Secure radio information transfer over mobile radio bearer

Providing secure radio information transfer over a mobile radio bearer by generating one or more secret keys, applying symmetric encryption to unencrypted radio information to generate encrypted radio information, applying a keyed hash operation to the unencrypted radio information using the generated one or more secret keys to generate a message digest, and transmitting both the encrypted radio information and the message digest over a network.

TECHNICAL FIELD

The exemplary and non-limiting embodiments of this invention relate generally to wireless communications and, more specifically, to providing secure radio information transfer over a mobile radio bearer.

BACKGROUND

This section is intended to provide a background or context to the invention disclosed below. The description herein may include concepts that could be pursued, but are not necessarily ones that have been previously implemented, conceived, or described. Therefore, unless otherwise explicitly indicated herein, what is described in this section is not prior art to the description in this application and is not admitted to be prior art by inclusion in this section.

The following abbreviations that may be found in the specification and/or the drawing figures are defined as follows:3DES triple data encryption standard3GPP third generation partnership projectA2 sample receiving applicationAES advanced encryption standardAPN access point nameBTS base transceiver stationCBC cipher-block chainingCN core networkDL downlinkECP extended cyclic prefixE-UTRA evolved universal terrestrial radio accesseNB or eNodeB evolved node B/base station in an E-UTRAN systemEPC evolved packet coreEPS evolved packet systemE-UTRAN evolved UTRAN (LTE)GGSN gateway GPRS support nodeGi interface to external packet data networks (Internet)GPRS general packet radio serviceHE header enrichmentHMAC hash-based message authentication codeID identification, identifierIP internet protocolLTE long term evolutionLTE-A long term evolution advancedMCS modulation and coding schemeMD5 message digest algorithmPDN packet data networkPDP packet data protocolP-GW packet data network gatewayQoS quality of serviceRACS radio application cloud serverRAN radio access networkRF radio frequencyRNC radio network controllerSGSN serving GPRS support nodeS-GW serving gatewaySHA secure hash algorithmSIPTO selected IP traffic offloadSMS short message serviceTCP transport control protocolTOF traffic offloadUE user equipment (e.g. mobile terminal)UL uplinkUMTS universal mobile telecommunications systemUTRAN universal terrestrial radio access network

In the wireless communications industry, traditional design philosophies are based upon building function-specific hardware platforms. This is in contrast to the field of computing where software applications are emphasized far more than the hardware used to run the applications. However, the wireless industry can no longer afford to build dedicated elements that serve singular functions and scale only as far as their allotted capacities. Moreover, conventional design approaches are based upon meeting worst-case scenarios. In practice, these approaches are rather inefficient. A network designed to meet the highest traffic demand during peak hours will have excess unused capacity throughout the remainder of the day.

SUMMARY

Pursuant to a first set of exemplary embodiments of the invention, a method comprises generating one or more secret keys, applying symmetric encryption to unencrypted radio information to generate encrypted radio information, applying a keyed hash operation to the unencrypted radio information using the generated one or more secret keys to generate a message digest, and transmitting both the encrypted radio information and the message digest over a network.

Pursuant to a set of further embodiments of the invention, one or more secret keys are generated by an administrator. Pursuant to a set of further embodiments of the invention, the one or more secret keys are generated by combining a private key of a sender and a public key of a recipient.

Pursuant to a second set of exemplary embodiments of the invention, a method comprises generating one or more secret keys, applying symmetric decryption to received encrypted radio information using the one or more secret keys to generate decrypted radio information, receiving a first message digest, applying a keyed hash operation to the decrypted radio information using the one or more secret keys to generate a second message digest, comparing the first and second message digests, and in response to the first digest being identical to the second digest, verifying that the decrypted radio information is valid.

According to another set of exemplary embodiments of the invention, an apparatus comprises at least one processor and a memory storing a set of computer instructions, in which the processor and the memory storing the computer instructions are configured to cause the apparatus to generate one or more secret keys. Symmetric encryption is applied to unencrypted radio information to generate encrypted radio information. A keyed hash operation is applied to the unencrypted radio information using the generated one or more secret keys to generate a message digest. The encrypted radio information and the message digest are both transmitted over a network.

According to another set of exemplary embodiments of the invention, an apparatus comprises at least one processor and a memory storing a set of computer instructions, in which the processor and the memory storing the computer instructions are configured to cause the apparatus to generate one or more secret keys. Symmetric decryption is applied to received encrypted radio information using the one or more secret keys to generate decrypted radio information. A first message digest is received. A keyed hash operation is applied to the decrypted radio information using the one or more secret keys to generate a second message digest. The first and second message digests are compared. In response to the first digest being identical to the second digest, the decrypted radio information is verified as being valid.

According to another set of exemplary embodiments of the invention, a non-transitory computer readable memory is encoded with a computer program comprising computer readable instructions recorded thereon for execution of a method comprising generating one or more secret keys, applying symmetric encryption to unencrypted radio information to generate encrypted radio information, applying a keyed hash operation to the unencrypted radio information using the generated one or more secret keys to generate a message digest, and transmitting both the encrypted radio information and the message digest over a network.

According to another set of exemplary embodiments of the invention, a non-transitory computer readable memory is encoded with a computer program comprising computer readable instructions recorded thereon for execution of a method comprising generating one or more secret keys, applying symmetric decryption to received encrypted radio information using the one or more secret keys to generate decrypted radio information, receiving a first message digest, applying a keyed hash operation to the decrypted radio information using the one or more secret keys to generate a second message digest, comparing the first and second message digests, and in response to the first digest being identical to the second digest, verifying that the decrypted radio information is valid.

DETAILED DESCRIPTION

A liquid network is a network that is configured for dynamically changing its capacity or purpose as different applications or functions are demanded. Liquid networks shift telecommunications infrastructure away from traditional design philosophies that emphasize a series of purpose-built boxes into a new philosophy in which the network itself becomes a set of applications built on common generic hardware platform. The wireless industry can no longer afford to build dedicated elements that serve singular functions and scale only as far as their maximum capacity will allow. Rather, a dynamic architecture is needed that allocates resources to the applications and functions demanded by the network at any given time or location. Each element, each function has to be able to sense not only the current load it faces, but also the overall health of the network at any given moment. It is highly inefficient to build a network based upon worst-case scenarios. A network designed to meet traffic demands during peak hours may have a substantial amount of unused capacity throughout the remainder of the day. Rather than build base stations and core gateways for these worst-case scenarios, it may be beneficial to provide the network with a set of ‘liquid’ resources which ‘flow’ to wherever these resources are needed, thus allowing operators to design their networks with a fraction of the capacity required under conventional approaches.

A liquid network may be implemented in conjunction with a liquid radio infrastructure designed to turn a traditional mobile network into software-driven network capable of self adapting to network loads. At present, large pools of excess capacity exist in many carrier networks because these networks are built to accommodate peak loads. A liquid radio infrastructure seeks to unfreeze capacity across the radio, core and transport levels. This infrastructure may be configured to enable the network understand the traffic that is moving across it. For example, a liquid radio access network (RAN) architecture incorporates the resource pooling principles laid out in the liquid network approach, removing baseband processing from cell sites and installing this processing in a radio applications cloud server (RACS). As cell sites become more and more congested, baseband resources-flow to the RACS. Baseband resources may continue moving from one RACS to another, following traffic demand through a wireless network.

Instead of replicating standardized hardware elements at every point in the network, liquid networks adopt flexible hardware platforms with application-agnostic processing resources. These flexible hardware platforms are configured to adjust their capacity or purpose in response to a current demand for applications or functions. Processing capacity may be pooled and re-allocated based on the application and location. On the radio side, baseband capacity may be pulled away from a particular cell site and used at another site. In the core, processing can be shared across browsing, VoIP and packet core functionalities. For instance, during a major sporting event, a soccer player achieving a game-changing goal may suddenly produce thousands of mobile requests for a single streamed replay of the goal. A core gateway serving the base stations near the sporting event may be configured to detect significant or critical plays made during the game. In response to detecting the game-changing goal, the core gateway transforms itself into a content delivery network, thereby caching the video near the edge of the network. In this manner, the network dynamically adapts itself to meet a significant but transient demand.

Illustratively, a liquid network may include radio base stations that uses distributed antennae and virtualized baseband processing to provide a highly distributed architecture built around small cells and miniature base-station designs. An evolved packet core (EPC) may be designed in accordance with a common Advanced Telecom Computing Architecture (ATCA). This ATCA platform may support the functions of the entire EPC, along with elements of the IP Multimedia Subsystem (IMS) service delivery network, policy management and specialized functions such as deep packet inspection and content delivery networks. The liquid network May be managed using an end-to-end network management system known as NetAct. NetAct is a self-aware, self-adapting platform that is equipped to reconfigure a liquid network to meet any of a wide variety of demand scenarios in real time.

Liquid networks may, but need not, be employed in connection with a universal terrestrial radio access network (UTRAN) or an evolved UTRAN (E-UTRAN). In the context of 3G, a radio access network (RAN) may be implemented using a base transceiver station (BTS) or a radio network controller (RNC). In the context of long term evolution (LTE), the RAN may be implemented using an evolved Node B (eNB). One or more RACS enable the deployment and hosting of local applications at RAN side in a virtualization computing environment by applying cloud technologies. A “leaky bearer” local breakout concept is applied to gain access to a mobile bearer's IP traffic flows.

LTE has been designed to support packet services in a more efficient manner than universal mobile telecommunications system (UMTS). One basic service, from a wireless data network perspective, is the establishment of a data session that will be used by the mobile device for data services. In UMTS and GPRS, the key to establishing a data session is the Packet Data Protocol (PDP) Context establishment procedure. In LTE, the procedure is somewhat different and is referred to as an Evolved Packet System (EPS) bearer setup.

There are some differences between the EPS bearer setup and the PDP context establishment procedure. In a UMTS network, the data session is established with a PDP Context Activation procedure. But before the PDP context can be established, a user equipment (UE) must perform an Attach procedure. The Attach procedure is used to alert a serving GPRS support node (SGSN) that the UE has powered up. One potential problem with this approach is that there is no action that the UE perform after an Attach without requesting a PDP Context. However, after an Attach, the UE is available to receive a short message service (SMS) message or a Network Initiated PDP Context. The issue is that it is not feasible to perform SMS messaging over a packet network and, in practice, network-initiated PDP context is not performed. Thus, after the Attach procedure is completed, the UE will perform a Primary PDP Context that will establish the data session and allocate an IP address to the UE. This PDP Context will have a quality of service (QoS) associated with it based on the needs specified in a request. If the UE needs to have multiple data sessions due to the existence of a plurality of different required QoS's, the UE will perform a secondary PDP Context activation. Note that there may be other reasons for establishing subsequent PDP Context beyond QoS.

In an LTE-based system, there are two types of data session setups. The first is called a Default EPS Bearer, and the second is called a Dedicated EPS Bearer. The Default EPS Bearer is established as part of the Attach procedure. The Default EPS Bearer will only support a nominal QoS, but that should be sufficient for application signaling. When the UE needs to establish a service, a Dedicated EPS Bearer will be established. This Dedicated EPS Bearer will have the QoS requirements needed for the service. By way of comparison, the LIE Attach/Default EPS Bearer is roughly equivalent to the UMTS Attach followed by a Primary PDP Context establishment procedure. The Secondary PDP Context Activation is similar to the Dedicated EPS Bearer Setup procedure. If one were to look at the key parameters in these messages, one would see that both the UMTS procedures and the LTE procedures still use parameters like an Access Point Name (APN), an IP address type, and QoS parameters. However, an optimization has been implemented in LTE that reduces the number of signaling Messages that need to be sent over the air.

Local breakout scenarios were studied in the third generation partnership project (3 GPP) as part of Release 10 under the name SIPTO (selected IP traffic offload). Results of these scenarios were documented in TR 23.829. One of the concepts is the so-called “leaky bearer” traffic flow break-out, also called TOF (Traffic offload). TOF allows extracting, modifying or inserting IP flows of an existing mobile bearer. This is a flexible break-out concept without involvement of or impact on the UE. TOF provides local access to mobile bearer traffic flows and enables the deployment and execution of applications at the RAN such as header enrichment, content delivery network (CDN) solutions, content delivery optimization, caching solutions, or others. These local applications may benefit from proximity to the radio (e.g., location awareness, lower latency), and by having access to radio information (e.g., radio cell load, location, UE's specific radio condition).

FIG. 1illustrates a block diagram of an exemplary system in which the instant invention may be used. The system architecture shows N user equipments (UEs)110-1through110-N communicating via a corresponding wireless connection105-1through105-N (including uplink and downlink) to a network100. The network100includes an evolved Node B (eNB)/RNC120, an RACS130, and an evolved packet core (EPC)/Core Network (CN)135. The EPC/CN135includes a serving gateway (S-GW)/serving GPRS support node (SGSN)140and a packet data network gateway (P-GW)/gateway GPRS support node (GGSN)150. Pursuant to an E-UTRAN embodiment, the eNB/RNC120is implemented as an eNB and the EPC/CN135is implemented as an EPC. The EPC/CN135includes the S-GW/SSGN140and the P-GW/GGSN150. The S-GW/SGSN140is implemented as an S-GW, and the P-GW/GGSN150is implemented as a P-GW. E-UTRAN is also called long term evolution (LTE).

Pursuant to a UTRAN embodiment, the eNB/RNC120is implemented as an RNC, and the EPC/CN135is implemented as a CN. The EPC/CN135includes the S-GW/SSGN140and the P-GW/GGSN150. The S-GW/SGSN140is implemented as an SGSN, and the P-GW/GGSN150is implemented as a GGSN. The foregoing E-UTRAN and UTRAN examples indicate some possible elements within the network100but are not exhaustive, nor are the shown elements necessary for the particular embodiments. Furthermore, the instant invention may be used in other systems, such as CDMA (code division multiple access) and LTE-A (LTE-advanced).

When the “leaky bearer” concept is applied to either the E-UTRAN embodiment or the UTRAN embodiment of the network100, the RACS130functions as an offload node that is placed between the eNB/RNC120and the EPC/CN135on an Si interface (E-UTRAN) or an Iu-PS interface (UTRAN). The RACS130functions as an offload node that “drills” into E-UTRAN radio access bearers (E-RAB) or UTRAN radio access bearers (RAB). The E-RAB transports the packets of the EPS bearer (discussed previously) between the UE110-1and the EPC/CN135. When an E-RAB exists, there is a one-to-one mapping between this E-RAB and an EPS bearer. A data radio bearer transports the packets of the EPS bearer between the UE110-1and the eNB/RNC120. When a data radio bearer exists, there is a one-to-one mapping between this data radio bearer and the EPS bearer/E-RAB. In the E-UTRAN embodiment of network100, an Si bearer transports the packets of an E-RAB between the eNB/RNC120and the S-GW/SGSN140.

Pursuant to a set of illustrative embodiments of the present invention, a modified pass-through application is performed where an application A1155residing in the RACS130node modifies uplink traffic by “enriching” it. This application A1155may be configured to perform a procedure called “Header Enrichment” (HE). HE conveys radio condition information to applications located in the EPC/CN135. Examples of possible radio information include, but are not limited to, a Cell ID indicator, a′Cell Load indicator, a Radio Link Quality indicator, or bandwidth guidance. This information may be transferred “in-band” within a mobile bearer as part of an options field of TCP headers of applicable IP flows flowing from the UE110-1towards the EPC/CN135. A sample receiving application A2160is a content optimizer which can use the received radio information to improve its algorithms. According to a further set of illustrative embodiments of the present invention, cryptography techniques may be employed to ensure integrity, authenticity, and confidentiality of the information added by the HE process.

Transfer of radio information to applications (in the EPC/CN135and beyond) raises several issues and concerns. Some of the transferred information may be operator-sensitive or business-sensitive or both. How is it possible to ensure that radio information can only be processed by authorized applications? When radio information is transferred to applications, it would be desirable to confirm that the information was not tampered with by unauthorized software or equipment during the transfer. For example, malicious software code within an operator's EPC/CN135may modify the radio information. Ideally, only operator-authorized applications as well as operator-provided Lawful Interception Gateways should be able to process the transferred radio information. In the illustrative embodiment ofFIG. 1, a lawful interception point may be located between applications A1155and A2160, illustratively as integrated function of the P-GW/GGSN150, or on a Gi interface between the P-GW/GGSN150and application A2160.

Another issue with respect to the transfer of radio information is how to confirm that the radio information was, indeed, generated by the application A1155in the RACS130. Due to the fact that the transfer of radio information is performed in-band, a malicious user equipment may attempt to transfer invalid radio information. From a lawful interception/regulation perspective, it is necessary to differentiate between data sent by a user and data modified by a network. It would be desirable to address all of the foregoing issues without requiring separate signaling/control plane mechanisms to convey the radio information to the application A2160.

FIG. 2is a flowchart illustrating a first method, and a result of execution by one or more processors of a set of computer program instructions embodied on a computer readable memory, for providing secure radio information transfer over a mobile radio bearer in accordance with a set of exemplary embodiments of the invention. It is noted that the order of steps shown inFIG. 2is not absolutely required, so in principle, the various steps may be performed out of the illustrated order. Also, certain steps may be skipped, different steps may be added or substituted, or selected steps or groups of steps may be performed in a separate application.

The operational sequence ofFIG. 2commences at block201where one or more secret keys are generated. These one or more secret keys may, but need not, be generated by an administrator. These one or more secret keys may, but need not, be generated by combining a private key of a sender and a public key of a recipient. Next, at block203, symmetric encryption is applied to unencrypted radio information to generate encrypted radio information. The operational sequence progresses to block205where a keyed hash operation is applied to the unencrypted radio information using the generated one or more secret keys to generate a message digest. At block207, the encrypted radio information and the message digest are both transmitted over a network such as network100(FIG. 1).

FIG. 3is a flowchart illustrating a second method, and a result of execution by one or more processors of a set of computer program instructions embodied on a computer readable memory, for providing secure radio information transfer over a mobile radio bearer in accordance with a set of exemplary embodiments of the invention. It is noted that the order of steps shown inFIG. 3is not absolutely required, so in principle, the various steps may be performed out of the illustrated order. Also, certain steps may be skipped, different steps may be added or substituted, or selected steps or groups of steps may be performed in a separate application.

The operational sequence ofFIG. 3commences at block301where one or more secret keys are generated. These one or more secret keys may, but need not, be generated by an administrator. These one or more secret keys may, but need not, be generated by combining a private key of a sender and a public key of a recipient. Next, at block303, symmetric decryption is applied to received encrypted radio information using the one or more secret keys to generate decrypted radio information. The operational sequence progresses to block305where a first message digest is received. A keyed hash operation is applied to the decrypted radio information using the one or more secret keys to generate a second message digest (block307). The first and second message digests are compared (block309). In response to the first digest being identical to the second digest, the decrypted radio information is verified as being valid (block311).

The methods described in connection withFIGS. 2 and 3provide confidentiality, integrity, and authenticity. Confidentiality is provided in the sense that transferred radio, information is protected from unauthorized processing due to the information being encrypted. Thus, only authorized receivers will possess the required secret keys. Integrity is provided due to the fact that the transferred radio information is protected from tampering. A receiver can easily confirm that the received information has been tampered with or determined to be invalid and reject such information. Authenticity is provided in the sense that a receiver of radio information may confirm that the information was sent by valid sender. Only authorized senders will possess the required secret keys.

Symmetric encryption/decryption algorithms may be used in conjunction with either or both of the methods ofFIGS. 2 and 3. These symmetric encryption/decryption algorithms may, but need not, include any of triple data encryption standard (3DES), advanced encryption standard (AES), or Two fish. These symmetric encryption/decryption algorithms may, but need not, provide a cipher mode of operation such as cipher block chaining (CBC). The selection of algorithm, cipher mode operation and key lengths may, but need not, be configurable. Either or both of the methods ofFIGS. 2 and 3may, but need not, utilize message authentication code algorithms such as hash-based message authentication code (HMAC)-message digest algorithm (MD5), or I-MAC-secure hash algorithm (SHA). The selection of algorithm and key lengths may, but need not, be configurable.

While sending the encrypted information and the message digest, the operational sequences ofFIGS. 2 and 3may consider the maximum space and available space in any of the various components of the network100(FIG. 1) to make adjustments as follows. For example, if a transport control protocol (TCP) options header has a maximum 40-byte space available, other use cases or applications may be utilizing a portion of this 40-byte space, so the actual available space may be less than 40 bytes. Since the minimum block size of most symmetric encryption/decryption algorithms is 8 bytes, then the minimum information size is 8 bytes. Likewise, since the minimum block size of message authentication code algorithms is 16 bytes, then the minimum message digest size is 16 bytes. The foregoing limitations imply that a minimum of 24 bytes (8+16) are required for the transfer of radio information.

FIG. 4is a flowchart illustrating a third method, and a result of execution by one or more processors of a set of computer program instructions embodied on a computer readable memory, for sending and receiving radio information in accordance with a set of exemplary embodiments of the invention. It is noted that the order of steps shown inFIG. 4is not absolutely required, so in principle, the various steps may be performed out of the illustrated order. Also, certain steps may be skipped, different steps may be added or substituted, or selected steps or groups of steps may be performed in a separate application.

With reference toFIG. 4, on a sending side410, radio information401is encrypted403using a secret key405to generate encrypted information407. A keyed hash409is applied to the radio information401using the secret key405to generate a message digest411. At the receiving side420, encrypted information415is received and decrypted417using a secret key419to generate radio information421. A keyed hash423is applied, using the secret key492, to the generated radio information421to generate a calculated digest425. The calculated digest425is compared490to a received message digest427.

FIG. 5is a flowchart illustrating a fourth method, and a result of execution by one or more processors of a set of computer program instructions embodied on a computer readable memory, by which a sender and a receiver can create a common secret key without any online communication in accordance with a set of exemplary embodiments of the invention. It is noted that the order of steps shown inFIG. 5is not absolutely required, so in principle, the various steps may be performed out of the illustrated order. Also, certain steps may be skipped, different steps may be added or substituted, or selected steps or groups of steps may be performed in a separate application.

With reference toFIG. 5, on a sending side510, a sender private key501and a receiver public key503are combined505to generate a secret key507. On a receiving side520, a sender public key509and a receiver private key511are combined513to generate a secret key515. Note that the sender and the receiver need to possess the other party's public key. With regard to key management, a sender may support multiple receivers (& vice versa). Administrative support may be provided for the secret keys. Alternatively or additionally, the secret keys may be derived by combining a private key of a sender and a public key of a recipient. The sender may be configured to send different sets of information to different receivers.

With regard to algorithm selection, the sender and the receiver may be configured to support different cryptography algorithms. The sender may check available space for in-band communication and perform sending of radio information only if space is available perform these operations. The sender and the receiver may be configured to support selected security mechanisms such as confidentiality (encryption), integrity, and authenticity (keyed hash). From time to time, adjustments may be performed with regard to packet flow. The sender may be configured to identify one or more flows of traffic to which the radio information is required to be transferred (e.g. identify packets that correspond to traffic initiation and those that follow). Based on that identification, the sender may be configured to transfer the radio information more or less frequently. For example, the sender may be configured to send the radio information in ‘x’ initial packets of a traffic flow and then in every nth packet after that.

It is noted that various non-limiting embodiments described herein may be used separately, combined or selectively combined for specific applications. Further, some of the various features of the above non-limiting embodiments may be used to advantage without the corresponding use of other described features. The foregoing description should therefore be considered as merely illustrative of the principles, teachings and exemplary embodiments of this invention, and not in limitation thereof.

It is to be understood that the above-described arrangements are only illustrative of the application of the principles of the present invention. Numerous modifications and alternative arrangements may be devised by those skilled in the art without departing from the scope of the invention, and the appended claims are intended to cover such modifications and arrangements.