Patent Description:
A pseudo-random sequence of bits (often termed "entropy") is often used in order to generate (or even as) a cryptographic key. The use of a pseudo-randomly generated bit sequence as the cryptographic key is advantageous as it makes the cryptographic key difficult to guess. That is important because if the cryptographic key is guessed, that cryptographic key may be used to improperly obtain data. Furthermore, if the cryptographic key is used to authenticate (e.g., in a digital signature), the cryptographic key could be used to impersonate another entity, or tamper with a message without detection.

Rather, this background is only provided to illustrate one exemplary technology area where some embodiments describe herein may be practiced. <CIT> discloses programmatic interfaces that may be implemented by a service providing selectable-quality random data. As shown, two broad categories of programmatic interfaces may be implemented: configuration and control interfaces, and request and delivery interfaces. Configuration/control interfaces may allow service clients, e.g., administrators or other authorized users of the random-data consuming applications, or the applications themselves, to specify preferences or requirements regarding various characteristics of the random data to be provided. One set of programmatic interfaces may be used to obtain the random data from the service by an intermediary component such as a local aggregator in such an implementation, while a different set of interfaces may be used for providing the random data to client applications from the intermediary, and no modifications may be needed to the client applications in such implementations. <CIT> discloses a system in which the security of the random numbers provided to respective consumers may be enhanced using techniques selected based at least in part on the contexts in which the random numbers are to be used. The system comprises an entropy source pool, a pseudo-random number (PRN) generator pool, and a PRN security enhancer (PSE). The PSE may implement one or more programmatic interfaces, such as web-services interfaces, which may be used by a plurality of clients to submit requests for PRNs or for data artifacts that are constructed using PRNs, and/or to receive the corresponding response PRNs or artifacts. The PSE may apply some combination of one or more security enhancement mechanisms to generate the PRNs in the depicted embodiment, with the overall goal of preventing any of the clients from being able to make useful predictions regarding PRNs that have been (or will be) provided to any of the other clients. It is the object of the present invention to provide an alternative solution to <CIT>'s solution to provide high-quality randomness to a user for a key generation mechanism.

Embodiments disclosed herein relate to the generation of a cryptographic key using one of multiple possible entropy generation components that may provide input entropy. A key generation component provides an interface that exposes a set of one or more characteristics for input entropy to be used to generate a cryptographic key. For applications that are more sensitive to improper key discovery, higher degrees of input entropy may be used to guard against key discovery. For applications that are less sensitive to key discovery, a relatively lower degree of input entropy may be used so that keys may be conveniently generated without the rigorous processing and/or time used to generate higher degrees of input entropy.

During key generation, the key generation component connects with an appropriate entropy generation component via the interface. For instance, the entropy generation component may be selected or adjusted so that it does indeed provide the input entropy meeting the characteristics described by the interface. The key generation component receives the input entropy via the interface, and then uses the input entropy to generate the cryptographic key.

<FIG> illustrates an environment <NUM> in which the principles described herein may be employed. The environment <NUM> includes a key generation component <NUM>, a library of entropy generation components <NUM>, and an entropy generation component selection component <NUM>.

The key generation component <NUM> may be operated upon a computing system such as the computing system <NUM> described below with respect to <FIG>. In that case, the key generation component <NUM> may be structured as described for the executable component <NUM> of <FIG>. The key generation component <NUM> generates cryptographic keys (such as cryptographic keys <NUM> and <NUM>).

Such cryptographic keys may include encryption keys that may be used by an encryption algorithm to transform (i.e., encrypt) plain data into encrypted data (i.e., "cipher data"). Alternatively, or in addition, such cryptographic keys may include decryption keys that may be used by a decryption algorithm to transform (i.e., decrypt) cipher data into plain data. Here, "cipher data" is data that can only be interpreted after decryption, whereas "plain data" is data that can be interpreted without decryption. Such data may be any structured data, but is often text. In that case, the plain data is often termed "plain text,", and the cipher data is often termed "cipher text. " Typically, plain text can be read by a human being to extract meaning, whereas cipher text cannot.

The key generation component <NUM> provides an interface <NUM> that exposes one or more characteristics (as represented by arrow) <NUM> of input entropy that is to be used by the key generation component <NUM> in order to generate a cryptographic key. The input entropy is a pseudo-random sequence of bits. The use of a pseudo-randomly generated bit sequence as the cryptographic key is advantageous as it makes the cryptographic key difficult to guess. That is important because if the cryptographic key is guessed, that cryptographic key may be used to improperly obtain data. The input entropy may even be used as the cryptographic key itself without any further transformation.

The set of one or more cryptographic key input entropy characteristics <NUM> may be specific to a particular application that will use the cryptographic key, and/or the specific context in which the cryptographic key will be used. For instance, if there is one application (a "first" application) that will use the cryptographic key, there may be one set of input entropy characteristics <NUM> that are exposed by the interface <NUM>. If there is another application (a "second" application) that will use the cryptographic key, there may be another set of input entropy characteristics <NUM> that are exposed by the interface <NUM>.

In a specific example of this, if the application is a wallet that holds and encrypts claims issued to a decentralized identifier by a national security agency indicating a level of national security clearance issued for the user associated with the decentralized identifier, the level of input entropy would be high to prevent someone from changing that critical claim. On the other hand, if the wallet holds a claim regarding membership in a hobby club, or whether library dues have been paid, then the input entropy might be much lower.

As another example in which the context in which the cryptographic key will be used is factored into the level of input entropy, there is the consideration of whether the cryptographic key is a master cryptographic key or a derived cryptographic key. If a master cryptographic key is being generated, more rigorous input entropy may be generated, since correctly guessing the master cryptographic key may lead not only to discovery of that master cryptographic key, but also potentially the discovery of derived cryptographic keys that have been derived from that master cryptographic key. On the other hand, if a derived cryptographic key is being generated, then the input entropy level may be reduced since guessing that derived cryptographic key would result in more contained harm. More generally speaking, the input entropy used to generate one cryptographic key (a "parent" cryptographic key) may be at a higher level than the entropy used to generate another cryptographic key (a "child" cryptographic key) that was derived from that parent cryptographic key.

Thus, the set of input entropy characteristics <NUM> may depend on the application that will use the cryptographic key and/or the context in which the cryptographic key will be used. Furthermore, if the key generation component <NUM> generates cryptographic keys for different applications and/or contexts, the exposed input entropy characteristics <NUM> may change depending on which application and/or context for which the current cryptographic key is being generated.

The set of one of more cryptographic key input entropy characteristics exposed by the interface may be any characteristic of the input entropy. As an example, the characteristic could be a size of the input entropy. For instance, the size of the input entropy could be <NUM> bits, <NUM> bits, <NUM> bits, <NUM> bits, and so on. Generally, the larger the input entropy, the harder it is to guess the corresponding cryptographic key. As another characteristic, there might be the type of input entropy or, in other words, an identification of an algorithm for generating the entropy. There may also be a specified minimum or maximum time for generating the entropy. There may also be a specified level of entropy (e.g., a number of iterations to be used to generate the entropy, and a level of randomness). There may also be a seed to be used to generate the entropy. For instance, background radiation from the birth of the universe is a very random seed to use in generating input entropy, which is even more random than rolling dice.

The environment <NUM> includes a library <NUM> of entropy generation components. For instance, the library <NUM> is illustrated as including five entropy generation components <NUM> to <NUM>, though the ellipsis <NUM> represents that the library <NUM> may include any number of entropy generation components. Each of the entropy generation components <NUM> is capable of generating input entropy for use in generating a cryptographic key. The library <NUM> may be operated upon a computing system, such as the computing system <NUM> described below with respect to <FIG>. In that case, each of the components <NUM> may be structured as described below with respect to the executable component <NUM> of <FIG>.

The entropy generation components <NUM> through <NUM> may be provided separate from the application that runs the key generation component <NUM>. For instance, one or more of the entropy generation components <NUM> through <NUM> may be provided by a user or third-party source. Alternatively, or in addition, one or more of the entropy generation components may be provided by an application that will use the cryptographic key being generated (e.g., a wallet of a decentralized identifier).

The entropy generation component selection component <NUM> is capable of interpreting the one or more characteristics <NUM> of input entropy that is to be used by the key generation component <NUM>, and selects an appropriate one of the entropy generation components <NUM> that is capable of providing input entropy having those characteristic(s) <NUM>. The entropy generation component selection component <NUM> may be operated upon a computing system, such as the computing system <NUM> described below with respect to <FIG>. In that case, the entropy generation component selection component <NUM> may be structured as described below with respect to the executable component <NUM> of <FIG>.

The entropy generation component selection component <NUM> connects the selected entropy generation component to the interface <NUM>, where the selected entropy generation component may then provide the input entropy via the interface <NUM> to the key generation component <NUM>. For instance, the entropy generation component selection component <NUM> may establish a direct connection (via the interface <NUM>) between the key generation component and the selected entropy generation component. As another example of a connection, the entropy generation component selection component <NUM> may cause the selected entropy generation component to run, and then pass the resulting input entropy to the key generation component <NUM> via the interface <NUM>.

The key generation component <NUM>, each of the entropy generation components <NUM>, and the entropy generation component selection component <NUM> and may be operated upon the same computing system. At the other extreme, each of the key generation component <NUM>, the entropy generation components <NUM>, and the entropy generation component selection component <NUM> may be operated by different computing systems. However, the principles described herein are not restricted to whether the environment <NUM> is provided by a single computing system, or distributed across multiple computing systems. Furthermore, the principles described herein are not limited to the number of the illustrated components that are executed by any given computing system. Nevertheless, the interface <NUM> permits the input entropy to be separately generated and then provided through the interface for use in cryptographic key generation.

<FIG> illustrates a flowchart of a method <NUM> for generating a cryptographic key, in accordance with the principles described herein. This is done by connecting with one of multiple possible entropy generation components that may provide input entropy to be used for generating the cryptographic key. The method <NUM> may be operated within the environment <NUM> of <FIG>. For instance, the entropy generation component selection component <NUM> may connect the appropriate selected entropy generation component <NUM> (e.g., entropy generation component <NUM>) so that the selected entropy generation component may provide input entropy through the interface <NUM> to the key generation component <NUM>, whereby the key generation component <NUM> may generate the key <NUM> using that input entropy. Accordingly, the method <NUM> of <FIG> will now be described with frequent reference to the environment <NUM> of <FIG>.

The method <NUM> includes providing an interface that exposes a set of one or more cryptographic key input entropy characteristics for input entropy to be used to generate a cryptographic key (act <NUM>). For instance, with reference to <FIG>, the key generation component <NUM> offers the interface <NUM> that exposes the one of more cryptographic key input entropy characteristics <NUM> for input entropy to be used in generating the cryptographic key <NUM>.

The method <NUM> then includes connecting with a selected entropy component via the interface (act <NUM>). In one embodiment, this may be performed by selecting the entropy generation component from the library of entropy generation components (act <NUM>), and then causing the selected entropy generation component to be connected via the interface to a key generation component (act <NUM>). For instance, in <FIG>, the input entropy generation component selection component <NUM> might select the input entropy generation component <NUM>, and then cause that selected input entropy generation component <NUM> to be connected to the interface <NUM>. This selection is represented by arrow <NUM> in <FIG>.

The method <NUM> then includes the key generation component receives, via the interface, input entropy from the selected entropy generation component (act <NUM>). For instance, in <FIG>, as a result of being selected, the selected entropy generation component <NUM> provides (as represented by arrow <NUM>) the entropy through the interface <NUM> to the key generation component <NUM>.

The key generation component then generates the cryptographic key using the received input entropy (act <NUM>). For instance, the key generation component <NUM> may generate (as represented by arrow <NUM>) the cryptographic key <NUM> using the input entropy provided (as represented by the arrow <NUM>).

Accordingly, the principles provide a level of distributed control in generating cryptographic keys. The cryptographic key generator still is able to control a minimum standard for generating input entropy, without having to generating the input entropy itself. Instead, the key generation component may use a wide variety of input entropy generators as the circumstances warrant.

Because the principles described herein may be performed in the context of a computing system, some introductory discussion of a computing system will be described with respect to <FIG>. Then, because the key generation may be performed in the context of a decentralized identifier wallet (or management module) that is used to encrypt claims having the decentralized identifier as a subject, a decentralized identity framework environment will thereafter be described with respect to <FIG>.

As illustrated in <FIG>, in its most basic configuration, a computing system <NUM> typically includes at least one hardware processing unit <NUM> and memory <NUM>. The processing unit <NUM> may include a general-purpose processor and may also include a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), or any other specialized circuit. The memory <NUM> may be physical system memory, which may be volatile, non-volatile, or some combination of the two. The term "memory" may also be used herein to refer to non-volatile mass storage such as physical storage media. If the computing system is distributed, the processing, memory and/or storage capability may be distributed as well.

The computing system <NUM> also has thereon multiple structures often referred to as an "executable component". For instance, the memory <NUM> of the computing system <NUM> is illustrated as including executable component <NUM>. The term "executable component" is the name for a structure that is well understood to one of ordinary skill in the art in the field of computing as being a structure that can be software, hardware, or a combination thereof. For instance, when implemented in software, one of ordinary skill in the art would understand that the structure of an executable component may include software objects, routines, methods, and so forth, that may be executed on the computing system, whether such an executable component exists in the heap of a computing system, or whether the executable component exists on computer-readable storage media.

In such a case, one of ordinary skill in the art will recognize that the structure of the executable component exists on a computer-readable medium such that, when interpreted by one or more processors of a computing system (e.g., by a processor thread), the computing system is caused to perform a function. Such structure may be computer readable directly by the processors (as is the case if the executable component were binary). Alternatively, the structure may be structured to be interpretable and/or compiled (whether in a single stage or in multiple stages) so as to generate such binary that is directly interpretable by the processors. Such an understanding of example structures of an executable component is well within the understanding of one of ordinary skill in the art of computing when using the term "executable component".

While not all computing systems require a user interface, in some embodiments, the computing system <NUM> includes a user interface system <NUM> for use in interfacing with a user. The user interface system <NUM> may include output mechanisms 312A as well as input mechanisms 312B. The principles described herein are not limited to the precise output mechanisms 312A or input mechanisms 312B as such will depend on the nature of the device. However, output mechanisms 312A might include, for instance, speakers, displays, tactile output, virtual or augmented reality, holograms and so forth. Examples of input mechanisms 312B might include, for instance, microphones, touchscreens, virtual or augmented reality, holograms, cameras, keyboards, mouse or other pointer input, sensors of any type, and so forth.

The remaining figures may discuss various computing system which may correspond to the computing system <NUM> previously described. The computing systems of the remaining figures include various components or functional blocks that may implement the various embodiments disclosed herein as will be explained. The various components or functional blocks may be implemented on a local computing system or may be implemented on a distributed computing system that includes elements resident in the cloud or that implement aspects of cloud computing. The various components or functional blocks may be implemented as software, hardware, or a combination of software and hardware. The computing systems of the remaining figures may include more or less than the components illustrated in the figures and some of the components may be combined as circumstances warrant.

Some introductory discussion of a decentralized identifier (DID) and the environment in which they are created and reside will now be given with respect to <FIG>. As illustrated in <FIG>, a DID owner <NUM> may own or control a DID <NUM> that represents an identity of the DID owner <NUM>. The DID owner <NUM> may register a DID using a creation and registration service, which will be explained in more detail below.

The DID owner <NUM> may be any entity that could benefit from a DID. For example, the DID owner <NUM> may be a human being or an organization of human beings. Such organizations might include a company, department, government, agency, or any other organization or group of organizations. Each individual human being might have a DID while the organization(s) to which each belongs might likewise have a DID.

The DID owner <NUM> may alternatively be a machine, system, or device, or a collection of machine(s), device(s) and/or system(s). In still other embodiments, the DID owner <NUM> may be a subpart of a machine, system or device. For instance, a device could be a printed circuit board, where the subpart of that circuit board are individual components of the circuit board. In such embodiments, the machine or device may have a DID and each subpart may also have a DID. A DID owner might also be a software component such as the executable component <NUM> described above with respect to <FIG>. An example of a complex executable component <NUM> might be an artificial intelligence. Accordingly, an artificial intelligence may also own a DID.

Thus, the DID owner <NUM> may be any entity, human or non-human, that is capable of creating the DID <NUM> or at least having the DID <NUM> created for and/or associated with them. Although the DID owner <NUM> is shown as having a single DID <NUM>, this need not be the case as there may be any number of DIDs associated with the DID owner <NUM> as circumstances warrant.

As mentioned, the DID owner <NUM> may create and register the DID <NUM>. The DID <NUM> may be any identifier that may be associated with the DID owner <NUM>. Preferably, that identifier is unique to that DID owner <NUM>, at least within a scope in which the DID is anticipated to be in use. As an example, the identifier may be a locally unique identifier, and perhaps more desirably a globally unique identifier for identity systems anticipated to operate globally. In some embodiments, the DID <NUM> may be a Uniform Resource identifier (URI) (such as a Uniform Resource Locator (URL)) or other pointer that relates the DID owner <NUM> to mechanisms to engage in trustable interactions with the DID owner <NUM>.

The DID <NUM> is "decentralized" because it does not require a centralized, third party management system for generation, management, or use. Accordingly, the DID <NUM> remains under the control of the DID owner <NUM>. This is different from conventional centralized IDs which base trust on centralized authorities and that remain under control of corporate directory services, certificate authorities, domain name registries, or other centralized authority (referred to collectively as "centralized authorities" herein). Accordingly, the DID <NUM> may be any identifier that is under the control of the DID owner <NUM> and that is independent of any centralized authority.

In some embodiments, the structure of the DID <NUM> may be as simple as a user name or some other human-understandable term. However, in other embodiments, for increased security, the DID <NUM> may preferably be a random string of numbers and letters. In one embodiment, the DID <NUM> may be a string of <NUM> numbers and letters. Accordingly, the embodiments disclosed herein are not dependent on any specific implementation of the DID <NUM>. In a very simple example, the DID <NUM> is shown within the figures as "123ABC".

As also shown in <FIG>, the DID owner <NUM> has control of a private key <NUM> and public key <NUM> pair that is associated with the DID <NUM>. Because the DID <NUM> is independent of any centralized authority, the private key <NUM> should at all times be fully in control of the DID owner <NUM>. That is, the private and public keys should be generated in a decentralized manner that ensures that they remain under the control of the DID owner <NUM>.

As will be described in more detail to follow, the private key <NUM> and public key <NUM> pair may be generated on a device controlled by the DID owner <NUM>. The private key <NUM> and public key <NUM> pair should not be generated on a server controlled by any centralized authority as this may cause the private key <NUM> and public key <NUM> pair to not be fully under the control of the DID owner <NUM> at all times. Although <FIG> and this description have described a private and public key pair, it will also be noted that other types of reasonable cryptographic information and/or mechanisms may also be used as circumstances warrant.

<FIG> also illustrates a DID document <NUM> that is associated with the DID <NUM>. As will be explained in more detail to follow, the DID document <NUM> may be generated at the time that the DID <NUM> is created. In its simplest form, the DID document <NUM> describes how to use the DID <NUM>. Accordingly, the DID document <NUM> includes a reference to the DID <NUM>, which is the DID that is described by the DID document <NUM>. In some embodiments, the DID document <NUM> may be implemented according to methods specified by a distributed ledger <NUM> (such as blockchain) that will be used to store a representation of the DID <NUM> as will be explained in more detail to follow. Thus, the DID document <NUM> may have different methods depending on the specific distributed ledger.

The DID document <NUM> also includes the public key <NUM> created by the DID owner <NUM> or some other equivalent cryptographic information. The public key <NUM> may be used by third party entities that are given permission by the DID owner <NUM> to access information and data owned by the DID owner <NUM>. The public key <NUM> may also be used to verify that the DID owner <NUM> in fact owns or controls the DID <NUM>.

The DID document <NUM> may also include authentication information <NUM>. The authentication information <NUM> may specify one or more mechanisms by which the DID owner <NUM> is able to prove that the DID owner <NUM> owns the DID <NUM>. In other words, the mechanisms of the authentication information <NUM> may show proof of a binding between the DID <NUM> (and thus its DID owner <NUM>) and the DID document <NUM>. In one embodiment, the authentication information <NUM> may specify that the public key <NUM> be used in a signature operation to prove the ownership of the DID <NUM>. Alternatively, or in addition, the authentication information <NUM> may specify that the public key <NUM> be used in a biometric operation to prove ownership of the DID <NUM>. Accordingly, the authentication information <NUM> may include any number of mechanisms by which the DID owner <NUM> is able to prove that the DID owner <NUM> owns the DID <NUM>.

The DID document <NUM> may also include authorization information <NUM>. The authorization information <NUM> may allow the DID owner <NUM> to authorize third party entities the rights to modify the DID document <NUM> or some part of the document without giving the third party the right to prove ownership of the DID <NUM>. For example, the authorization information <NUM> may allow the third party to update any designated set of one or more fields in the DID document <NUM> using any designated update mechanism. Alternatively, the authorization information may allow the third party to limit the usages of DID <NUM> by the DID owner <NUM> for a specified time period. This may be useful when the DID owner <NUM> is a minor child and the third party is a parent or guardian of the child. The authorization information <NUM> may allow the parent or guardian to limit use of the DID owner <NUM> until such time as the child is no longer a minor.

The authorization information <NUM> may also specify one or more mechanisms that the third party will need to follow to prove they are authorized to modify the DID document <NUM>. In some embodiments, these mechanisms may be similar to those discussed previously with respect to the authentication information <NUM>.

The DID document <NUM> may also include one or more service endpoints <NUM>. A service endpoint may include a network address at which a service operates on behalf of the DID owner <NUM>. Examples of specific services include discovery services, social networks, file storage services such as identity servers or hubs, and verifiable claim repository services. Accordingly, the service endpoints <NUM> operate as pointers for the services that operate on behalf of the DID owner <NUM>. These pointers may be used by the DID owner <NUM> or by third party entities to access the services that operate on behalf of the DID owner <NUM>. Specific examples of service endpoints <NUM> will be explained in more detail to follow.

The DID document <NUM> may further include identification information <NUM>. The identification information <NUM> may include personally identifiable information such as the name, address, occupation, family members, age, hobbies, interests, or the like of DID owner <NUM>. Accordingly, the identification information <NUM> listed in the DID document <NUM> may represent a different persona of the DID owner <NUM> for different purposes.

A persona may be pseudo anonymous. As an example, the DID owner <NUM> may include a pen name in the DID document when identifying him or her as a writer posting articles on a blog. A persona may be fully anonymous. As an example, the DID owner <NUM> may only want to disclose his or her job title or other background data (e.g., a school teacher, an FBI agent, an adult older than <NUM> years old, etc.) but not his or her name in the DID document. As yet another example, a persona may be specific to who the DID owner <NUM> is as an individual. As an example, the DID owner <NUM> may include information identifying him or her as a volunteer for a particular charity organization, an employee of a particular corporation, an award winner of a particular award, and so forth.

The DID document <NUM> may also include credential information <NUM>, which may also be referred to herein as an attestation. The credential information <NUM> may be any information that is associated with the DID owner <NUM>'s background. For instance, the credential information <NUM> may be (but not limited to) a qualification, an achievement, a government ID, a government right such as a passport or a driver's license, a payment provider or bank account, a university degree or other educational history, employment status and history, or any other information about the DID owner <NUM>'s background.

The DID document <NUM> may also include various other information <NUM>. In some embodiments, the other information <NUM> may include metadata specifying when the DID document <NUM> was created and/or when it was last modified. In other embodiments, the other information <NUM> may include cryptographic proofs of the integrity of the DID document <NUM>. In still further embodiments, the other information <NUM> may include additional information that is either specified by the specific method implementing the DID document or desired by the DID owner <NUM>.

<FIG> also illustrates a distributed ledger <NUM>. The distributed ledger <NUM> may be any decentralized, distributed network that includes various computing systems that are in communication with each other. For example, the distributed ledger <NUM> may include a first distributed computing system <NUM>, a second distributed computing system <NUM>, a third distributed computing system <NUM>, and any number of additional distributed computing systems as illustrated by the ellipses <NUM>. The distributed ledger <NUM> may operate according to any known standards or methods for distributed ledgers. Examples of conventional distributed ledgers that may correspond to the distributed ledger <NUM> include, but are not limited to, Bitcoin [BTC], Ethereum, and Litecoin.

In the context of DID <NUM>, the distributed ledger or blockchain <NUM> is used to store a representation of the DID <NUM> that points to the DID document <NUM>. In some embodiments, the DID document <NUM> may be stored on the actual distributed ledger. Alternatively, in other embodiments the DID document <NUM> may be stored in a data storage (not illustrated) that is associated with the distributed ledger <NUM>.

As mentioned, a representation of the DID <NUM> is stored on each distributed computing system of the distributed ledger <NUM>. For example, in <FIG> this is shown as DID hash <NUM>, DID hash <NUM>, and DID hash <NUM>, which are ideally identical hashed copies of the same DID. The DID hash <NUM>, DID hash <NUM>, and DID hash <NUM> may then point to the location of the DID document <NUM>. The distributed ledger or blockchain <NUM> may also store numerous other representations of other DIDs as illustrated by references <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM>.

In one embodiment, when the DID owner <NUM> creates the DID <NUM> and the associated DID document <NUM>, the DID hash <NUM>, DID hash <NUM>, and DID hash <NUM> are written to the distributed ledger <NUM>. The distributed ledger <NUM> thus records that the DID <NUM> now exists. Since the distributed ledger <NUM> is decentralized, the DID <NUM> is not under the control of any entity outside of the DID owner <NUM>. DID hash <NUM>, DID hash <NUM>, and DID hash <NUM> may each include, in addition to the pointer to the DID document <NUM>, a record or time stamp that specifies when the DID <NUM> was created. At a later date, when modifications are made to the DID document <NUM>, each modification (and potentially also a timestamp of the modification) may also be recorded in DID hash <NUM>, DID hash <NUM>, and DID hash <NUM>. DID hash <NUM>, DID hash <NUM>, and DID hash <NUM> may further include a copy of the public key <NUM> so that the DID <NUM> is cryptographically bound to the DID document <NUM>.

Having described DIDs and how they operate generally with reference to <FIG>, specific embodiments of DID environments will now be explained. Turning to <FIG>, an environment <NUM> that may be used to perform various DID management operations and services will now be explained. It will be appreciated that the environment of <FIG> may reference elements from <FIG> as needed for ease of explanation.

As shown in <FIG>, the environment <NUM> may include various devices and computing systems that may be owned or otherwise under the control of the DID owner <NUM>. These may include a user device <NUM>. The user device <NUM> may be, but is not limited to, a mobile device such as a smart phone, a computing device such as a laptop computer, or any device such as a car or an appliance that includes computing abilities. The device <NUM> may include a web browser <NUM> operating on the device and an operating system <NUM> operating the device. More broadly speaking, the dashed line <NUM> represents that all of these devices may be owned or otherwise under the control of the DID owner <NUM>.

The environment <NUM> also includes a DID management module <NUM>. It will be noted that in operation, the DID management module <NUM> may reside on and be executed by one or more of user device <NUM>, web browser <NUM>, and the operating system <NUM> as illustrated by respective lines 501a, 502a, and 503a. Accordingly, the DID management module <NUM> is shown as being separate for ease of explanation. The DID management module <NUM> may be also described as a "wallet" in that it can hold various claims related to a particular DID. The DID management module <NUM> may also be described as a "user agent".

As shown in <FIG>, the DID management module <NUM> includes a DID creation module <NUM>. The DID creation module <NUM> may be used by the DID owner <NUM> to create the DID <NUM> or any number of additional DIDs, such as DID <NUM>. In one embodiment, the DID creation module may include or otherwise have access to a User Interface (UI) element <NUM> that may guide the DID owner <NUM> in creating the DID <NUM>. The DID creation module <NUM> may have one or more drivers that are configured to work with specific distributed ledgers such as distributed ledger <NUM> so that the DID <NUM> complies with the underlying methods of that distributed ledger.

A specific embodiment will now be described. For example, the UI <NUM> may provide a prompt for the user to enter a user name or some other human recognizable name. This name may be used as a display name for the DID <NUM> that will be generated. As previously described, the DID <NUM> may be a long string of random numbers and letters and so having a human-recognizable name for a display name may be advantageous. The DID creation module <NUM> may then generate the DID <NUM>. In the embodiments having the UI <NUM>, the DID <NUM> may be shown in a listing of identities and may be associated with the human-recognizable name.

The DID creation module <NUM> may also include a key generation component <NUM>. The key generation component may generate the private key <NUM> and public key <NUM> pair previously described. The DID creation module <NUM> may then use the DID <NUM> and the private and public key pair to generate the DID document <NUM>.

In operation, the DID creation module <NUM> accesses a registrar <NUM> that is configured to the specific distributed ledger that will be recording the transactions related to the DID <NUM>. The DID creation module <NUM> uses the registrar <NUM> to record DID hash <NUM>, DID hash <NUM>, and DID hash <NUM> in the distributed ledger in the manner previously described, and to store the DID document <NUM> in the manner previously described. This process may use the public key <NUM> in the hash generation.

In some embodiments, the DID management module <NUM> may include an ownership module <NUM>. The ownership module <NUM> may provide mechanisms that ensure that the DID owner <NUM> is in sole control of the DID <NUM>. In this way, the provider of the DID management module <NUM> is able to ensure that the provider does not control the DID <NUM>, but is only providing the management services.

As previously discussed, the key generation component <NUM> generates the private key <NUM> and public key <NUM> pair and the public key <NUM> is then recorded in the DID document <NUM>. Accordingly, the public key <NUM> may be used by all devices associated with the DID owner <NUM> and all third parties that desire to provide services to the DID owner <NUM>. Accordingly, when the DID owner <NUM> desires to associate a new device with the DID <NUM>, the DID owner <NUM> may execute the DID creation module <NUM> on the new device. The DID creation module <NUM> may then use the registrar <NUM> to update the DID document <NUM> to reflect that the new device is now associated with the DID <NUM>, which update would be reflected in a transaction on the distributed ledger <NUM>, as previously described.

In some embodiments, however, it may be advantageous to have a public key per device <NUM> owned by the DID owner <NUM> as this may allow the DID owner <NUM> to sign with the device-specific public key without having to access a general public key. In other words, since the DID owner <NUM> will use different devices at different times (for example using a mobile phone in one instance and then using a laptop computer in another instance), it is advantageous to have a key associated with each device to provide efficiencies in signing using the keys. Accordingly, in such embodiments the key generation component <NUM> may generate additional public keys <NUM> and <NUM> when the additional devices execute the DID creation module <NUM>. These additional public keys may be associated with the private key <NUM> or in some instances may be paired with a new private key.

In those embodiments where the additional public keys <NUM> and <NUM> are associated with different devices, the additional public keys <NUM> and <NUM> may be recorded in the DID document <NUM> as being associated with those devices. This is shown in <FIG>. It will be appreciated that the DID document <NUM> may include the information (information <NUM>, <NUM> and <NUM> through <NUM>) previously described in relation to <FIG> in addition to the information (information <NUM>, <NUM> and <NUM>) shown in <FIG>. If the DID document <NUM> existed prior to the device-specific public keys being generated, then the DID document <NUM> would be updated by the creation module <NUM> via the registrar <NUM> and this would be reflected in an updated transaction on the distributed ledger <NUM>.

In some embodiments, the DID owner <NUM> may desire to keep secret the association of a device with a public key or the association of a device with the DID <NUM>. Accordingly, the DID creation module <NUM> may cause that such data be secretly shown in the DID document <NUM>.

As described thus far, the DID <NUM> has been associated with all the devices under the control of the DID owner <NUM>, even when the devices have their own public keys. However, in some embodiments it may be useful for each device or some subset of devices under the control of the DID owner <NUM> to each have their own DID. Thus, in some embodiments the DID creation module <NUM> may generate an additional DID, for example DID <NUM>, for each device. The DID creation module <NUM> would then generate private and public key pairs and DID documents for each of the devices and have them recorded on the distributed ledger <NUM> in the manner previously described. Such embodiments may be advantageous for devices that may change ownership as it may be possible to associate the device-specific DID to the new owner of the device by granting the new owner authorization rights in the DID document and revoking such rights from the old owner.

As mentioned, to ensure that the private key <NUM> is totally in the control of the DID owner <NUM>, the private key <NUM> is created on the user device <NUM>, browser <NUM>, or operating system <NUM> that is owned or controlled by the DID owner <NUM> that executed the DID management module <NUM>. In this way, there is little chance that a third party (and most consequentially, the provider of the DID management module <NUM>) may gain control of the private key <NUM>.

However, there is a chance that the device storing the private key <NUM> may be lost by the DID owner <NUM>, which may cause the DID owner <NUM> to lose access to the DID <NUM>. Accordingly, in some embodiments, the UI <NUM> may include the option to allow the DID owner <NUM> to export the private key <NUM> to an off device secured database <NUM> that is under the control of the DID owner <NUM>. As an example, the database <NUM> may be one of the identity hubs <NUM> described below with respect to <FIG>. A storage module <NUM> is configured to store data (such as the private key <NUM> or attestations made by or about the DID owner <NUM>) off device in the database <NUM> or identity hubs <NUM>. In some embodiments, the private key <NUM> may be stored as a QR code that may be scanned by the DID owner <NUM>.

In other embodiments, the DID management module <NUM> may include a recovery module <NUM> that may be used to recover a lost private key <NUM>. In operation, the recovery module <NUM> allows the DID owner <NUM> to select one or more recovery mechanisms <NUM> at the time the DID <NUM> is created that may later be used to recover the lost private key. In those embodiments having the UI <NUM>, the UI <NUM> may allow the DID owner <NUM> to provide information that will be used by the one or more recovery mechanisms <NUM> during recovery. The recovery module <NUM> may then be run on any device associated with the DID <NUM>.

The DID management module <NUM> may also include a revocation module <NUM> that is used to revoke or sever a device from the DID <NUM>. In operation, the revocation module may use the UI element <NUM>, which may allow the DID owner <NUM> to indicate a desire to remove a device from being associated with the DID <NUM>. In one embodiment, the revocation module <NUM> may access the DID document <NUM> and may cause that all references to the device be removed from the DID document <NUM>. Alternatively, the public key for the device may be removed. This change in the DID document <NUM> may then be reflected as an updated transaction on the distributed ledger <NUM> as previously described.

<FIG> illustrates an embodiment of an environment <NUM> in which a DID such as DID <NUM> may be utilized. Specifically, the environment <NUM> will be used to describe the use of the DID <NUM> in relation to one or more decentralized stores or identity hubs <NUM> that are each under the control of the DID owner <NUM> to store data belonging to or regarding the DID owner <NUM>. For instance, data may be stored within the identity hubs using the storage module <NUM> of <FIG>. It will be noted that <FIG> may include references to elements first discussed in relation to <FIG> or <FIG> and thus use the same reference numeral for ease of explanation.

In one embodiment, the identity hubs <NUM> may be multiple instances of the same identity hub. This is represented by the line 610A. Thus, the various identity hubs <NUM> may include at least some of the same data and services. Accordingly, if a change is made to part of at least some of the data (and potentially any part of any of the data) in one of the identity hubs <NUM>, the change may be reflected in one or more of (and perhaps all of) the remaining identity hubs.

The identity hubs <NUM> may be any data store that may be in the exclusive control of the DID owner <NUM>. As an example only, the first identity hub <NUM> and second identity hub <NUM> are implemented in cloud storage (perhaps within the same cloud, or even on different clouds managed by different cloud providers) and thus may be able to hold a large amount of data. Accordingly, a full set of the data may be stored in these identity hubs.

However, the identity hubs <NUM> and <NUM> may have less memory space. Accordingly, in these identity hubs a descriptor of the data stored in the first and second identity hubs may be included. Alternatively, a record of changes made to the data in other identity hubs may be included. Thus, changes in one of the identity hubs <NUM> are either fully replicated in the other identity hubs or at least a record or descriptor of that data is recorded in the other identity hubs.

Because the identity hubs may be multiple instances of the same identity hub, only a full description of the first identity hub <NUM> will be provided as this description may also apply to the identity hubs <NUM> through <NUM>. As illustrated, identity hub <NUM> may include data storage <NUM>. The data storage <NUM> may be used to store any type of data that is associated with the DID owner <NUM>. In one embodiment the data may be a collection <NUM> of a specific type of data corresponding to a specific protocol. For example, the collection <NUM> may be medical records data that corresponds to a specific protocol for medical data. The collection <NUM> may include any other type of data, such as attestations made by or about the DID owner <NUM>.

In one embodiment, the stored data may have different authentication and privacy settings <NUM> associated with the stored data. For example, a first subset of the data may have a setting <NUM> that allows the data to be publicly exposed, but that does not include any authentication to the DID owner <NUM>. This type of data may be for relatively unimportant data such as color schemes and the like. A second subset of the data may have a setting <NUM> that allows the data to be publicly exposed and that includes authentication to the DID owner <NUM>. A third subset of the data may have a setting <NUM> that encrypts the subset of data with the private key <NUM> and public key <NUM> pair (or some other key pair) associated with the DID owner <NUM>. This type of data will require a party to have access to the public key <NUM> (or to some other associated public key) in order to decrypt the data. This process may also include authentication to the DID owner <NUM>. A fourth subset of the data may have a setting <NUM> that restricts this data to a subset of third parties. This may require that public keys associated with the subset of third parties be used to decrypt the data. For example, the DID owner <NUM> may cause the setting <NUM> to specify that only public keys associated with friends of the DID owner <NUM> may decrypt this data. With respect to data stored by the storage module <NUM>, these settings <NUM> may be at least partially composed by the storage module <NUM> of <FIG>.

In some embodiments, the identity hub <NUM> may have a permissions module <NUM> that allows the DID owner <NUM> to set specific authorization or permissions for third parties such as third parties <NUM> and <NUM> to access the identity hub. For example, the DID owner <NUM> may provide access permission to his or her spouse to all the data <NUM>. Alternatively, the DID owner <NUM> may allow access to his or her doctor for any medical records. It will be appreciated that the DID owner <NUM> may give permission to any number of third parties to access a subset of the data <NUM>. This will be explained in more detail to follow. With respect to data stored by the storage module <NUM>, these access permissions <NUM> may be at least partially composed by the storage module <NUM> of <FIG>.

The identity hub <NUM> may also have a messaging module <NUM>. In operation, the messaging module allows the identity hub to receive messages such as requests from parties such as third parties <NUM> and <NUM> to access the data and services of the identity hub. In addition, the messaging module <NUM> allows the identity hub <NUM> to respond to the messages from the third parties and to also communicate with a DID resolver <NUM>. This will be explained in more detail to follow. The ellipsis <NUM> represents that the identity hub <NUM> may have additional services as circumstances warrant.

In one embodiment, the DID owner <NUM> may wish to authenticate a new device <NUM> with the identity hub <NUM> that is already associated with the DID <NUM> in the manner previously described. Accordingly, the DID owner <NUM> may utilize the DID management module <NUM> associated with the new user device <NUM> to send a message to the identity hub <NUM> asserting that the new user device is associated with the DID <NUM> of the DID owner <NUM>.

However, the identity hub <NUM> may not initially recognize the new device as being owned by the DID owner <NUM>. Accordingly, the identity hub <NUM> may use the messaging module <NUM> to contact the DID resolver <NUM>. The message sent to the DID resolver <NUM> may include the DID <NUM>.

The DID resolver <NUM> may be a service, application, or module that is configured in operation to search the distributed ledger <NUM> for DID documents associated with DIDs. Accordingly, in the embodiment the DID resolver <NUM> may search the distributed ledger <NUM> using the DID <NUM>, which may result in the DID resolver <NUM> finding the DID document <NUM>. The DID document <NUM> may then be provided to the identity hub <NUM>.

As discussed previously, the DID document <NUM> may include a public key <NUM> or <NUM> that is associated with the new user device <NUM>. To verify that the new user device is owned by the DID owner <NUM>, the identity hub <NUM> may provide a cryptographic challenge to the new user device <NUM> using the messaging module <NUM>. This cryptographic challenge will be structured such that only a device having access to the private key <NUM> will be able to successfully answer the challenge.

In this embodiment, since the new user device is owned by DID owner <NUM> and thus has access to the private key <NUM>, the challenge may be successfully answered. The identity hub <NUM> may then record in the permissions <NUM> that the new user device <NUM> is able to access the data and services of the identity hub <NUM> and also the rest of the identity hubs <NUM>.

It will be noted that this process of authenticating the new user device <NUM> was performed without the need for the DID owner <NUM> to provide any username, password or the like to the provider of the identity hub <NUM> (i.e., the first cloud storage provider) before the identity hub <NUM> could be accessed. Rather, the access was determined in a decentralized manner based on the DID <NUM>, the DID document <NUM>, and the associated public and private keys. Since these were at all times in the control of the DID owner <NUM>, the provider of the identity hub <NUM> was not involved and thus has no knowledge of the transaction or of any personal information of the DID owner <NUM>.

In another example embodiment, the DID owner <NUM> may provide the DID <NUM> to the third-party entity <NUM> so that the third party may access data or services stored on the identity hub <NUM>. For example, the DID owner <NUM> may be a human who is at a scientific conference who desires to allow the third party <NUM>, who is also a human, access to his or her research data. Accordingly, the DID owner <NUM> may provide the DID <NUM> to the third party <NUM>.

Once the third party <NUM> has access to the DID <NUM>, he or she may access the DID resolver <NUM> to access the DID document <NUM>. As previously discussed, the DID document <NUM> may include an end point <NUM> that is an address or pointer to services associated with the decentralized identity.

Completing the research data example, the third party <NUM> may send a message to the messaging module <NUM> asking for permission to access the research data. The messaging module <NUM> may then send a message to the DID owner <NUM> asking if the third party <NUM> should be given access to the research data. Because the DID owner desires to provide access to this data, the DID owner <NUM> may allow permission to the third party <NUM> and this permission may be recorded in the permissions <NUM>.

The messaging module <NUM> may then message the third party <NUM> informing the third party that he or she is able to access the research data. The identity hub <NUM> and the third party <NUM> may then directly communicate so that the third party may access the data. It will be noted that in many cases, it will actually be an identity hub associated with the third party <NUM> that communicates with the identity hub <NUM>. However, it may be a device of the third party <NUM> that does the communication.

Advantageously, the above described process allows the identity hub <NUM> and the third party <NUM> to communicate and to share the data without the need for the third party to access the identity hub <NUM> in the conventional manner. Rather, the communication is provisioned in the decentralized manner using the DID <NUM> and the DID document <NUM>. This advantageously allows the DID owner to be in full control of the process.

As shown in <FIG>, the third party <NUM> may also request permission for access to the identity hub <NUM> using the DID <NUM> and the DID document <NUM>. Accordingly, the embodiments disclosed herein allow access to any number of third parties to the identity hubs <NUM>.

For the processes and methods disclosed herein, the operations performed in the processes and methods may be implemented in differing order. Furthermore, the outlined operations are only provided as examples, an some of the operations may be optional, combined into fewer steps and operations, supplemented with further operations, or expanded into additional operations without detracting from the essence of the disclosed embodiments.

Claim 1:
A method for generating a cryptographic key (<NUM>, <NUM>) by connecting with one of multiple possible entropy generation components (<NUM>) that may provide input entropy to be used for generating the cryptographic key, the method comprising:
causing a key generation component (<NUM>) to provide an interface (<NUM>) that exposes (<NUM>) a set of one or more required cryptographic key input entropy characteristics (<NUM>) for input entropy to be used to generate a cryptographic key, the key input entropy characteristics comprising a specified minimum or maximum time for generating the entropy;
causing an entropy generation selection component (<NUM>) to interpret the one or more characteristics of input entropy that is to be used by the key generation component;
causing the entropy generation selection component to select an appropriate entropy generation component of the multiple entropy generation components that is capable of providing input entropy having the required characteristics;
connecting (<NUM>) the selected entropy generation component to the interface;
receiving (<NUM>; <NUM>), via the interface, input entropy from the entropy generation component, the input entropy satisfying the set of one of more cryptographic key input entropy characteristics exposed by the interface; and
causing the key generation component to generate (<NUM>) a cryptographic key using the received input entropy.