Prior to describing such illustrative embodiments, a general description of main components of a 5G network will be described below in the context of FIGS. 1 and 2.

FIG. 1 shows a communication system 100 within which illustrative embodiments are implemented. It is to be understood that the elements shown in communication system 100 are intended to represent main functions provided within the system, e.g., UE access functions, mobility management functions, authentication functions, serving gateway functions, etc. As such, the blocks shown in FIG. 1 reference specific elements in 5G networks that provide these main functions. However, other network elements may be used in other embodiments to implement some or all of the main functions represented. Also, it is to be understood that not all functions of a 5G network are depicted in FIG. 1. Rather, functions that facilitate an explanation of illustrative embodiments are represented. Subsequent figures may depict some additional elements/functions. Accordingly, as shown, communication system 100 comprises user equipment (UE) 102 that communicates via an air interface 103 with an access point (gNB) 104. The UE 102 in some embodiments is a mobile station, and such a mobile station may comprise, by way of example, a mobile telephone, a computer, or any other type of communication device. The term“user equipment” as used herein is therefore intended to be construed broadly, so as to encompass a variety of different types of mobile stations, subscriber stations or, more generally, communication devices, including examples such as a combination of a data card inserted in a laptop or other equipment such as a smart phone or other cellular device. In one or more illustrative embodiments, user equipment refers to an IoT device. Such communication devices are also intended to encompass devices commonly referred to as access terminals.

In one embodiment, UE 102 is comprised of a Universal Integrated Circuit Card (UICC) part and a Mobile Equipment (ME) part. The UICC is the user-dependent part of the UE and contains at least one Universal Subscriber Identity Module (USIM) and appropriate application software. The USIM securely stores the permanent subscription identifier and its related key, which are used to identify and authenticate subscribers to access networks. The ME is the user-independent part of the UE and contains terminal equipment (TE) functions and various mobile termination (MT) functions.

Note that, in one example, the permanent subscription identifier is an International Mobile Subscriber Identity (IMSI) of a UE. In one embodiment, the IMSI is a fixed 15-digit length and consists of a 3-digit Mobile Country Code (MCC), a 3-digit Mobile Network Code (MNC), and a 9-digit Mobile Station Identification Number (MSIN). In a 5G communication system, an IMSI is referred to as a Subscription Permanent Identifier (SUPI). In the case of an IMSI as a SUPI, the MSIN provides the subscriber identity. Thus, only the MSIN portion of the IMSI typically needs to be encrypted. The MNC and MCC portions of the IMSI provide routing information, used by the serving network to route to the correct home network. When the MSIN of a SUPI is encrypted, it is referred to as a Subscription Concealed Identifier (SUCI).

The access point 104 is illustratively part of an access network of the communication system 100. Such an access network comprises, for example, a 5G System having a plurality of base stations and one or more associated radio network control functions. The base stations and radio network control functions in some embodiments are logically separate entities, but in some embodiments are implemented in the same physical network element, such as, for example, a base station router or cellular access point.

The access point 104 in this illustrative embodiment is operatively coupled to mobility management functions 106. In a 5G network, the mobility management function is implemented by an Access and Mobility Management Function (AMF). A Security Anchor Function (SEAF) in some embodiments is also implemented with the AMF connecting a UE with the mobility management function. A mobility management function, as used herein, is the element or function (i.e., entity) in the core network (CN) part of the communication system that manages or otherwise participates in, among other network operations, access and mobility (including authentication/authorization) operations with the UE (through the access point 104). The AMF is also referred to herein, more generally, as an access and mobility management entity.

The AMF 106 in this illustrative embodiment is operatively coupled to home subscriber functions 108, i.e., one or more functions that are resident in the home network of the subscriber. As shown, some of these functions include the Unified Data Management (UDM) function, as well as an Authentication Server Function (AUSF). The AUSF and UDM (separately or collectively) are also referred to herein, more generally, as an authentication entity. In addition, home subscriber functions include, but are not limited to, Network Slice Selection Function (NSSF), Network Exposure Function (NEF), Network Repository Function (NRF), and Policy Control Function (PCF).

Some of these functions will be further described herein in the context of security management with an application function that, in some illustrative embodiments, runs on an application server associated with a third party. By“third party” here, it is meant to refer to a party other than the subscriber of the UE or the operator of the core network. For example, in one or more illustrative embodiments, the third party is an enterprise (e.g., corporation, business, group, individual, or the like). In some embodiments, the subscriber of the UE is an employee of the enterprise (or otherwise affiliated) who maintains a mobile subscription with the operator of the core network or another mobile network. Note that a UE is typically subscribed to what is referred to as a Home Public Fand Mobile Network (HPFMN) in which some or all of the home subscriber functions 108 reside. If the UE is roaming (not in the HPFMN), it is typically connected with a Visited Public Fand Mobile Network (VPFMN) also referred to as a serving network. Some or all of the mobility management functions 106 may reside in the VPLMN, in which case, functions in the VPLMN communicate with functions in the HPLMN as needed. However, in a non-roaming scenario, mobility management functions 106 and home subscriber functions 108 can reside in the same communication network.

Note that the application function is a multipath connection server in illustrative embodiments. In some embodiments, the multipath connection server is associated with a third party, such as an enterprise as illustratively mentioned above.

The access point 104 is also operatively coupled to a serving gateway function, i.e., Session Management Function (SMF) 110, which is operatively coupled to a User Plane Function (UPF) 112. UPF 112 is operatively coupled to a Packet Data Network, e.g., Internet 114. As is known in 5G and other communication networks, the user plane (UP) or data plane carries network user traffic while the control plane (CP) carries signaling traffic. SMF 110 supports functionalities relating to UP subscriber sessions, e.g., establishment, modification and release of PDU sessions. UPF 112 supports functionalities to facilitate UP operations, e.g., packet routing and forwarding, interconnection to the data network (e.g., 114 in FIG. 1), policy enforcement, and data buffering.

It is to be appreciated that FIG. 1 is a simplified illustration in that not all communication links and connections between network functions (NFs) and other system elements are illustrated in FIG. 1. One ordinarily skilled in the art given the various 3 GPP TSs/TRs will appreciate the various links and connections not expressly shown or that may otherwise be generalized in FIG. 1.

Further typical operations and functions of certain network elements are not described herein in detail when they are not the focus of illustrative embodiments but can be found in appropriate 3GPP 5G documentation. It is to be appreciated that the particular arrangement of system elements in FIG. 1 is an example only, and other types and arrangements of additional or alternative elements can be used to implement a communication system in other embodiments. For example, in other embodiments, the system 100 comprises other elements/functions not expressly shown herein. Also, although only single elements/functions are shown in the FIG. 1 embodiment, this is for simplicity and clarity of illustration only. A given alternative embodiment may include larger numbers of such system elements, as well as additional or alternative elements of a type commonly associated with conventional system implementations. It is also to be noted that while FIG. 1 illustrates system elements as singular functional blocks, the various subnetworks that make up the 5G network are partitioned into so-called network slices. Network slices (network partitions) comprise a series of network function (NF) sets (i.e., function chains) for each corresponding service type using network function virtualization (NFV) on a common physical infrastructure. The network slices are instantiated as needed for a given service, e.g., eMBB service, massive IoT service, and mission-critical IoT service. A network slice or function is thus instantiated when an instance of that network slice or function is created. In some embodiments, this involves installing or otherwise running the network slice or function on one or more host devices of the underlying physical infrastructure. UE 102 is configured to access one or more of these services via gNB 104. NFs can also access services of other NFs.

Illustrative embodiments provide a security management methodology for multipath connectivity where a multipath connectivity security context is established for a given UE and used when connecting with a multipath connection server. The term“security context” is understood to refer to any information relating to the establishment and maintenance of security of communications between two or more participants. By way of example only, a security context can comprise one or more identities and/or one or more keys or key materials (e.g., generated, derived, or otherwise obtained). Note that when the term“key” is used alone, it is understood to refer to a cryptographic key.

FIG. 2 is a block diagram of processing architectures 200 of participants in a security management methodology for multipath connectivity in an illustrative embodiment. As will be further explained below, more than two participants are involved in security management according to illustrative embodiments, e.g., UE, AMF, NEF, UDM, SMF, non 3GPP elements. As such, FIG. 2 illustrates processing architectures associated with any two of the participants that directly or indirectly communicate. Therefore, in illustrative embodiments, each participant in a security management methodology is understood to be configured with the processing architecture shown in FIG. 2.

As shown, a first security management participant 202 comprises a processor 212 coupled to a memory 216 and interface circuitry 210. The processor 212 of the first security management participant 202 includes a security management processing module 214 that may be implemented at least in part in the form of software executed by the processor. The processing module 214 performs security management described in conjunction with subsequent figures and otherwise herein. The memory 216 of the first security management participant 202 includes a security management storage module 218 that stores data generated or otherwise used during security management operations.

As further shown, a second security management participant 204 comprises a processor 222 coupled to a memory 226 and interface circuitry 220. The processor 222 of the second security management participant 204 includes a security management processing module 224 that may be implemented at least in part in the form of software executed by the processor 222. The processing module 224 performs security management described in conjunction with subsequent figures and otherwise herein. The memory 226 of the second security management participant 204 includes a security management storage module 228 that stores data generated or otherwise used during security management operations.

The processors 212 and 222 of the respective security management participants 202 and 204 may comprise, for example, microprocessors, application-specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), digital signal processors (DSPs) or other types of processing devices or integrated circuits, as well as portions or combinations of such elements. Such integrated circuit devices, as well as portions or combinations thereof, are examples of“circuitry” as that term is used herein. A wide variety of other arrangements of hardware and associated software or firmware may be used in implementing the illustrative embodiments.

The memories 216 and 226 of the respective security management participants 202 and 204 may be used to store one or more software programs that are executed by the respective processors 212 and 222 to implement at least a portion of the functionality described herein. For example, security management operations and other functionality as described in conjunction with subsequent figures and otherwise herein may be implemented in a straightforward manner using software code executed by processors 212 and 222.

A given one of the memories 216 or 226 may therefore be viewed as an example of what is more generally referred to herein as a computer program product or still more generally as a processor-readable storage medium that has executable program code embodied therein. Other examples of processor-readable storage media may include disks or other types of magnetic or optical media, in any combination. Illustrative embodiments can include articles of manufacture comprising such computer program products or other processor-readable storage media. The memory 216 or 226 may more particularly comprise, for example, an electronic random-access memory (RAM) such as static RAM (SRAM), dynamic RAM (DRAM) or other types of volatile or non-volatile electronic memory. The latter may include, for example, non-volatile memories such as flash memory, magnetic RAM (MRAM), phase- change RAM (PC-RAM) or ferroelectric RAM (FRAM). The term“memory” as used herein is intended to be broadly construed, and may additionally or alternatively encompass, for example, a read-only memory (ROM), a disk-based memory, or other type of storage device, as well as portions or combinations of such devices.

The interface circuitries 210 and 220 of the respective security management participants 202 and 204 illustratively comprise transceivers or other communication hardware or firmware that allows the associated system elements to communicate with one another in the manner described herein.

It is apparent from FIG. 2 that first security management participant 202 is configured for communication with the second security management participant 204 and vice-versa via their respective interface circuitries 210 and 220. This communication involves the first security management participant 202 sending data to the second security management participant 204, and the second security management participant 204 sending data to the first security management participant 202. However, in alternative embodiments, other network elements or other components may be operatively coupled between, as well as to, the security management participants 202 and 204. The term“data” as used herein is intended to be construed broadly, so as to encompass any type of information that may be sent between security management participants including, but not limited to, messages, tokens, identifiers, keys, indicators, user data, control data, etc.

It is to be appreciated that the particular arrangement of components shown in FIG. 2 is an example only, and numerous alternative configurations are used in other embodiments. For example, any given network element/function can be configured to incorporate additional or alternative components and to support other communication protocols.

Given the above illustrative architectures, illustrative embodiments of security management methodologies for multipath connectivity functionalities will be further described below. Prior to such descriptions, some main considerations that at least partially motivated development of illustrative embodiments will be described in the context of a 5G network (as an example of a 3 GPP or wireless public network) and a wireless local area network or WLAN (as an example of a non 3 GPP or wireless private network).

FIG. 3 illustrates a multipath connectivity scenario 300, according to an illustrative embodiment. As mentioned above, multipath connectivity functionality (e.g., MAMS) is intended to provide multipath connections consistent with a 5G network environment. More particularly, as shown in FIG. 3, UE 302 is connected to a multipath connection server 304 over a 5G core network 306 and over a non 3 GPP access such as a private network, e.g., WLAN 308. Multipath connection server 304 functions as a multipath connectivity proxy (e.g., a network function in the context of a 5G network), which can be accessed over multiple independent networks (e.g., two networks in the FIG. 3 embodiments but which can be more than two independent networks in other embodiments).

However, secure establishment of multipath connections to a multipath connectivity proxy (e.g., multipath connection server 304) across independent networks (e.g., 5G core network 306 and WLAN 308) presents challenges.

Multipath protocol procedures, e.g., MPTCP, may require the client to establish a multipath session when the initial access network connection is established, i.e. even when the device starts with a single access network connection. Lor example, assume an IoT scenario that involves IoT devices in a factory setting, e.g., robotic devices operating on a factory floor that are also configured as UEs. When a robotic device connects via 5G, it has to setup the first leg of a multipath connection with the multipath connectivity function in the network. Later, when the robotic device connects via WLAN, it establishes the second multipath leg to the same multipath connectivity function. Since, the robotic devices perform critical functions in the factory, often in cooperation with other robotic devices and other types of devices in the factory network, it is important to ensure a secured connection. Irrespective of the varied level of security offered by the underlying access network connections, it is realized herein that unauthorized users should not be able to establish new multipath sessions or break into existing multipath sessions.

Lurthermore, it is realized herein that the network should control which devices are authorized to establish the initial multipath session and also ensure that the second leg establishment, from an independent network, is indeed from the originator of the first leg. In other words, it is further realized herein that a device should assert its identity of the multipath session. In illustrative embodiments, this is ensured by exchanging a commonly derived key (part of a security context) between the UE (e.g., robotic or other IoT device) and the multipath connectivity function during establishment of initial and subsequent legs, which cannot be carried across multipath sessions.

More particularly, in illustrative embodiments, the UE that wants to establish a multipath connection connects to the 5G network. The UE accesses the 5G network with its 5G network subscription identity SUPI and undergoes 5G authentication procedures. At the end of a successful authentication, the UE and the network authenticate each other and establish a connection.

During the authentication, when the UE sends the 5G subscription identifier SUPI (or its encrypted form SUCI), the UDM determines that the UE is also subscribed to a multipath connection server. Thus, in addition to the regular 5G authentication vectors (AVs) for 5G access, the UDM instructs the AUSF to generate intermediate keys intended for authenticating exposure to the multipath connection server through the NEF. The NEF generates specific keys for the exposure, in this case, exposing the multipath connection server to the UE. The NEF acts as a security anchor for exposure of network functions (NF) to third party applications and derives the specific keys meant to authenticate any UE that is requesting the NF services.

In the context of illustrative embodiments, where the multipath connection server is an NF, the NEF derives specific authentication keys based on a multipath connection server identity. The NEF may consider the identity of the multipath connection server, such as its Internet Protocol (IP) address, fully qualified domain name (FQDN), server type, etc., while deriving the unique keys. The UE also is expected to know how to derive the key specific for an NF. The UE accesses the multipath connection server over the 5G 3 GPP system first, e.g., over NR (New Radio), subsequent to a successful 5G authentication. Following this, when the UE meets conditions for a second access to the multipath connection server, the second access to the multipath connection server is made over a non 3 GPP network or private network (e.g., WLAN). The UE presents its unique identity and credentials received over the secured 3 GPP network, to the multipath connection server, while registering with it over the non 3 GPP network. The unique identity may include one of a permanent subscription identity (SUPI), device identity IMEI, 3 GPP network IP address, 3 GPP temporary network identity such as serving temporary mobile subscriber identity (STMSI) or globally unique temporary identity (GUTI), or any identity assigned by the multipath connection server over the 3 GPP network.

Illustrative embodiments assume that UE 302 first makes the connection to multipath connection server 304 over 5G core network 306.

Note that the concurrently filed patent application identified by attorney docket number 316567-IN-NP and entitled “Establishing Secure Communication Paths to Multipath Connection Server with Initial Connection Over Private Network,” the disclosure of which is incorporated by reference herein in its entirety, describes multipath connectivity for the scenarios when UE 302 first makes the connection to multipath connection server 304 over a non 3GPP access, i.e., over WLAN 308.

Therefore, using both methods, UE 302 can start the connection over a 3GPP network or over a non 3 GPP network and move around freely without losing the connection with multipath connection server 304.

These and other multipath connection features of illustrative embodiments will be described below in the context of FIGS. 4-7.

NEF functionality is specified in the above-referenced TS 23.501 (e.g., clause 6.2.5).

In illustrative embodiments, the NEF is adapted as a security anchor that provides security management services to a multipath connection (MPC) server. The NEF is responsible for generating MPC-specific key material to be used between the UE and the MPC server and in maintaining an active UE security context. The NEF and its functional environment are depicted in process 400 of FIG. 4 which shows how the NEF acts as a security anchor function for an MPC server (note that the MPC server is considered an NF in illustrative embodiments).

More particularly, FIG. 4 illustrates a 5G Core (CN) 410 with SEAF 412, UDM 414, NEF 416, and AUSF 418. NEF 416 is operatively coupled to UDM 414 and MPC server 420, while UE 430 is operatively coupled to MPC server 420 and AUSF 418.

NEF 416 interfaces with UDM 414 in 5G Core 410 to obtain the required inputs (such as one or more AVs) for generating a UE-specific MPC key (a key specific to UE 330 for MPC server 420). In another embodiment, UDM 414 generates an enterprise key based on UE subscription data, which is then used by NEF 416 to generate an MPC-specific cryptographic key using an MPC identifier as one of the inputs. Furthermore, NEF 416 provides a Service-Based Interface (SBI)-based northbound interface to MPC server 420. Recall that FIG. 3 illustrates a multipath connectivity scenario whereby a UE establishes a first connection with an MPC server through the 5G core (public or 3 GPP) network, followed by a second connection with the MPC server through a private (non 3GPP) network such as a WLAN. As described below, FIGS. 5 and 7 illustrate embodiments of message flows for establishing the first or initial connection, and FIG. 6 illustrates an embodiment of a message flow for establishing the second or subsequent connection.

FIG. 5 illustrates a security management methodology for an initial connection with a multipath connection server, according to an illustrative embodiment. The initial or first connection is with a 3GPP network (e.g., 5G core). More particularly, FIG. 5 depicts an end-to-end message flow 500 between UE 502, AMF 504, multipath connection (MPC) server 506, NEF 508, and UDM 510.

Step 1 (520). UE 502 registers over the 5G 3GPP network and gets authenticated in a typical 5G authentication manner. Access to the 5G Core over a trusted NR interface as well as untrusted Wifi access over N3IWF with 5GC credentials are assumed here.

Step 2 (522). When UE 502 wants to access the MPC server 506, it generates an Enterprise key for general enterprise access using NEF 508 and also a specific MPC server key.

Step 3 (524). UE 502 sends a Session Establishment Request to the MPC server 506 which is considered one of the NFs within the 3GPP network. MPC server 506 is assumed to function as an independent NF in the Service Based Architecture of the 5G core network.

Step 4 (526). MPC server 506 sends an Application Key Request for the UE 502, with the UE ID (identity), and its own MPC server ID, to NEF 508 within the 5G Core.

Step 5 (528). NEF 508 verifies whether an authentication and special key is required to be connected to the MPC server 506.

Step 6 (530). If special authentication is required for connectivity to MPC server 506, NEF 508 sends an Authentication Information Request to UDM 510 with UE ID.

Step 7 (532). UDM 510 generates AVs for authenticating UE 502 by the MPC server 506. UDM 510 sends back Authentication Information Response containing (AVs, and UE ID).

Step 8 (534). From the AVs, NEF 508 generates an Enterprise key for UE 502 and specific MPC server keys to authenticate UE 502. Step 9 (536). NEF 508 sends back Application Key Response to MPC server 506 with the MPC key and validity time (i.e., duration of validity of the key).

Step 10 (538). MPC server 506 generates an MPC key, to be used as a pre-shared key (PSK) for the multipath connectivity to UE 502.

Step 11 (540). MPC server 506 and UE 502 exchange multiple session establishment messages to establish connectivity to MPC server 506. The multiple messages may involve Challenge-Response messages to verify that UE 502 is in possession of the PSK and the authentication key and to verify UE identity.

FIG. 6 illustrates a security management methodology for a subsequent connection (i.e., a connection following the first connection described above in the context of FIG. 5 or below in the context of FIG. 7) with a multipath connection server, according to an illustrative embodiment. More particularly, FIG. 6 shows an end-to-end message flow 600 for establishing a second or subsequent connection to the MPC server over private non 3GPP access, assuming a first connection has been made through a 3 GPP network. The same system elements, i.e., UE 502, AMF 504, MPC server 506, NEF 508, and UDM 510, are shown in FIG. 6.

Step 1 (620). UE 502 registers over the 3GPP network, gets authenticated and establishes UE context with 5G core.

Step 2 (622). UE 502 gets connected over the 3GPP network to the MPC server 506.

Step 3 (624). UE 502 moves around and when conditions are met, registers over a non 3GPP network (private network) to the MPC server 506. The message contains, MPC server ID, UE ID, connection ID, validation credentials etc. received over the 3 GPP network, for the MPC server 506 to determine the correct UE security context. UE 502 uses the MPC server ID to register to the same MPC server it had registered over 3 GPP network. The registration protocol over the non 3 GPP network may be different than the 3 GPP network.

Step 4 (626). MPC server 506 validates UE ID, MPC server ID, and the credentials presented.

Step 5 (628). MPC server 506 may initiate multiple challenge-response messages with UE 502 to verify that the UE is really in possession of the parameters using the keys established over the 3 GPP network. Step 6 (630). At the end of successful authentication, both UE 502 and MPC server 506 establishes connection over the non 3GPP network as well as the 3GPP network (i.e., establishes multipath connectivity).

FIG. 7 illustrates a security management methodology for an initial connection with a multipath connection server, according to another illustrative embodiment. More particularly, FIG. 7 depicts and end-to-end message flow 700 as an alternate embodiment (to the FIG. 5 embodiment) for establishing a primary connection to the MPC server over the 3GPP network using secondary authentication method. The same system elements, i.e., UE 502, AMF 504, MPC server 506 (configured as an external data network or DN) and UDM 510, are shown in FIG. 7, with the addition of SMF 512.

Step 1 (720). UE 502 gets attached to the 3GPP network, and gets authenticated by one of the 3GPP defined primary authentication methods, either 3GPP AKA (RFC 5247) or EAP-AKA’ (RFC 5448) method. AKA stands for Authentication and Key Agreement while EAP stands for Extensible Authentication Protocol.

Step 2 (722). UE 502 decides to establish connection to MPC server 506.

Step 3 (724). UE 502 sends a packet data unit (PDU) session Request to SMF 512 with UE ID and access point name (APN) ID. MPC server 506 is configured with respect to SMF 512 as an APN requiring secondary authentication.

Step 4 (726). SMF 512 triggers secondary authentication as defined in TS 33.501 clause 11.1 for establishing connection between UE 502 and MPC server 506 after verifying that UE 502 has a subscription to MPC server 506.

Step 5 (728). Secondary authentication is performed over the 3GPP network between UE 502 and MPC server 506. The procedure may involve multiple Challenge/Requests as part of the defined EAP procedure.

Step 6 (730). At the end of successful authentication of UE 502, UE 502 is connected to MPC server 506 over the 3 GPP network. UE 502 receives a unique ID and security credentials for subsequent connection establishment over the non 3 GPP network.

Step 7 (732). UE 502 sends second a Connection Request to MPC server 506 over the non 3 GPP network using the UE ID assigned over the 3 GPP network.

Step 8 (734). MPC server 506 authenticates UE 502 using the credentials assigned over the 3 GPP network. Step 9 (736). At the end of successful authentication, UE 502 is connected to MPC server 506 both over the 3 GPP network as well as the non 3 GPP network.

The particular processing operations and other system functionality described in conjunction with the message flow diagrams of FIGS. 5-7 are presented by way of illustrative example only, and should not be construed as limiting the scope of the disclosure in any way. Alternative embodiments can use other types of processing operations and messaging protocols. For example, the ordering of the steps may be varied in other embodiments, or certain steps may be performed at least in part concurrently with one another rather than serially. Also, one or more of the steps may be repeated periodically, or multiple instances of the methods can be performed in parallel with one another.

It should therefore again be emphasized that the various embodiments described herein are presented by way of illustrative example only and should not be construed as limiting the scope of the claims. For example, alternative embodiments can utilize different communication system configurations, user equipment configurations, base station configurations, authentication and key agreement protocols, key pair provisioning and usage processes, messaging protocols and message formats than those described above in the context of the illustrative embodiments. These and numerous other alternative embodiments within the scope of the appended claims will be readily apparent to those skilled in the art.

Claims

I/We Claim:

1. An apparatus comprising:

at least one processor;

at least one memory including computer program code;

the at least one memory and the computer program code being configured to, with the at least one processor, cause the apparatus at least to:

establish a multipath connectivity security context when registering with a first communication network, wherein the multipath connectivity security context relates to a multipath connection server;

utilize the multipath connectivity security context to establish a first connection with the multipath connection server through the first communication network; and

utilize the multipath connectivity security context to establish a second connection with the multipath connection server through a second communication network;

wherein the first communication network comprises a wireless public network and the second communication network comprises a wireless private network.

2. The apparatus of claim 1, wherein establishing the multipath connectivity security context further comprises causing the apparatus to:

generate a cryptographic key when registering with the first communication network, wherein the cryptographic key corresponds to the multipath connection server.

3. The apparatus of claim 2, wherein establishing the multipath connectivity security context further comprises causing the apparatus to:

generate a cryptographic key associated with an entity associated with the multipath connection server.

4. The apparatus of claim 3, wherein utilizing the multipath connectivity security context to establish the first connection further comprises causing the apparatus to:

send a session establishment request to the multipath connection server over the first communication network, wherein the session establishment request comprises an identifier for the multipath connection server cryptographic key, an identifier for the entity cryptographic key, and an identifier for the apparatus.

5. The apparatus of claim 4, wherein utilizing the multipath connectivity security context to establish the first connection further comprises causing the apparatus to:

receive a session establishment response from the multipath connection server.

6. The apparatus of claim 3, wherein utilizing the multipath connectivity security context to establish the first connection further comprises causing the apparatus to:

send a session establishment request to a network function associated with the first communication network, wherein the session establishment request comprises an identifier of an access point name associated with the multipath connection server, and an identifier for the apparatus.

7. The apparatus of claim 6, wherein utilizing the multipath connectivity security context to establish the first connection further comprises causing the apparatus to:

receive a session establishment response from the multipath connection server.

8. The apparatus of claim 3, wherein utilizing the multipath connectivity security context to establish the second connection further comprises causing the apparatus to: send a session establishment request to the multipath connection server over the second communication network, wherein the session establishment request comprises an identifier for the multipath connection server cryptographic key, an identifier for the entity cryptographic key, and an identifier for the apparatus.

9. The apparatus of claim 8, wherein utilizing the multipath connectivity security context to establish the second connection further comprises causing the apparatus to: respond to one or more verification messages and parameters from the multipath connection server over the second communication network.

10. The apparatus of claim 9, wherein utilizing the multipath connectivity security context to establish the second connection further comprises causing the apparatus to: receive a session establishment response from the multipath connection server.

11. A method comprising:

in accordance with given user equipment;

establishing a multipath connectivity security context when registering with a first communication network, wherein the multipath connectivity security context relates to a multipath connection server;

utilizing the multipath connectivity security context to establish a first connection with the multipath connection server through the first communication network; and

utilizing the multipath connectivity security context to establish a second connection with the multipath connection server through a second communication network;

wherein the first communication network comprises a wireless public network and the second communication network comprises a wireless private network;

wherein the given user equipment comprises a processor and memory configured to execute the above steps.

12. An article of manufacture comprising a non-transitory computer-readable storage medium having embodied therein executable program code that when executed by the processor associated with the given user equipment causes the given user equipment to perform the steps of claim 11.

13. An apparatus comprising:

at least one processor;

at least one memory including computer program code;

receive a multipath connection cryptographic key request from a multipath connection server, wherein the multipath connection cryptographic key request comprises an identifier for given user equipment, an identifier for a multipath connection server, and an identifier for an enterprise cryptographic key;

send an authentication information request with the identifier for the given user equipment to an authentication function;

receive an authentication information response from the authentication function; generate a multipath connection cryptographic key based at least in part on information in the authentication information response; and

send the multipath connection cryptographic key to the multipath connection server.

14. The apparatus of claim 13, wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the apparatus at least to execute as a network exposure function for performing the receive, send, receive, generate and send operations.

15. The apparatus of claim 13, wherein the authentication information response comprises an authentication vector corresponding to the given user equipment and the multipath connection cryptographic key is generated based at least in part on the authentication vector.

16. The apparatus of claim 13, wherein the multipath connection cryptographic key is sent to the multipath connection server with an expire time.

17. A method comprising :

in accordance with a network function of a communication network;

receiving a multipath connection cryptographic key request from a multipath connection server, wherein the multipath connection cryptographic key request comprises an identifier for given user equipment, an identifier for a multipath connection server, and an identifier for an enterprise cryptographic key;

sending an authentication information request with the identifier for the given user equipment to an authentication function;

receiving an authentication information response from the authentication function; generating a multipath connection cryptographic key based at least in part on information in the authentication information response; and

sending the multipath connection cryptographic key to the multipath connection server;

wherein the network function is implemented by a processor and memory configured to execute the above steps.

18. An article of manufacture comprising a non-transitory computer-readable storage medium having embodied therein executable program code that when executed by the processor associated with the network function causes the network function to perform the steps of claim 17.

19. An apparatus comprising:

at least one processor;

at least one memory including computer program code;

receive a first session establishment request from given user equipment through a first communication network, wherein the first session establishment request comprises information identifying a multipath connectivity security context established between the given user equipment and the first communication network;

verify the given user equipment using at least part of the security context;

establish a first connection with the given user equipment through the first communication network;

receive a second session establishment request from the given user equipment through a second communication network, wherein the second session establishment request comprises information identifying the multipath connectivity security context established between the given user equipment and the first communication network;

verify the given user equipment using at least part of the security context;

establish a second connection with the given user equipment through the second communication network;

20. The apparatus of claim 19, wherein the first communication network is a 3GPP network, and the second communication network is a non 3 GPP network.

21. The apparatus of claim 19, wherein the apparatus is configured as a network function of the first communication network.

22. The apparatus of claim 19, wherein the apparatus is configured as a data network external to the first communication network.

23. The apparatus of claim 19, wherein the apparatus is part of a multiple access management service.

24. The apparatus of claim 19, wherein verifying the given user equipment for the first connection is performed using one or more authentication vectors obtained from an authentication function of the first communication network.

25. The apparatus of claim 19, wherein verifying the given user equipment for the first connection is performed independent of an authentication function of the first communication network.

26. A method comprising:

in accordance with a multipath connection server;

receiving a first session establishment request from given user equipment through a first communication network, wherein the first session establishment request comprises information identifying a multipath connectivity security context established between the given user equipment and the first communication network;

verifying the given user equipment using at least part of the security context;

establishing a first connection with the given user equipment through the first communication network;

receiving a second session establishment request from the given user equipment through a second communication network, wherein the second session establishment request comprises information identifying the multipath connectivity security context established between the given user equipment and the first communication network;

verifying the given user equipment using at least part of the security context; establishing a second connection with the given user equipment through the second communication network;

wherein the multipath connection server is implemented by a processor and memory configured to execute the above steps.

27. An article of manufacture comprising a non-transitory computer-readable storage medium having embodied therein executable program code that when executed by the processor associated with the multipath connection server causes the multipath connection server to perform the steps of claim 26.