Patent Publication Number: US-11650921-B2

Title: Method and system for establishing a distributed network without a centralized directory

Description:
FIELD 
     The present disclosure relates to establishing a connection between two nodes in a communication network without use of a centralized directory or mapping identifiers, specifically the use of lookup messages and specialized values to enable a node in a distributed communication network to find another without the use of a centralized directory. 
     BACKGROUND 
     Communication networks can utilize a variety of different topologies and architectures. Some topologies including having centralized nodes that communicate with a vast number of other nodes, enabling easy communications across the network through these centralized nodes. Other topologies, such as mesh networks, are set up through a web of connections, where each node may be connected to only a handful of other nodes, but where there is always an unbroken path from any one node to any other. Often times, these types of networks utilize centralized directories, where address or other communication data can be stored for every node in the network. Thus, when a first node needs to contact a second node, they can identify how in the directory and then carry out the communication. See, US Pub. Pat. Appl. No. 2017/0148016A1 or Quorum (https://docs.goquorum.consensys.net/en/stable/Concepts/Privacy/PrivateTransaction Lifecycle/), where transactions between parties may be conducted off-chain with a hash reference to the final agreement and/or commitment distributed on-chain in a blockchain node environment. To be able to do this, nodes on the network acting on behalf of chain participants need to connect directly to exchange transaction data for which, in turn, support for routing of transient point-to-point connections is required. 
     However, distributed communication networks do not utilize centralized directories. For example, blockchain networks operate using a plurality of nodes that communicate with other nodes, but without any central directory. In many instances, a centralized directory may be impossible or impractical depending on the architecture of the network and the number of nodes. Additionally, if one particular node wants to communicate with another particular node, there may no explicit ability to do so in the communication network itself. Instead, the node can simply broadcast a message, or may use an alternative communication method to retrieve an address or other data for the other node. Such methods can be very inefficient and, in some cases, unavailable. Thus, there is a need for technology in a distributed communication network that can enable a first node to locate a second node in the network without the use of a centralized directory. 
     SUMMARY 
     The present disclosure provides a description of systems and methods for establishing a connection between two nodes in a communication network without requiring the use of a centralized directory. When an originating node needs to connect with a target node, they can send a lookup message to any connected nodes, referred to herein as intermediary nodes, where the lookup message includes a term that may only be satisfied by the proper target node. When a node receives the message, they can check to see if they satisfy the lookup term, which would make them the target, and then connect back to the originating node using an address in the lookup message. If they are not the target, the intermediary node can check a cached directory to see if they know the target node. If so, they can forward the lookup message directly to the target node, which can then connect back to the originating node. If the intermediary node does not know the target node, they can forward on the message to their own peers, which can continue the process. The result is that the message is distributed out through the network to reach the target in the most efficient manner possible, with each intermediary having no knowledge of the purpose of the connection or, in many cases, the identity of the target itself, as only the target may be able to satisfy the lookup term. Thus, security and privacy can be maintained in a distributed network while also enabling any two nodes to connect in an efficient manner. 
     A method for establishing a connection between two nodes in a communication network without use of a centralized directory or mapping identifiers includes: storing, in a memory of an intermediary node in a communication network, a directory cache comprised of a plurality of directory entries, where each directory entry includes a response term, a communication address, a timestamp, and an entry time-to-live value; receiving, by a receiver of the intermediary node, a lookup message from an originating node, where the lookup message includes at least a lookup term, a network address of the originating node, and a lookup time-to-live value; determining, by a processor of the intermediary node, if a specific entry in the directory cache stored in the intermediary node includes a response term that satisfies the lookup term; and if the processor determines that a specific entry includes a response term that satisfies the lookup term, establishing, by the intermediary node, a communication channel with a target node in the communication network using the communication address included in the specific entry, and forwarding, by a transmitter of the intermediary node, the lookup message to the target node using the established communication channel, or if the processor determines that no specific entry in the directory cache includes a response term that satisfies the lookup term, forwarding, by the transmitter of the intermediary node, the lookup message to a plurality of connected nodes with active communication connections to the intermediary node in the communication network. 
     A system for establishing a connection between two nodes in a communication network without use of a centralized directory or mapping identifiers includes: a communication network; an originating node in the communication network; a plurality of additional nodes in the communication network; a target node in the communication network; and an intermediary node in the communication network, the intermediary node including a memory storing a directory cache comprised of a plurality of directory entries, where each directory entry includes a response term, a communication address, a timestamp, and an entry time-to-live value, a receiver receiving a lookup message from an originating node, where the lookup message includes at least a lookup term, a network address of the originating node, and a lookup time-to-live value, a transmitter, and a processor determining if a specific entry in the directory cache stored in the intermediary node includes a response term that satisfies the lookup term, wherein if the processor determines that a specific entry includes a response term that satisfies the lookup term, the processor establishes a communication channel with a target node in the communication network using the communication address included in the specific entry, and the transmitter forwards the lookup message to the target node using the established communication channel, or if the processor determines that no specific entry in the directory cache includes a response term that satisfies the lookup term, the transmitter forwards the lookup message to a plurality of connected nodes with active communication connections to the intermediary node in the communication network. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING FIGURES 
       The scope of the present disclosure is best understood from the following detailed description of exemplary embodiments when read in conjunction with the accompanying drawings. Included in the drawings are the following figures: 
         FIG.  1    is a block diagram illustrating a high-level system architecture for establishing a connection between nodes in a distributed communication network in accordance with exemplary embodiments. 
         FIG.  2    is a block diagram illustrating a communication node of the system of  FIG.  1    for in accordance with exemplary embodiments. 
         FIG.  3    is a flow diagram illustrating a process for facilitating communications in a distributed communication network without a centralized directory in accordance with exemplary embodiments. 
         FIG.  4    is a flow chart illustrating an exemplary method for establishing a connection between two nodes in a communication network without use of a centralized directory or mapping identifiers in accordance with exemplary embodiments. 
         FIG.  5    is a block diagram illustrating a computer system architecture in accordance with exemplary embodiments. 
     
    
    
     Further areas of applicability of the present disclosure will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description of exemplary embodiments are intended for illustration purposes only and are, therefore, not intended to necessarily limit the scope of the disclosure. 
     DETAILED DESCRIPTION 
     System for Establishing Connections in a Communication Network 
       FIG.  1    illustrates a communication network  100  that includes a plurality of computing nodes. In an exemplary embodiment, the communication network  100  may be a distributed network that lacks a centralized directory, where each computing node may be in communication with one or more other computing nodes in the communication network  100 , but where there is no centralized node to facilitate communications and no central directory of member nodes and their network addresses. Each of the computing nodes may be a specially configured computing device, such as illustrated in  FIG.  2    and described in detail below, that is configured to perform the functions discussed herein for facilitating the connection of two nodes in the communication network  100 . 
     In the communication network  100 , an originating node  102  may want to establish a connection with a target node  104 . In an example, the communication network  100  may be a blockchain network used for electronic payments, where the originating node  102  may be a first business that wants to transact with a target node  104  as a second business. The originating node  102  may have identifying information for the target node  104  but may be unaware of the network address for the target node  104  in the communication network  100 . For example, the originating node  102  may be a first bank that knows it needs to make a payment to a second bank, and knows of the second bank, but not know how to contact the second bank to arrange for the payment or get additional information. 
     In order to connect to the target node  104 , the originating node  102  may transmit a lookup message to every node connected thereto. The lookup message may include a lookup term, a network address for the originating node  102 , and a time-to-live (TTL) value. The TTL value may be an expiration time for the message, such as to prevent the identification of long communication paths and stop the process if the target node  104  is not successfully identified. In some instances, the TTL value may be represented as a timestamp (e.g., five minutes after the time at which the response message is generated). In other instances, the TTL value may be a time value itself (e.g., 300 seconds). In some embodiments, the lookup message may also include a value that indicates to any node in receipt of the lookup message that the message pertains to a lookup function, as discussed herein. 
     The lookup term may be an identification value or other item of data that may be recognizable as associated with the target node  104 , such as a name or identification number thereof, or may be recognizable by the target node  104  as the target thereof. For instance, the lookup term may be a hashed value, where the target node  104  may be aware of the underlying value and may hash the underlying value, which may result in the lookup term and thus indicate to the target node  104  that they are in the target. In the above example, the lookup term may be a hashed or encrypted transaction account number, where the target node  104  would be able to identify the transaction account number and, in some instances, validate that the transaction account is issued by that bank. In some cases, the lookup message may include additional data to be used to determine if a node is the target node  104  for the lookup message. For example, the lookup message may include a data value, such as a random word, that must be hashed by the target node  104  and, if the result is the same as the lookup term, the target node  104  will know they are the target. 
     If the originating node  102  is directly connected to the target node  104  (e.g., and may be unaware that a node in connection therewith is their target), the lookup message may be sent directly to the target node  104 . The target node  104  may receive the lookup message and may, from the lookup term, identify itself as the target, as discussed in more detail below. The lookup message may also be transmitted to any other nodes connected to the originating node  102 , such as the intermediary nodes  106  illustrated in  FIG.  1   . Each intermediary node  106  may receive the lookup message and may determine that it is not the target of the lookup message (e.g., due to the lookup term referring to a different node, or other inability to satisfy the lookup term). 
     The intermediary node  106  may then query a directory cache stored in the intermediary node  106  to determine if it knows the target node  104 . The directory cache may be a cache of directory entries stored in each node in the communication network  100  that includes address information for other nodes, response terms for the nodes, and timestamps for each node. The address information may be the latest communication address received for that node in the communication network  100 . The timestamp may be a time at which the communication address was received by the node. The response term may be an identification value or other data that may satisfy a lookup term if the associated node is the target for a lookup message. For example, if each node in the communication system  100  has a proper name, the response terms in the directory cache may be the proper name. The directory cache may be updated any time any of the information is received by a node. For instance, when an intermediary node  106  receives the lookup message, it may update the directory cache to include an entry for the originating node  102  that includes the network address and lookup term from the lookup message, as well as a timestamp for the present time or the TTL in the lookup message. 
     The intermediary node  106  may use the directory cache to determine if the intermediary node  106  knows any other node that may be the target node  104  where the response term satisfies the lookup term. For example, the lookup term may be an encrypted value, where the response terms are public keys unique to the associated nodes. In such an example, successful decryption of the value using a public key may satisfy the lookup term and indicate the associated node as the target node  104 . In some cases where the response term may be an encrypted value, the value may only be decrypted by the target node  104  (e.g., the value may be encrypted using a public key of a cryptographic key pair for which only the target node  104  has the private key). In such cases, the intermediary node  106  may never be able to identify the target node  104  unless the intermediary node  106  is also the target node  104 . 
     If the intermediary node  106  is able to identify that it knows the identity of the target node  104 , the intermediary node  106  may establish a communication channel with the target node  104  using the communication information included in the directory cache. The intermediary node  106  may then forward the lookup message to the target node  102  using the established communication channel. If the intermediary node  106  does not identify the target node  1046 , the intermediary node  106  may forward the lookup message to any additional nodes  108  that it has an active communication channel within the communication network  100 . Those additional nodes  108  may then process the lookup message similarly: determine if the node itself is the target node  104 , determining if it knows the target node  104  and forwarding the lookup message thereto, or forwarding the lookup message to any further additional nodes  108  in connection therewith. 
     In some embodiments, the TTL value in the lookup message may be decremented or otherwise processed by an intermediary node  106  or additional node  108  prior to forwarding. For instance, if the TTL value is an expiration time, the lookup message may only continue to be forwarded on until the expiration time has passed. If the TTL value is a time value, the time may be decremented by the amount of time it takes for the intermediary node  106  or additional node  108  to forward the lookup message from the time of receipt. For example, if it takes the intermediary node  106  twenty seconds to attempt to satisfy the lookup term (e.g., check if the node itself is the target) and to attempt to identify the target node  104  in its directory cache, the intermediary node  106  may decrement the TTL value by twenty seconds before forwarding to additional nodes  108 . 
     Once the target node  104  has received the lookup message, such as by identifying a response term that satisfies the lookup term, the target node  104  may establish a communication channel with the originating node  102  using the network address from the lookup message. In some cases, the response term may be provided during the establishing of the communication channel, such as to prove to the originating node  102  that the target node  104  is the target. In other cases, the communication channel may be opened with the originating node  102  first, and the response term exchanged using the communication channel. The response term may be validated by the originating node  102 , such as to ensure that the target node  104  is the intended target (e.g., and not an imposter). For instance, in the bank example, the response term may be proof that the second bank issued the transaction account that matches the transaction account number in the lookup message. In another example, the response term may be the decrypted lookup term that was decrypted using the target node&#39;s private key. If the response term is validated, then the originating node  102  and target node  104  can exchange any communications as desired. 
     In some embodiments, a response message may be transmitted by the target node  104  back through the other nodes in the communication network  100 . For example, the target node  104  may generate a response message that includes the response term, a new TTL value, and the address at which the target node  104  may be contacted by the originating node  102 . In some cases, the response message may also include the value identifying the lookup operation or a response operation, the network address for the originating node  102 , and/or the lookup term. The response message may then be forwarded on through the additional nodes  108  and/or intermediary nodes  106  back to the originating node  102 . In such cases, the originating node  102  may initiate the communication channel with the target node  104  using the address provided in the response message. In these embodiments, each node that receives a response message may update their directory cache to insert or update entries for the target node  104  to include the new TTL value in the response message, the network address, and the response term, and the timestamp, as applicable. 
     In some embodiments, a node may further include a lookup cache, which may be in addition to, separate from, or included in as part of the directory cache. In such embodiments, the lookup cache may be used by the node to store entries for lookup messages transmitted to other nodes (e.g., the originating node  102  may store an entry in its lookup cache for the lookup messages transmitted thereby). The lookup cache may be used by a node to detect when a received lookup message is its own lookup message, such as by a comparison of the lookup term included therein and/or other data. In such cases, the node may discard the received lookup message after it determines it was sent by itself (e.g., based on finding a matching entry in the lookup cache) and may thus not expend resources and processing of the received lookup message. In these instances, potentially disruptive loops of messages can be avoided by checking a lookup cache prior to processing of a received lookup message as discussed above. In some cases, the directory cache may be used as the lookup cache, where an entry may have an additional flag or other data value used to indicate that the node was the originator of that lookup message. 
     The methods and systems discussed herein enable an originating node  102  to locate and establish a communication channel with a target node  104  in a communication network  100  without the use of a centralized directory. In addition to not using a centralized directory, the communication network  100  does not need any mapping identifiers. In cases where lookup terms and response terms utilize encryption, hashing, or other cryptographic techniques, no node may be able to directly identify any other node, maintaining fully security and anonymity in the network. In these cases, a lookup message can be transmitted through the communication network  100  and may only be used by the proper target node  104 , enabling a fast, efficient, and still secure connecting of the originating node  102  with a target node  104 . Thus, the methods and systems discussed herein maintain all of the advantages of a decentralized, distributed network with the communication capabilities of a traditional, centralized network. 
     Computing Node 
       FIG.  2    illustrates an embodiment of the computing node  200 , which may be the originating node  102 , target node  104 , intermediary node  106 , and/or additional node  108  in the communication network  100  of  FIG.  1   . It will be apparent to persons having skill in the relevant art that the embodiment of the computing node  200  illustrated in  FIG.  2    is provided as illustration only and may not be exhaustive to all possible configurations of the computing node  200  suitable for performing the functions as discussed herein. For example, the computer system  500  illustrated in  FIG.  5    and discussed in more detail below may be a suitable configuration of the computing node  200 , which may perform any functions of any of the nodes discussed herein. 
     The computing node  200  may include a receiving device  202 . The receiving device  202  may be configured to receive data over one or more networks via one or more network protocols. In some instances, the receiving device  202  may be configured to receive data from other computing nodes  200 , and other systems and entities via one or more communication methods, such as radio frequency, local area networks, wireless area networks, cellular communication networks, Bluetooth, the Internet, etc. In some embodiments, the receiving device  202  may be comprised of multiple devices, such as different receiving devices for receiving data over different networks, such as a first receiving device for receiving data over a local area network and a second receiving device for receiving data via the Internet. The receiving device  202  may receive electronically transmitted data signals, where data may be superimposed or otherwise encoded on the data signal and decoded, parsed, read, or otherwise obtained via receipt of the data signal by the receiving device  202 . In some instances, the receiving device  202  may include a parsing module for parsing the received data signal to obtain the data superimposed thereon. For example, the receiving device  202  may include a parser program configured to receive and transform the received data signal into usable input for the functions performed by the processing device to carry out the methods and systems described herein. 
     The receiving device  202  may be configured to receive data signals electronically transmitted by other computing nodes  200  that may be superimposed or otherwise encoded with lookup messages, response messages, and other data used in the establishing and operation of communication channels in the communication network  100 . Lookup messages and response messages may include network addresses, lookup or response terms, identification values indicating operations to be performed, TTL values, and other data as discussed herein. 
     The computing node  200  may also include a communication module  204 . The communication module  204  may be configured to transmit data between modules, engines, databases, memories, and other components of the computing node  200  for use in performing the functions discussed herein. The communication module  204  may be comprised of one or more communication types and utilize various communication methods for communications within a computing device. For example, the communication module  204  may be comprised of a bus, contact pin connectors, wires, etc. In some embodiments, the communication module  204  may also be configured to communicate between internal components of the computing node  200  and external components of the computing node  200 , such as externally connected databases, display devices, input devices, etc. The computing node  200  may also include a processing device. The processing device may be configured to perform the functions of the computing node  200  discussed herein as will be apparent to persons having skill in the relevant art. In some embodiments, the processing device may include and/or be comprised of a plurality of engines and/or modules specially configured to perform one or more functions of the processing device, such as a querying module  214 , generation module  216 , validation module  218 , etc. As used herein, the term “module” may be software executed on hardware or hardware particularly programmed to receive an input, perform one or more processes using the input, and provides an output. The input, output, and processes performed by various modules will be apparent to one skilled in the art based upon the present disclosure. 
     The computing system  200  may include a directory cache  206 . The directory cache  206  may be configured to store a plurality of directory entries  208  using a suitable data storage format and schema. The directory cache  206  may be a relational database that utilizes structured query language for the storage, identification, modifying, updating, accessing, etc. of structured data sets stored therein. Each directory entries  208  may be a structured data set configured to store data related to another computing node  200  in the communication network  100 . A directory entry  208  may include one or more terms associated with the related computing node  200 , such as lookup terms and/or response terms, the latest network address received for the related computing node  200 , a time at which the latest network address was received, and a TTL value. Such data may be parsed from lookup messages and/or response messages received by the computing node  200 . 
     The computing node  200  may also include a memory  212 . The memory  212  may be configured to store data for use by the computing node  200  in performing the functions discussed herein, such as public and private keys, symmetric keys, etc. The memory  212  may be configured to store data using suitable data formatting methods and schema and may be any suitable type of memory, such as read-only memory, random access memory, etc. The memory  212  may include, for example, encryption keys and algorithms, communication protocols and standards, data formatting standards and protocols, program code for modules and application programs of the processing device, and other data that may be suitable for use by the computing node  200  in the performance of the functions disclosed herein as will be apparent to persons having skill in the relevant art. In some embodiments, the memory  212  may be comprised of or may otherwise include a relational database that utilizes structured query language for the storage, identification, modifying, updating, accessing, etc. of structured data sets stored therein. The memory  212  may be configured to store, for example, cryptographic keys, salts, nonces, the directory cache  206 , hashing algorithms, encryption algorithms, communication channel data, etc. 
     The computing node  200  may include a querying module  214 . The querying module  214  may be configured to execute queries on databases to identify information. The querying module  214  may receive one or more data values or query strings and may execute a query string based thereon on an indicated database, such as the directory cache  206  of the computing node  200  to identify information stored therein. The querying module  214  may then output the identified information to an appropriate engine or module of the computing node  200  as necessary. The querying module  214  may, for example, execute a query on the directory cache  206  to identify a directory entry  208  that includes a response term that satisfies a lookup term, for forwarding of a received lookup message to a network address included therein. 
     The computing node  200  may also include a generation module  216 . The generation module  216  may be configured to generate data for use by the computing node  200  in performing the functions discussed herein. The generation module  216  may receive instructions as input, may generate data based on the instructions, and may output the generated data to one or more modules of the computing node  200 . For example, the generation module  216  may be configured to generate response terms, new response messages, lookup terms, new lookup messages, communication channels, etc. 
     The computing node  200  may also include a validation module  218 . The validation module  218  may be configured to perform validations for the computing node  200  as part of the functions discussed herein. The validation module  218  may receive instructions as input, which may also include data to be used in performing a validation, may perform a validation as requested, and may output a result of the validation to another module or engine of the computing node  200 . The validation module  218  may, for example, be configured to validate a response term as satisfying a lookup term, where such a validation may be dependent on the lookup term and functions of the communication network  100 . For instance, validation may consist of matching the terms as exact values, attempting a decryption or hash using one of the values, etc., as discussed herein. 
     The computing node  200  may also include a transmitting device  220 . The transmitting device  220  may be configured to transmit data over one or more networks via one or more network protocols. In some instances, the transmitting device  220  may be configured to transmit data to other computing nodes  200  and other entities via one or more communication methods, local area networks, wireless area networks, cellular communication, Bluetooth, radio frequency, the Internet, etc. In some embodiments, the transmitting device  220  may be comprised of multiple devices, such as different transmitting devices for transmitting data over different networks, such as a first transmitting device for transmitting data over a local area network and a second transmitting device for transmitting data via the Internet. The transmitting device  220  may electronically transmit data signals that have data superimposed that may be parsed by a receiving computing device. In some instances, the transmitting device  220  may include one or more modules for superimposing, encoding, or otherwise formatting data into data signals suitable for transmission. 
     The transmitting device  220  may be configured to electronically transmit data signals to other computing nodes  200  that may be superimposed or otherwise encoded with lookup messages, response messages, and other data used in the establishing and operation of communication channels in the communication network  100 . Lookup messages and response messages may include network addresses, lookup or response terms, identification values indicating operations to be performed, TTL values, and other data as discussed herein. 
     Process for Facilitating Communication Channels 
       FIG.  3    illustrates a process  300  for facilitating the establishing of a communication channel between an originating node  102  and a target node  104  in the communication network  100  of  FIG.  1    by a computing node  200 , such as illustrated in  FIG.  2   , where the computing node  200  may be the target node  104 , an intermediary node  106 , or an additional node  108 . 
     In step  302 , the receiving device  202  of the computing node  200  may receive a lookup message from another computing node  200  in the communication network  100 . The lookup message may include at least a lookup term, network address for the originating node  102  of the lookup message, and a TTL value. In step  304 , the generation module  216  of the computing node  200  may generate a response value, such as using the lookup term or other data included in the lookup message and other data that may be available to the computing node  200 , such as stored in the memory  212  thereof, such as a cryptographic key. In step  306 , the validation module  218  of the computing node  200  may determine if the response term matches or otherwise satisfies the lookup term. 
     If the response term satisfies the lookup term, then the computing node  200  is the target node  104  for the lookup message. In such cases, the process  300  may proceed to step  308 , where the generation module  216  may generate a response message that includes the response term, a network address for the computing node  200 , and a new TTL value. The transmitting device  220  of the computing node  200  may electronically transmit the response message directly to the originating node  102  using the address found in the lookup message, or through one or more other computing nodes  200  in the communication network  100 . 
     If the response term does not satisfy the lookup term, then the computing node  200  is not the target node  104 . In such cases, the process  300  proceeds to step  310 , where the querying module  214  of the computing node  200  executes a query on the directory cache  206  of the computing node  200  to determine if there is a directory entry  208  that satisfies the lookup term. If such a directory entry  208  is found, then, in step  312 , the validation module  218  may determine if the TTL value included in the directory entry  208  has expired (e.g., by checking a present time against the timestamp and TTL value in the directory entry  208 ). If the TTL value has not expired, then, in step  314 , the transmitting device  220  of the computing node  200  may forward the lookup message to the target node  104  using communication data found in the identified directory entry  208 . If the TTL value has expired (e.g., and thus the directory entry  208  expired), then the process  300  may be stopped due to expiration thereof. In some cases, the lookup message may be forwarded to any other nodes connected to the computing node  200 , where such nodes may then perform the process  300  accordingly. 
     If, in step  310 , the computing node  200  determines that there is no directory entry  208  that has a response term that satisfies the lookup term, then, in step  316 , the validation module  218  may determine if the TTL value included in the lookup message has expired (e.g., by decrementing a time value thereof or checking an expiration time against a present time). If the TTL value has not expired, then, in step  318 , the transmitting device  220  of the computing node  200  may forward the lookup message to any additional nodes  108  in the communication network  100  that the computing node  200  has an active connection with. If the TTL value has expired, then the process  300  may be stopped. If, before the time-to-live set for the lookup message elapses, the originating node  102  has received a valid lookup response from the target node  104  then it can either connect to it asynchronously or re-use the connection over which it receives the lookup response to perform the direct exchange of transaction data required by the application. Otherwise, the originating node  102  can consider the lookup operation to have failed and/or re-try with a larger time-to-live value, depending on the requirements of the application. 
     Exemplary Method for Establishing a Connection Between Two Nodes 
       FIG.  4    illustrates a method  400  for establishing a communication channel between two nodes in a communication network without the use of a centralized directory or mapping identifiers. 
     In step  402 , a directory cache (e.g., directory cache  206 ) comprised of a plurality of directory entries (e.g., directory entries  208 ) may be stored in a memory (e.g., memory  212 ) of an intermediary node (e.g., intermediary node  106 , computing node  200 ) in a communication network (e.g., communication network  100 ), where each directory entry includes a response term, communication address, a timestamp, and an entry time-to-live value. In step  404 , a lookup message may be received by a receiver (e.g., receiving device  202 ) of the intermediary node from an originating node (e.g., originating node  102 , computing node  200 ), where the lookup message includes at least a lookup term, a network address of the originating node, and a lookup time-to-live value. In step  406 , a processor (e.g., querying module  214 ) of the intermediary node may determine if a specific entry in the directory cache stored in the intermediary node includes a response term that satisfies the lookup term. 
     If the processor determines that a specific entry includes a response term that satisfies the lookup term, then, in step  408 , a communication channel may be established by the intermediary node with a target node (e.g., target node  104 , computing node  200 ) in the communication network using the communication address included in the specific entry, and, in step  410 , the lookup message may be forwarded to the target node by a transmitter (e.g., transmitting device  220 ) of the intermediary node using the established communication channel. If, in step  406 , the processor determines that no specific entry in the directory cache includes a response term that satisfies the lookup term, then, in step  412 , the lookup message may be forwarded to a plurality of connected nodes (e.g., additional nodes  108 , computing nodes  200 ) with active communication connections to the intermediary node in the communication network by the transmitter of the intermediary node. 
     In one embodiment, the lookup message may further include an identification value associated with a lookup operation in the communication network. In some embodiments, determining that a specific entry includes a response term that satisfies the lookup term may further include determining that a time elapsed since the timestamp included in the specific entry is less than the entry time-to-live value. In one embodiment, the lookup time-to-live value in the lookup message may be decremented prior to forwarding the lookup message based on a time elapsed since receiving the lookup message. In a further embodiment, if the decremented lookup time-to-live value is below or equal to zero, the lookup message may be discarded instead of forwarded. 
     In some embodiments, the method  400  may further include inserting, by the processor of the intermediary node, a new directory entry in the directory cache that includes the lookup term, the network address, and the lookup time-to-live value from the lookup message. In one embodiment, if the processor determines that no specific entry in the directory cache includes a response term that satisfies the lookup term, then the method  400  may further include: generating, by the processor of the intermediary node, a response value; determining, by the processor of the intermediary node, that the response value satisfies the lookup term; and transmitting, by the transmitter of the intermediary node, a response message to the originating node, where the response message includes the response value and an intermediary address associated with the intermediary node in the communication network. In some embodiments, the lookup message may further include a data value, the response value may be generated via hashing the data value using a predetermined key, and the response value may satisfy the lookup term by being equivalent to the lookup term. 
     Computer System Architecture 
       FIG.  5    illustrates a computer system  500  in which embodiments of the present disclosure, or portions thereof, may be implemented as computer-readable code. For example, the originating node  102 , target node  104 , intermediary nodes  106 , and additional nodes  108  of  FIG.  1    and the computing node  200  of  FIG.  2    may be implemented in the computer system  500  using hardware, non-transitory computer readable media having instructions stored thereon, or a combination thereof and may be implemented in one or more computer systems or other processing systems. Hardware may embody modules and components used to implement the methods of  FIGS.  3  and  4   . 
     If programmable logic is used, such logic may execute on a commercially available processing platform configured by executable software code to become a specific purpose computer or a special purpose device (e.g., programmable logic array, application-specific integrated circuit, etc.). A person having ordinary skill in the art may appreciate that embodiments of the disclosed subject matter can be practiced with various computer system configurations, including multi-core multiprocessor systems, minicomputers, mainframe computers, computers linked or clustered with distributed functions, as well as pervasive or miniature computers that may be embedded into virtually any device. For instance, at least one processor device and a memory may be used to implement the above described embodiments. 
     A processor unit or device as discussed herein may be a single processor, a plurality of processors, or combinations thereof. Processor devices may have one or more processor “cores.” The terms “computer program medium,” “non-transitory computer readable medium,” and “computer usable medium” as discussed herein are used to generally refer to tangible media such as a removable storage unit  518 , a removable storage unit  522 , and a hard disk installed in hard disk drive  512 . 
     Various embodiments of the present disclosure are described in terms of this example computer system  500 . After reading this description, it will become apparent to a person skilled in the relevant art how to implement the present disclosure using other computer systems and/or computer architectures. Although operations may be described as a sequential process, some of the operations may in fact be performed in parallel, concurrently, and/or in a distributed environment, and with program code stored locally or remotely for access by single or multi-processor machines. In addition, in some embodiments the order of operations may be rearranged without departing from the spirit of the disclosed subject matter. 
     Processor device  504  may be a special purpose or a general-purpose processor device specifically configured to perform the functions discussed herein. The processor device  504  may be connected to a communications infrastructure  506 , such as a bus, message queue, network, multi-core message-passing scheme, etc. The network may be any network suitable for performing the functions as disclosed herein and may include a local area network (LAN), a wide area network (WAN), a wireless network (e.g., WiFi), a mobile communication network, a satellite network, the Internet, fiber optic, coaxial cable, infrared, radio frequency (RF), or any combination thereof. Other suitable network types and configurations will be apparent to persons having skill in the relevant art. The computer system  500  may also include a main memory  508  (e.g., random access memory, read-only memory, etc.), and may also include a secondary memory  510 . The secondary memory  510  may include the hard disk drive  512  and a removable storage drive  514 , such as a floppy disk drive, a magnetic tape drive, an optical disk drive, a flash memory, etc. 
     The removable storage drive  514  may read from and/or write to the removable storage unit  518  in a well-known manner. The removable storage unit  518  may include a removable storage media that may be read by and written to by the removable storage drive  514 . For example, if the removable storage drive  514  is a floppy disk drive or universal serial bus port, the removable storage unit  518  may be a floppy disk or portable flash drive, respectively. In one embodiment, the removable storage unit  518  may be non-transitory computer readable recording media. 
     In some embodiments, the secondary memory  510  may include alternative means for allowing computer programs or other instructions to be loaded into the computer system  500 , for example, the removable storage unit  522  and an interface  520 . Examples of such means may include a program cartridge and cartridge interface (e.g., as found in video game systems), a removable memory chip (e.g., EEPROM, PROM, etc.) and associated socket, and other removable storage units  522  and interfaces  520  as will be apparent to persons having skill in the relevant art. 
     Data stored in the computer system  500  (e.g., in the main memory  508  and/or the secondary memory  510 ) may be stored on any type of suitable computer readable media, such as optical storage (e.g., a compact disc, digital versatile disc, Blu-ray disc, etc.) or magnetic tape storage (e.g., a hard disk drive). The data may be configured in any type of suitable database configuration, such as a relational database, a structured query language (SQL) database, a distributed database, an object database, etc. Suitable configurations and storage types will be apparent to persons having skill in the relevant art. 
     The computer system  500  may also include a communications interface  524 . The communications interface  524  may be configured to allow software and data to be transferred between the computer system  500  and external devices. Exemplary communications interfaces  524  may include a modem, a network interface (e.g., an Ethernet card), a communications port, a PCMCIA slot and card, etc. Software and data transferred via the communications interface  524  may be in the form of signals, which may be electronic, electromagnetic, optical, or other signals as will be apparent to persons having skill in the relevant art. The signals may travel via a communications path  526 , which may be configured to carry the signals and may be implemented using wire, cable, fiber optics, a phone line, a cellular phone link, a radio frequency link, etc. 
     The computer system  500  may further include a display interface  502 . The display interface  502  may be configured to allow data to be transferred between the computer system  500  and external display  530 . Exemplary display interfaces  502  may include high-definition multimedia interface (HDMI), digital visual interface (DVI), video graphics array (VGA), etc. The display  530  may be any suitable type of display for displaying data transmitted via the display interface  502  of the computer system  500 , including a cathode ray tube (CRT) display, liquid crystal display (LCD), light-emitting diode (LED) display, capacitive touch display, thin-film transistor (TFT) display, etc. 
     Computer program medium and computer usable medium may refer to memories, such as the main memory  508  and secondary memory  510 , which may be memory semiconductors (e.g., DRAMs, etc.). These computer program products may be means for providing software to the computer system  500 . Computer programs (e.g., computer control logic) may be stored in the main memory  508  and/or the secondary memory  510 . Computer programs may also be received via the communications interface  524 . Such computer programs, when executed, may enable computer system  500  to implement the present methods as discussed herein. In particular, the computer programs, when executed, may enable processor device  504  to implement the methods illustrated by  FIGS.  3  and  4   , as discussed herein. Accordingly, such computer programs may represent controllers of the computer system  500 . Where the present disclosure is implemented using software, the software may be stored in a computer program product and loaded into the computer system  500  using the removable storage drive  514 , interface  520 , and hard disk drive  512 , or communications interface  524 . 
     The processor device  504  may comprise one or more modules or engines configured to perform the functions of the computer system  500 . Each of the modules or engines may be implemented using hardware and, in some instances, may also utilize software, such as corresponding to program code and/or programs stored in the main memory  508  or secondary memory  510 . In such instances, program code may be compiled by the processor device  504  (e.g., by a compiling module or engine) prior to execution by the hardware of the computer system  500 . For example, the program code may be source code written in a programming language that is translated into a lower level language, such as assembly language or machine code, for execution by the processor device  504  and/or any additional hardware components of the computer system  500 . The process of compiling may include the use of lexical analysis, preprocessing, parsing, semantic analysis, syntax-directed translation, code generation, code optimization, and any other techniques that may be suitable for translation of program code into a lower level language suitable for controlling the computer system  500  to perform the functions disclosed herein. It will be apparent to persons having skill in the relevant art that such processes result in the computer system  500  being a specially configured computer system  500  uniquely programmed to perform the functions discussed above. 
     Techniques consistent with the present disclosure provide, among other features, systems and methods for establishing a connection between two nodes in a communication network without use of a centralized directory or mapping identifiers. While various exemplary embodiments of the disclosed system and method have been described above it should be understood that they have been presented for purposes of example only, not limitations. It is not exhaustive and does not limit the disclosure to the precise form disclosed. Modifications and variations are possible in light of the above teachings or may be acquired from practicing of the disclosure, without departing from the breadth or scope.