Patent Application
20230353378
Among other things, the Internet Protocol (IP) describes discovery protocols. As one example, Neighbor Discovery Protocol (NDP) can be used by nodes to discover each other. For example, the specifications for IP version 6 (“IPv6”), which is a new version of IP, defines a protocol called Neighbor Discovery Protocol (“NDP”). IPv6 nodes (e.g., hosts and routers) use NDP to discover each other, exchange routing information, manage auto-configuration, and perform other tasks important to IP networking.
In some implementations, IP nodes implicitly trust NDP messages generated by other nodes. Without any inherent security mechanisms to provide confidentiality, integrity, or availability, such implementations are susceptible to abuse. In addition, although IPSec (Internet Protocol Security) may be used to secure NDP messages, IPSec requires significant manual configuration and is unwieldy to deploy in large environments.
Subsequent efforts, such as SEcure Neighbor Discovery (“SEND”) which uses public-key cryptography and digital certificates, to secure NDP messages still have numerous shortcomings. In practice, an effective deployment of SEND required a significant investment in Public Key Infrastructure (“PKI”), which can be cumbersome and costly to operate. As a result, SEND has been met with limited acceptance.
While attempts have been made to add security to NDP, there are numerous drawbacks that leave room for improvement.
As described herein, some aspects relate to systems and methods involving secure device authentication using aspects of a zero-knowledge password proof approach are disclosed. In one example, a device may generate a self-authenticating message including its identity and/or its capability attributes. The device may use a secret value, random nonce, public ephemeral value (PEV), session key, and/or other values to generate the self-authenticating message. The secret value may be unknown to a device receiving the self-authenticating message. With the use of pre-loaded values, including a verifier, the receiving device may compare its own host-generated keyed-hash message authentication code (“HMAC”) with the router-generated HMAC to verify the authenticity of the message. In one example, such authentication may be useful, inter alia, on an Internet Protocol (IP) network utilizing NDP.
In one example, aspects may relate to a method involving generating, by a computing device (e.g., wireless router apparatus), a self-authenticating message. The message may include information relating the identity and/or capability attributes of the computing device. At least portions of the message may be hashed using at least a secret value unknown to self-configurable host apparatuses, which receive the message. The self-configurable host apparatuses, upon receipt of the self-authenticating message, may calculate an authentication code (e.g., a hashed message authentication code) to authenticate the message. The host apparatus may use one or more values, such as a public static value, a verifier, a public ephemeral value, and/or other values to calculate the HMAC. The host may compare the generated HMAC to the received router’s HMAC to determine if the message is authentic.
The preceding presents a simplified summary in order to provide a basic understanding of some aspects of the disclosure. The summary is not an extensive overview of the disclosure. It is neither intended to identify key or critical elements of the disclosure nor to delineate the scope of the disclosure. The summary merely presents some concepts of the disclosure in a simplified form as a prelude to the description below.
The present disclosure is illustrated by way of example and not limited in the accompanying figures in which like reference numerals indicate similar elements and in which:
In the following description of various illustrative embodiments, reference is made to the accompanying drawings, which form a part hereof, and in which is shown, by way of illustration, various embodiments in which aspects of the disclosure may be practiced. It is to be understood that other embodiments may be utilized, and structural and functional modifications may be made, without departing from the scope of the present disclosure.
Communication protocols exist that use neighbor discovery protocols to discover networks and/or machines (e.g., hosts and routers). Some neighbor discovery protocols operate using particular message types (e.g., a Router Advertisement message type). A newer version of the Internet Protocol, IPv6, includes a version of NDP that also uses a particular Router Advertisement (“RA”) message type. However, the NDP defined for IPv6 provides little in the way of native security; this leaves IPv6′s RA messages susceptible to abuse and forgery. While solutions like IPSec and SEND have been proposed to improve IPv6′s NDP security, they can be cumbersome and/or difficult to implement and have failed to gain widespread acceptance.
Systems and methods disclosed herein can be used for authenticating one or more types of messages communicated between a router and hosts, such as RA messages (or other message types) sent from a router to hosts. Various derivations of the approaches disclosed herein are also contemplated. Specifically, many of the disclosed approaches use variations of zero-knowledge password proofs (“ZKPP”) and augmented password-authenticated key agreements (“PAKE”) to authenticate particular kinds of NDP messages, such as RA messages, and other kinds of broadcast/multicast messages. In some examples, aspects of the novel approach may be referred to as an end-to-end zero-knowledge password proof for router authentication (“ZKPPRA”) solution.
Some aspects disclosed herein relate to message-level authentication as compared to user-level authentication. In addition, some aspects describe the directionality of authentication to be from a centralized router or gateway to one or more hosts (e.g., client computing devices). As such, the authentication protocol may be unidirectional in nature, and may eliminate, in some examples, the need for hosts to provide random nonces as part of the authentication process. In some examples, static values may be used instead, and hosts may not need to transmit information to an authenticating router. The ZKPPRA solution may include one or more of the aforementioned features.
In one example of a ZKPPRA solution, an authentication mechanism and/or protocol may undergo some preparations, such as one or more of the following preparatory measures: (1) preparation stage (e.g., router preparation to produce authenticated protocol data units (“PDUs”) or messages); (2) PDU production stage (e.g., production of authenticated PDUs, for example, a signed IPv6 RA message); and/or (3) PDU validation stage (e.g., validation of authenticated PDUs). In addition, in some examples of a ZKPPRA solution one or more of the following preparatory measures may be taken: (1) standardization on specific key exchange algorithms and message digest algorithms, (2) definition of configuration parameters for routers, and/or (3) definition of configuration parameters for hosts. Although the preceding examples have described steps of the process in terms of stages, the disclosure is not so limited. Rather, one or more stages may be conflated into another stage, may be divided into multiple additional stages, may be performed concurrently with another stage, or may be optional, as appropriate.
The network 100 may be a telecommunications network, a multi-service operator (MSO) network, a cable television (CATV) network, a cellular network, a wireless network, an optical fiber network, a coaxial cable network, a hybrid fiber-coaxial (HFC) network, or any other suitable type of information distribution network or combination of networks. For example, the network 100 may be a cellular broadband network communicating with multiple communications access points, such as a wireless communications tower 130. In another example, the network 100 may be a coaxial system comprising a cable modem termination system (CMTS) communicating with numerous gateway interface devices (e.g., a gateway interface device 111 in an example home 102a). In another example, the network 100 may be a fiber-optic service system comprising optical fibers extending from an optical line terminal (OLT) to numerous optical network terminals (ONTs) communicatively coupled with various gateway interface devices. In another example, the network 100 may be a digital subscriber line (DSL) system that includes a local office 103 communicating with numerous gateway interface devices. In another example, the network 100 may be an HFC network in which Internet traffic is routed over both optical and coaxial communication paths to a gateway interface device in or near a user’s home. Various aspects of the disclosure may operate on one or more of the networks described herein or any other suitable network architectures now known or later developed.
The network 100 may use a series of interconnected communication links 101 (e.g., coaxial cables, optical fibers, wireless links, etc.) to connect premises such as homes 102 or other user environments to a local office 103. The communication links 101 may include any suitable wired communication links, wireless communication links, communications networks, or combinations thereof. For example, portions of the communication links 101 may be implemented with fiber-optic cable, while other portions of the communication links 101 may be implemented with coaxial cable. The communication links 101 may also include various communications components such as splitters, filters, amplifiers, wireless components, and other suitable components for communicating data. Data may include, for example, internet data, voice data, weather data, content data, and any other suitable information. Content data may include, for example, video content, audio content, media on demand, video on demand, streaming video, television programs, text listings, graphics, advertisements, and other content. A content item may represent an individual piece of content, such as a media content item (e.g., a particular movie, television episode, online video clip, song, audio recording, image, or other media content) or any other data. In some instances, a content item may be fragmented into segments, such as a plurality of two-second video fragments that may be separately addressed and retrieved.
The local office 103 may transmit downstream information signals onto communication links 101, and premises such as a home 102 may receive and process those signals. In certain implementations, communication links 101 may originate from a local office 103 as a single communications path, and may be split into any suitable number of communication links to distribute data to homes 102 and various other destinations. Although the term home is used by way of example, homes 102 may include any type of user environment, such as single family homes, apartment complexes, businesses, schools, hospitals, parks, and other suitable environments and combinations of environments.
The local office 103 may include an interface 104, which may be a computing device configured to manage communications between devices on the network of communication links 101 and backend devices, such as server 105, server 106, and server 107. For example, an interface 104 may be a cable modem termination system (CMTS). The termination system may be as specified in a standard, such as, in an example of an HFC-type network, the Data Over Cable Service Interface Specification (DOCSIS) standard, published by Cable Television Laboratories, Inc. The termination system may be configured to transmit data over one or more downstream channels or frequencies to be received by various devices, such as modems in homes 102, and to receive upstream communications from those modems on one or more upstream frequencies.
The local office 103 may include one or more network interfaces 108 for communicating with one or more external networks 109. One or more external networks 109 may include, for example, one or more telecommunications networks, Internet Protocol networks, cellular communications networks (e.g., Global System for Mobile Communications (GSM), Code Division Multiple Access (CDMA), and any other suitable 2nd, 3rd, 4th and higher generation cellular communications networks), cellular broadband networks, radio access networks, fiber-optic networks, local wireless networks (e.g., Wi-Fi, WiMAX), satellite networks, and any other suitable networks or combinations of networks.
The local office 103 may include a variety of servers that may be configured to perform various functions. Local office 103 may include one or more push servers 105 for generating push notifications to deliver data, instructions, or both to devices that are configured to detect such notifications. For example, push server 105 may transmit an instruction to a device to transfer service from one wireless network or communications access point to another wireless network or communications access point. Local office 103 may include one or more server computing devices (e.g., content servers 106) configured to provide content (e.g., media content) to devices. Local office 103 may include one or more application servers 107. For example, application server 107 may be used to implement a caching device, such as a cache server, for the content stored in or provided by content server 106.
Homes 102 may include a single family home, an apartment, a restaurant, an office suite, or any other suitable indoor environment and extend to an outdoor environment. Example home 102a may include an interface, which may include device 110, for communicating on communication links 101 with local office 103, one or more external networks 109, or both. For example, device 110 may be a coaxial cable modem (for coaxial cable links 101), a broadband modem (for DSL links 101), a fiber interface node (for fiber-optic links 101), or any other suitable device or combination of devices. In certain implementations, device 110 may be a part of, or communicatively coupled to, gateway interface device that provides access to a gateway 111. The gateway 111 may be, for example, a wireless router, a set-top box, a computer server, or any other suitable computing device or combination.
The gateway interface device 111 may be any suitable computing device for communicating with device 110 to allow one or more other devices in example home 102a to communicate with local office 103, one or more external networks 109, or other devices communicatively coupled thereto. The gateway 111 may include local network interfaces to provide communication signals to user devices in or near example home 102a, such as television 112, set-top box 113, personal computer 114, laptop computer 115, wireless device 116 (e.g., a wireless laptop, a tablet computer, a mobile phone, a portable gaming device), vehicular computing system 117 (e.g., a mobile computing system, navigation system, or entertainment system in an automobile, marine vessel, or aircraft) and any other suitable device
The
One or more aspects of the disclosure may be embodied in computer-usable data and/or computer-executable instructions, such as in one or more program modules, executed by one or more computers or other devices. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types when executed by a processor in a computer or other data processing device. The computer executable instructions may be stored on one or more computer readable media such as a hard disk, optical disk, removable storage media, solid state memory, RAM, etc. As will be appreciated by one of skill in the art, the functionality of the program modules may be combined or distributed as desired in various embodiments. In addition, the functionality may be embodied in whole or in part in firmware or hardware equivalents such as integrated circuits, field programmable gate arrays (FPGA), and the like. Particular data structures may be used to more effectively implement one or more aspects of the disclosure, and such data structures are contemplated within the scope of computer executable instructions and computer-usable data described herein. The various computing devices, servers and hardware described herein may be implemented using software running on another computing device.
Referring to
In some examples, when hashing at least part of the message to be a self-authenticating message 306, the router 300 may determine at least a portion of the message to be authenticated, and calculate a hash corresponding to the portion of the message to be authenticated. This router-generated hash may be calculated using a keyed-hashing for message authentication (HMAC) methodology (i.e., a router-HMAC). Other approaches to constructing a keyed message hash are contemplated for use in various examples herein. In addition to inserting the calculated router-HMAC into the message, a public ephemeral value (PEV) may also be inserted.
In the preceding example, the router 300 calculates a hash value using processing logic 302 (e.g., a microprocessor, an ASIC, or other hardware). In other examples, the router 300 may delegate the step of calculating a hash to a separate, trusted server computing device 106 in communication with the router 300. In any event, the calculations may use one or more configuration parameter values. Based on where the calculations will take place, the configuration parameter values may be stored in memory 304 at the router 300, or may be stored elsewhere. The router 300 may receive, in some examples via a secure communication channel, the configuration parameter values and use them to generate the PEV and other values. For example, the configuration parameters may correspond to an identification of a key exchange algorithm, an identification of a message digest algorithm, and an identification of an encryption/hashing algorithm for use in communicating on the network 210 between router 300 and hosts 308, 310.
The router 300 may use the one or more of the configuration parameter values and a secret value, which is known to the router 300, but not the host devices 308, 310, to generate various values, including, but not limited to, a random nonce, a PEV, a session key, and/or other values. The router 300 may use one or more of the random nonce, the PEV, and the session key to hash a portion of the message to generate a self-authenticating message 306.
Some examples of configuration parameters that may be defined, calculated, and/or recorded at the router 300 include, but are not limited to:
Some examples of configuration parameters that may be defined, calculated, and/or recorded at a host 308, 310 include, but are not limited to:
At least some of the aforementioned configuration data may be configured and/or produced on routers 300 participating in the generation of authenticated router messages. In some examples, the results of calculated values are configured on the hosts, and not the values used in such calculations. For example, hosts 308, 310 may be configured with the calculated value of the verifier, but lack knowledge of the privatekey value, which may be derived from other values, used to compute the verifier. Such an arrangement forms aspects of an end-to-end zero-knowledge password proof for router authentication (“ZKPPRA”) solution described herein.
A portion of an illustrative script that might run, in some examples, on a router 300 in accordance with various aspects disclosed herein is shown in Table 3 below. The aforementioned illustrative script may import one or more Python libraries, including, but not limited to, one or more of hashlib, random, hmac, string, sys, binascii, and/or other libraries. Although the example of Table 3 is illustrated in Python, the disclosure contemplates other programming languages may be used to cause effectively the same result.
The illustrative script may be written in Python and may generate verifiers, key material, and other parameters used to demonstrate one example of a ZKPPRA solution. In one example demonstrating various aspects of a ZKPPRA solution, an illustrative method may progress through one or more stages, including, but not limited to a preparation stage, a production stage, a validation stage, and/or other stages.
In an illustrative preparation stage, a router 300 may be configured and prepared to produce authenticated protocol data units (PDUs), as shown in
During setup, the router 300 and host 308 may be in possession of particular information. For example, the router 300 may be in possession of at least the password and privatekey values. The host 308 may be in possession of at least the verifier value. In some examples, the router 300 and host 308 may both be in possession of values including, but not limited to, values for:
Referring to
Moreover, in step 404, configuration parameters may be generated and installed for participating routers. Likewise, in step 406, configuration parameters may be generated and installed for participating hosts. In one example, PEV and subsequent key generations may be performed by the router 300. The router 300 may generate a nonce (e.g., a random value of the same size as the hash value produced by the selected hash algorithm, such as the 256-bit value:
0x457cb52343ca23fe5a4f52b6c51c8461f8cc7bd49e9ed0181ccd0c22f5941659).▫Then▫the router▫300▫may▫calculate▫a▫PEV▫(e.g.,▫generator^nonce▫mod▫prime,▫to▫output▫PEV▫= 0x83aecf5fdd8e8251a6bfb2ddb834e5952360b62b759e53c7c34ad03ccafd3cd57359b030e9 cc5da237550d0cdc547be2d605a37c10f94102481a5630d7342b660f2ce5c392a80fca9e431e 1b0b5bba39d7272e2a47c724d9eebaa64a35651a8760a828c67aea6988c9880c1af3efef4481 6ed184bacbe73e87c2c633a4c11682).▫The▫router▫300▫may▫also▫calculate▫a▫scramble▫value (e.g.,▫hash(PEV,▫PSV)▫to▫output▫scramble▫=
0x658c2fce8743f876b01c743ef02ae41f5f2fecc8bd5f01dd74120f2406e8006f).▫The▫router 300▫may▫use▫the▫generated▫scramble▫and▫other▫values▫to▫calculate▫S_r▫(i.e.,▫((PSV▫-▫multiplier *▫(generator^privatekey▫mod▫prime))^(nonce▫+▫scramble▫*▫privatekey)▫mod▫prime)▫to▫output S_r▫=
0x493d48b2a34c7bbba915155bbc2f53430c06b295f1886ac30d8c1cc7de61f335d60173342 259310802356cf31e533588bb688b227ab45fe06f8e64458d5ebd7d59233f8c1994e611ea9df 5d41cd11628eb3045db20071fb9d2dc5b9be5f31c16738f79d0351b7cdac6ed0a1881354d82 0d3c9149f00dd6bb393abc644142c5c4).▫Finally,▫the▫router▫300▫may▫calculate▫a▫session routerkey▫(e.g.,▫hash(S_r))▫to▫output▫a▫routerkey▫=
0xba26b5914f29f924315a30d8d3767e2663d6020788e59b554b799a74369a0f3b).
The ZKPPRA solution may make use of randomly generated nonces to, inter alia, deter replay attacks and/or to ensure the presence of fresh key material. Such an approach preserves that security posture to a partial extent by requiring routers 300 to similarly produce randomly generated values, which may subsequently be used to produce authenticated router messages. In some examples, the ZKPPRA solution may use per-session random nonces. This approach views the generation and/or reuse of the random values (referred to as public ephemeral values, or “PEVs”) as configurable. This may provide support for high levels of router 300 performance, such as immediate responses to router solicitation request messages. As such, PEVs may persist and be reused: never (e.g. one-time use, effectively a nonce); for a specific period of time (e.g. one hour); and/or for a specific number of authenticated message transmissions (e.g. for 1,024 Router Advertisement messages or other types of messages).
After the preparation stage, the router 300 may transmit authenticated messages (e.g., authenticated Router Advertisements or other types of messages) using a generated routerkey as a secret cryptographic key to use with a keyed-hash message authentication code (“HMAC”), an example of which is defined by RFC 2104, which is herein incorporated by reference in its entirety.
As illustrated in
The router 300 may calculate the specific Router Advertisement message options to be authenticated- i.e., Router Advertisement options (RAopts). The RAopts may comprise one or more Internet Control Message Protocol (ICMPv6) options, such as a source link-layer address (e.g., 00:50:56:9f:0d:00), a maximum transmission unit value (e.g., 1280), and/or a prefix (e.g., 2001:db8:1234:5678::/64). These may be represented as consecutive strings of hexadecimal characters or other types of characters. As a result, in one example, RAopts may equal:
0x1010050569f0d000501000000000500030440c0ffffffffffffffff0000000020010db8123456 780000000000000000L.
Subsequently, the router 300 may generate a keyed-hash message authentication code (HMAC) over all RAopts (e.g., RAhmac = hmac(routerkey, RAopts); such that RAhmac = 0xfd2556f76abb5ef53e020fa134aafc68d401a29ae74acf2473e2511c45fa99e).
In step 510, the router 300 may append (or insert somewhere other than the end of the message) an additional message authentication option that may contain at least:
For example, a RAhmac value and optional padding value may be included in the additional message authentication option. For example, the optional padding may be used to align the option on a predetermined (e.g., 64-bit or other number of predefined bits) boundary, or as desired in accordance with prevailing standards. Likewise, the new option length field may be calculated based on the cumulative length of all fields in the option, and not necessarily a predefined value. In other words, it may be variable based on the message digest algorithm selected and PEV.
Although the preceding example involves the creation of a new router authentication option type for purposes of constructing an authenticated PDU, such an example should not constrain a ZKPPRA solution in accordance with the disclosure. Rather, other approaches may also be taken to demonstrate that the construction of a signed router authentication is feasible within the ZKPPRA solution.
In step 512, the router 300 may transmit the authenticated message (e.g., router announcement) as normal. For example, an illustrative message authentication option may appear in a network packet capture as follows:
Meanwhile, an illustrative ZKPPRA packet (including Ethernet and/or IP headers) might appear in a network packet capture as follows:
Referring to
A session key may be generated in step 606. The system may determine which portion of the PDU to authenticate in step 608, and then in step 610, the system may proceed to calculate a host HMAC value over that portion of the PDU to be authenticated. For example, the host 308 may calculate a scramble value (e.g., scramble = 0x7f5deb9ddbe03077e0d2013128b37a02cd2b94debc0feab969ded85db99a978c) by providing a PEV and PSV as inputs into a hash function. In addition, the host 308 may calculate a session key using numerous values available at the host 308. For example, the host 308 may use the generated scramble and other values to calculate S_s = (PEV * (verifier^scramble mod prime))^staticvalue mod prime. Finally, the host 308 may calculate a session hostkey (e.g., hash(S_s)) to output a hostkey = 0xba26b5914f29f924315a30d8d3767e2663d6020788e59b554b799a74369a0f3b). A sample session key value may be:
In addition, the host 308 may calculate specific message options (e.g., RA message options) within the received PDU (e.g., message 306) to be authenticated (i.e., HRAopts value =
In step 612, the system determines whether the host HMAC value calculated in step 610 is the same as the router HMAC. If they are the same, then in step 614, the host 308 may accept the PDU (e.g., message 306) as authentic. Instead, if the host HMAC is not equal to the router HMAC, then in step 616, the host may flag the PDU as unauthenticated and reject the PDU. Rejecting the PDU (e.g., message 306) may include, but is not limited to, purging the PDU from memory, re-trying the comparison of the host HMAC to the router HMAC, quarantining the PDU in a memory storage area, inserting an entry in a log file, and/or other activity.
In accordance with various aspects disclosed herein, although various examples refer to “message,” the message need not be limited to its traditional meaning. Rather, “message” may be in the form of a protocol data unit (PDU) or may be in the form of a plurality of fragmented data packets that, when later assembled, serve a similar function as a single message. Alternatively, “message” in some environments may be in the form of a stream of data, which when collected and collectively interpreted, may serve a similar function as a message. Finally, although several examples refer to Router Advertisement messages, the disclosure is not so limited; other message types may be used in the spirit of the features disclosed herein.
In addition, although various examples reference to IPv6 networks, the disclosure is not so limited. Any network on which a neighbor discovery protocol (or functionally similar unicast, multicast, or broadcast protocol) is being used to establish communication between two or more communicatively coupled devices (e.g., routers with network stacks that can communicate with appropriately enabled nodes) is contemplated, and “network” covers all such networks.
Furthermore, while protocols such as ICMP and NDP have been referenced in the disclosure, other similar protocols may be substituted for one or more of the referenced protocols. In addition, in some instances the existing, referenced protocols may be extended to support one or more of the features disclosed herein, such as authentication. Updates to protocols may result in one or more modifications to the router and/or host devices and their operating systems. Some examples of such modification to existing referenced protocols include creating a new type of ICMPv6 informational message (e.g., with a “Type 150” value type, which is currently unassigned) similar to the “Type 134” value type currently in use with Router Advertisement messages. Alternatively, a new code could be assigned to an existing message type or a new message type. For example, currently “Code 0” is used for Router Advertisement messages, but a new code value could be assigned for messages enhanced with one or more features disclosed herein. In yet another alternative, a new option may be added to the list of existing options for a given message type. For example, several options for Router Advertisement messages include a Source Link-Layer Address (Option Type 1) and Prefix Information (Option Type 3). A new option type value may be assigned for messages 306 sent in accordance with various features disclosed herein. For example, Option Type 123, which is currently unassigned, of Router Advertisement messages may be reserved for messages 306 sent by a router 300 in accordance with various aspects disclosed herein.
In addition, in some examples, the router 300 and hosts 308, 310 described herein may each be preloaded with configuration data to facilitate a ZKPPRA solution, as described herein. Examples include, but are not limited to, IT management frameworks, such as a group policy (e.g., Active Directory Group Policy for Microsoft Windows operating systems), mobile device management (“MDM”) frameworks for managing configuration profiles for iOS devices like the iPhone, iPad, etc., connection manager frameworks, such as Wi-Fi Alliance’s Passpoint™ initiative, and others. Furthermore, although an asymmetric key exchange protocol, such as Diffie-Hellman Key Agreement (as defined by RFC 2631, which is herein incorporated by reference in its entirety and a copy of which is being filed in an Information Disclosure Statement concurrent with this application filing), has been be described to support authentication of Router Advertisement messages, the disclosure is not so limited. Other protocols may be substituted or integrated into the protocol described herein while remaining within the spirit of the disclosure. Likewise, a cryptographically strong digest algorithm, such as the 256-bit variant of Secure Hash Algorithm (SHA-256) (as defined by RFC 6234, which is herein incorporated by reference in its entirety and a copy of which is being filed in an Information Disclosure Statement concurrent with this application filing), has been described to support authentication of Router Advertisement messages, the disclosure is not so limited.
Aspects of the disclosure have been described in terms of illustrative embodiments thereof. While illustrative systems and methods as described herein embodying various aspects of the present disclosure are shown, it will be understood by those skilled in the art, that the disclosure is not limited to these embodiments. Modifications may be made by those skilled in the art, particularly in light of the foregoing teachings. For example, each of the features of the aforementioned illustrative examples may be utilized alone or in combination or subcombination with elements of the other examples. For example, any of the above described systems and methods or parts thereof may be combined with the other methods and systems or parts thereof described above. For example, one of ordinary skill in the art will appreciate that the steps illustrated in the illustrative figures may be performed in other than the recited order, and that one or more steps illustrated may be optional in accordance with aspects of the disclosure. It will also be appreciated and understood that modifications may be made without departing from the true spirit and scope of the present disclosure. The description is thus to be regarded as illustrative instead of restrictive on the present disclosure.
It is noted that various connections are set forth between elements in the following description. These connections are described in general and, unless specified otherwise, may be direct or indirect; this specification is not intended to be limiting in this respect.
This application is a continuation of and claims priority to U.S. Pat. Application No. 17/144,863, filed Jan. 8, 2021, which is a continuation of U.S. Pat. Application No. 14/316,406, filed on Jun. 26, 2014 (now U.S. Pat. No. 10,931,456), each of which is hereby incorporated by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 17144863 | Jan 2021 | US |
| Child | 18329955 | US | |
| Parent | 14316406 | Jun 2014 | US |
| Child | 17144863 | US |
