Patent Publication Number: US-9900309-B2

Title: Methods for using digital seals for non-repudiation of attestations

Description:
CROSS REFERENCES TO RELATED APPLICATIONS 
     This application is a divisional application of U.S. Utility patent application Ser. No. 14/503,797, filed Oct. 10, 2014, entitled as “Electronic Identity and Credentialing System”, and claims the benefit of U.S. Provisional Patent Application No. 61/885,251, filed Oct. 1, 2013, entitled as “Electronic Identity and Credentialing System”, which is incorporated herein by reference in its entirety. 
    
    
     FIELD 
     The present invention relates to the field of identity provisioning and usage over information networks. The scope traverse&#39;s identity, credentials, credentialing, also known as identity provisioning, identity assurance, security, privacy, confidentiality, authentication, encryption, and identity management. To assist interpreting the field and scope, a glossary of terms relating to this field is provided as well figures and a list of reference numerals. 
     To ensure personal privacy while provisioning reliable identities for citizens and consumers, the specification, handling and deployment of personal identities needs to be modernized. To date, the provisioning of identities and credentials have been primarily the prevue of web service providers. For identity and credentialing to scale up and become significantly more trusted than existing schemes, individual persons must become increasingly engaged in vetting the identities of other persons and the issuing of credentials to them. Credential owners must be able to reliably and safely control their identities, and unauthorized persons should not be able to fraudulently use the identities of others. 
     In the real world, physical credentials such as driver&#39;s licenses and passports attesting to the identity of the holder are primarily issued by governments, banks, employers, and other types of organizations. Notably, the agents and HR departments of such organizations perform most of the necessary vetting and proofing procedures prior to credential issuance. Physical credentials are rarely issued by individuals to other individuals. However, notaries can issue certified true copies of documents to individuals, and professional engineers, doctors and other professionals can certify true copies of personal identifying information (e.g. passport applications). 
     Over the Internet, prior art Public Key Infrastructure (PKI), a hierarchical trust model, is the predominant identity provisioning scheme by which identities, in the form of digital certificates, are distributed electronically to enterprises—rarely to individuals. Another technology, Pretty Good Privacy (PGP), a web-of-trust model focused on the identity needs of individuals, employs digital certificates to enable secure communications among personal computers. PGP has enjoyed limited market penetration and was not specified to integrate with PKI. The escalating problems of electronic identity theft and fraud have not been solved by either of these technologies. The present invention significantly improves upon prior art PKI and PGP technologies. 
     E-fraud is perpetrated over information networks, such as the Internet and cellular networks, by way of identity theft, identity abuse, electronic stalking, spamming, advertising abuse, obfuscation, phishing and deception. Service providers and enterprise systems have been rapidly losing ground in their battle against web-based identity abuse and e-fraud, mainly because today&#39;s identity providers and technologies are not able to deliver identities to individuals that can only be readily used by the identity owner. As the Internet continues to grow rapidly in both size and complexity, the providers of web services and end-user computing devices are increasingly hard-pressed to keep up with the escalating breaches, compromised identities, and fraudulent activities—all widely reported across the web. 
     The essential difficulty in the field of electronic identity is that communicating parties are often unknown to each other, yet they need to conduct transactions with each other as if they were meeting face-to-face. In most circumstances today, a web user as well as a web server cannot be really sure who they are communicating with. Users may wonder if the web site they are visiting is bogus; if their service provider has been properly protecting their accounts and credit cards; if a virus or Trojan software is collecting their private information; or if a blog post is from an imposter or a stalker. The user is obliged to rely on legacy technologies that may be defective, poorly configured, and poorly administered. 
     For example, account/password authentication schemes are known to be vulnerable to compromise enabling user masquerade (spoofing), denial-of-service, and other abuses. The problems of users and servers managing multiple passwords, re-used passwords, weak passwords, and password resets are widely known. Furthermore, successful access into a system with account/password login only proves that the holder of the account has knowledge of the password; it does not validate the identity of the person knowing the password. 
     For remote parties to collaborate safely over the web, they need to be able to reliably authenticate each other over a communications channel that cannot be sniffed (read) or tampered with. In other words, they need to be strongly bound to each other across every hop from origination to destination (“end-to-end”). 
     Single sign-on (SSO) and federated identity frameworks and technologies have addressed some of the challenges of enrolling users, specifying accounts and permissions, containing password proliferation, and managing user passwords. However, the structures for specifying user identities are fragmented, the methods for defining and issuing them are ad hoc, and effective credential interoperability does not exist at this time. 
     A wide variety of biometric technologies have emerged over the years and have been integrated into personal computers, smart phones, smart cards and various types of security tokens. Digital certificates have also been deployed on smart card technologies and USB thumb drives. Notably, FIPS PUB 201-2 for Personal Identity Verification (PIV) specifies a smart-card based identity card and related systems deployed by the U.S. Federal government. 
     The approach taken herein leverages selected aspects of prior art identity technologies and emulates identity issuance and usage in the physical world. Such an approach can be expected to facilitate adoption. Consider a driver&#39;s license. Such a credential bears the name and selected attributes of the owner, a photograph, the owner&#39;s signature, and certain endorsements and restrictions. After “proofing” the applicant against provided identifying information, the agent issues the license to the applicant. When used, the license attests to the owner&#39;s identity which the issuer cannot easily repudiate. If the license is borrowed or stolen and subsequently presented by someone other than the owner, the photograph and signature can be used by others to detect fraudulent use. 
     The present invention follows a similar process employing “personal identity devices”. A wide range of electronic credentials can be specified therein such that they are information-wise equivalent to civil and consumer credentials such as driver&#39;s licenses, bank cards, employee IDs, and even business cards. Users, some of whom may be agents of identity provisioning services, are able to collaborate and securely exchange electronic identities that have been proofed and attested to by other users (issuers). The issuer&#39;s identity is cryptographically bound to the owner&#39;s electronic identity preventing the issuer from repudiating their attestation thereby elevating assurances for 3 rd  parties. The personal identity device also leverages user authentication data to bind the user to their electronic identities. These features combine to elevate privacy, prevent identity tampering, and prevent others from using electronic credentials to masquerade as the identity owner. 
     The present invention specifies an electronic identity and credentialing system that combines and adapts prior art to achieve the following distinct features and capabilities:
         Mimics identities and credentialing as practiced in the physical world to facilitate adoption;   Leverages growing population of consumers owning personal devices to create personal identity devices;   Enables personal identity device owners to specify, control, proof, attest to, issue, and use their identities for assured collaboration among themselves and secure web access;   Persistently binds owners to their identity devices, and hence their identities (e-credentials) and associated secrets (e.g. private keys and biometric minutia), by controlling local user authentication data;   Combines and adapts prior art, preventing 3 rd  party masquerade, such that only a personal identity device owner can employ one of their identities (e-credentials) to execute privileged operations that ensure:   Messages, digitally signed under the owner&#39;s e-credential, were originated by that same owner;   Only the owner can read messages encrypted employing an e-credential of the owner;   Artifacts digitally sealed under the owner&#39;s e-credential must have been affixed by the owner;   Another user, having received a copy of an owner&#39;s e-credential, can challenge a user claiming to be that owner, thereby obtaining assurances that the provided e-credential actually represents the claimed owner;   Owners of personal identity devices can use their e-credentials in concert with the e-credentials of other owners to establish persistent, mutually trusted, secure sessions executing the above privileged operations;   An e-credential issuer can proof the personal identifying information of an e-credential requester, issuing a digitally sealed e-credential to the requester that attests to the requester&#39;s identity.   Users with personal identity devices and e-credentials that have been digitally sealed can thereby establish secure channels among themselves wherein they have positive assurances as to the other party&#39;s identity.       

     U.S. Pat. No. 7,660,988 by Camechael discloses an electronic notary process (“e-notary”) wherein a notary and client can share a workstation, log onto a remote system, and notarize a submitted document by means of a cryptographic scheme that creates a record of the notarization event in the system&#39;s online repository. The present invention makes no claims related to using a centralized database to perform electronic notarization, instead specifying a distributed approach whereby users can attest to (e.g. notarize) each other&#39;s electronic documents and credentials using personally help identity devices. 
     WO2005020542 by Salim Aissi et al. discloses a method that binds a public key to specific hardware with an embedded private key to verify the identity and integrity of the trusted computing device. In contrast, the present invention, by means of a personal identity device held by the device owner, binds personal identities of the owner, including public and private keys associated with each identity, to the owner. 
     EP 2460307 by Jeffery B. Williams et al. discloses a system and methods for strong remote identity proofing, obtaining biographical information from the individual, and using this information to search public data repositories. No claims related to obtaining biographical information to search data depositories for identities are made herein. 
     EP 1470534 by Vipin Samar et al. discloses a method and apparatus for authenticating an individual&#39;s identity by validating a credential and corresponding public key, and comparing biometric data with sample data. No claims are made herein specifying any given biometric scheme or biometric data. Rather, the present invention encapsulates authentication data utilized by biometric mechanisms pre-installed on the personal identity device of the user. 
     EP 1130491 by Corella et al. discloses a method for structuring a digital certificate comprised of multiple authorization hashes that a relying party can use to access relevant authorization information. The present invention does not claim to create, filter, mask or hash authorization data that relying parties can use to make authorization decisions. In contrast, the present invention creates identities that can be provided to other parties to make authorization decisions outside the context and scope of the present invention. 
     U.S. Pat. No. 8,127,228 by Cheng et al. discloses a method and a system for electronic document management based on human memory wherein a digital seal is a personalized association mnemonic applied to a document comprised of, for example, icons and text. This prior art does not appear to apply cryptography, while the present invention uses cryptography, creating digital seals that can be visually rendered and cannot be repudiated by the e-credential owner; 
     U.S. Pat. No. 7,310,734 by Boate et al. discloses an improved network security system, methods and a personal identifier device, used to control network access and real time authentication of a user&#39;s identity and presence at a particular network access point. Biometric verification and cryptography is provided on-board the portable personal digital identifier device to provide authenticated digital signatures which are used for establishing secure access to data stored on a network and for performing secure transactions over a network. Biometric authentication is used to verify user presence, and biometric data is used to create digital signatures, subsequently used for secure access. In contrast, the present invention does not perform biometric verification or matching, or use biometric data to create digital signatures, instead holding authentication data, including biometric minutia, within an identity engine, and relying on an authentication control interfaced to a pre-existing biometric module (assumed to be present), to invoke user authentication and thereby establish user persistence. 
     U.S. Pat. No. 8,019,691 by Dominguez et al. discloses methods and systems for authenticating the identity and validating the profile data of an individual (presenter) who presents him or herself to another party (acceptor) performed online, possibly querying a trusted party for profile data. Although the present invention leverages an equivalent procedure called “identity proofing”, the administrative (human) details of such a procedure are not specified and are incidental to the present claims. The present invention does, however, specify artifacts and methods needed to enable mutually trusted sessions between requesters and issuers when conducting identity proofing, a feature that is not addressed by this prior art. 
     U.S. Pat. No. 6,401,206 by Khan et al. discloses methods and computer programs for creating a portable digital identity of the individual that may include personal information, data representing the person&#39;s handwritten signature, one or more passwords, seals, fingerprints, biometric information, and answers to questions that are composed by the user. The digital identity can be used to bind a verifiable electronic impression with an electronic document using electronic watermarks so that any modification in the document or the electronic impression bound to the document can be detected. The digital identity of a user can be created once and stored after encryption for protection. This digital identity can then be used by the signer to bind a unique instance of an impression of the digital identity to any document. Document and digital identity verification including verifying a cryptographic digital signature that establishes the integrity of the document, enables non-repudiation of origin to the extent that it was signed by the user&#39;s private key. 
     An e-credential does not contain handwritten signature, passwords, biometric data (e.g. fingerprint minutia), answers to user questions, or other such sensitive information because an e-credential is normally disclosed to collaborating parties to support user collaboration. Also, the present invention does not attempt to generate public-private key pairs from personal identifying information to apply a cryptographic signature to documents, choosing instead to create three (3) public-private key pairs, embedding the public keys in the user&#39;s e-credential, and retaining the private keys in protected memory store (possibly removable) of the personal identity device which is strongly bound to the user. The present invention uses two of these public-private keys to support secure remote collaboration, which the prior art does not, reserving one of the key pairs for digital sealing and verifying of electronic documents. This prior art discloses that it ensures non-repudiation to the extent that the cryptographic signature was signed by the user&#39;s private key. In contrast, the present invention ensures that the private key (the “embossing” key) used to digitally seal an electronic document, is persistently in the custody of the user, thereby elevating non-repudiation strength over this prior art. 
     Password and PIN-based authentication schemes, despite their acknowledged weaknesses, continue to be used because of their ease-of-use and ease-of-implementation properties. Password-based remote password authentication schemes, including those using Personal Identity Numbers (PINs), have been long-demonstrated to be vulnerable to user masquerade. Local password and PIN-based schemes are less vulnerable as such user secrets are not exposed over intervening networks. However, the all too common practice has been for users to employ the same passwords and PINs for both local and remote access. 
     Employing a number of fairly straight-forward exploits (e.g. sniffing and social engineering) and readily available software tools for password-cracking, a malicious attacker can defeat traditional PIN and password-based authentication, using the acquired private information (account numbers and identifiers) and user secrets (the PINs and passwords themselves) to fraudulently tamper with online accounts. Risks can be reduced by introducing guidelines for creating stronger passwords, automated procedures for creating non-guessable passwords, augmenting these schemes with non-guessable security questions, incorporating behavioral analysis, detection, automated blocking tools, implementing safer account reset procedures, and elevating user awareness of social engineering attacks and scams providing avoidance advice. Routine reuse of the same and similar passwords and PINs should be prohibited or at least strongly discouraged. 
     Pioneered by Liberty Alliance and other players in the late 1990s and early 2000s, single-sign-on (SSO) solutions federate identity provisioning and access enabling users to be authenticated in a small number of places, or possibly at a single centralized location. Such approaches can significantly reduce the number of PINs and passwords required, however, they require users to be authenticated online at points of consolidation and centralization that must in turn be networked to achieve deployment on a wide-spread, potentially global scale. The consolidation points present attractive targets for various cyber-attacks. 
     The present invention promotes a distributed approach for identity acquisition and provisioning that promises to be highly scalable and avoids the above-cited weaknesses of password and PIN-based remote access schemes. 
     Fingerprint, facial, and iris recognition schemes are commercially viable for deployment on user platforms (e.g. PCs and smart phones). Ma reports the relative accuracy of available biometrics in terms of false positive rates with facial recognition at 43%, fingerprint at 30%, signature at 28%, voice at 20%, and iris recognition at only 0.47%. This helps explain the growing interest in iris biometrics. 
     User preferences for biometric schemes, matching accuracy, matching performance, human risks factors, and compatibility with the individual circumstances can vary widely, implying that solutions should offer users a range of biometric options for remote user authentication. 
     Meanwhile, emerging biometric signatures leveraging the body&#39;s venous, nervous and DNA systems are being studied by research institutions and can be expected to emerge over time. This observation suggests that biometric-based identity solutions should be extensible, accommodating add-on biometric technologies in a modular fashion as they emerge. 
     As users become better informed about the privacy risks posed by global networks, users are also becoming increasingly skeptical about systems that maintain biometric minutia and templates for biometric matching at consolidated and centralized locations. This suggests that biometric authentication schemes should de-centralize biometric capture and matching, putting such sensitive operations in the custody and control of users, that is, within their personal devices. 
     The inventive subject matter described herein advocates an authentication approach that consolidates biometric minutia (i.e. authentication data), regardless of the type of biometric, into a personal device controlled by the user which enables incorporating a range of biometric options that can be integrated in a modular fashion. 
     Multi-factor authentication technologies have been emerging and being increasingly advocated. Multiple authentication factors can be applied jointly to reduce the probability of failed authentication due to the compromise or fallibility of any given factor or factors. MFA typically addresses “What the user knows” (PIN, password, responses to questions), “What the user has or holds” (smart card, smart phone, FOB), and “What the user is” (iris, fingerprint, facial and other biometrics). Geo-location and behavioral authentication schemes are also factors that can be incorporated. 
     Extant solutions include 2-factor authentication schemes for banking that use a PIN and chip card (a smart card), hardware tokens that generate one-time-passwords (OTPs) for remote terminal logon, and smart phone solutions that integrate the text messaging channel of the phone to distribute OTPs to users when using a personal computer. 
     The inventive material herein accommodates MFA combining device custody, with local PIN/password authentication, and biometric options. 
     The prior art discloses public key infrastructure (PKI) and digital certificates an identity technology, introduced to automate the deployment of public-private encryption key pairs for secure communications, message transmission, and document safe-keeping. Digital certificates, conforming to the X.509 standard, include a public encryption key that is paired with a private key stored outside the context of the digital certificate. Tests can be performed to verify that a remote party holds the private key of a public key without having knowledge of the private key. PKI implements a hierarchical trust model wherein certificate authorities successively distribute digital certificates to dependent certificate authorities, Internet servers, and end-user devices. Digital certificates and their corresponding private keys are distributed by certificate authorities to other certificate authorities, to servers, and to end-user devices. Certificate authorities have the option of employing qualified human agents for 3 rd  party identity proofing and verification. 
     The present invention improves upon the above features, overcoming the following deficiencies of PKI:
         (a) Using qualified independent certificate authorities, effective for verifying and tracking the identity of service providers, does not scale for human beings who outnumber servers by orders of magnitude;   (b) Because public-private key pairs are generated by certificate authorities and subsequently distributed electronically, such key pairs could be vulnerable to compromise during distribution;   (c) Because X.509 digital certificates only specify the certificate holder by a common name or identifier, identities of persons cannot be specified comprehensively for commercial and other such applications;   (d) Digital certificates do not readily bind with other personal identifying information of an owner such as digital photographs or personal identifying information (e.g. passport, driver&#39;s license, certifications);   (e) Although digital certificates enable relying parties to verify that the digital certificate owner has the private key that matches the public key of a digital certificate, PKI does not incorporate personal identifying information that reliably distinguishes the certificate owner from other users;   (f) PKI does not provide assurances that the private key is strongly bound to the certificate owner;   (g) PKI does not incorporate identity proofing and binding capabilities that provide objective evidence to relying parties that an independent party has attested to the identity of the digital certificate holder;   (h) Because X.509 certificates are associated with a single public-private key pair, typically multi-purposed (e.g. used for digital signing, encryption, email, FTP, etc.), the risks of encryption key compromise are elevated over other approaches.       

     Finney et al. discloses Pretty Good Privacy (PGP) which was introduced to automate the deployment of public-private key pairs among persons (peer-to-peer) to secure communication channels, transmitted messages, and documents among PGP users. In contrast to PKI, PGP implements a web of trust model wherein individuals issue digital certificates to each other. An end-user, having installed the PGP software on their personal computer, creates an X.509 digital certificate containing a single public key with matching private key stored on the user&#39;s computer. PGP enables an informal process whereby a first user can send such a certificate to a second PGP user who digitally signs and returns the certificate to the first user. By retaining the single private key of a digital certificate within the owner&#39;s computing device, PGP reduces the risk of exposing and compromising this private key. This approach for creating and sharing digital certificates can be replicated among users with PGP software on their computing devices. PGP users can present one or more signed digital certificates to relying parties (users), elevating identity assurances when presented to other parties. 
     The present invention improves upon the above features, overcoming the following deficiencies of PGP:
         (a) Because X.509 digital certificates only specify the certificate holder by a common name or identifier, identities of persons cannot be specified comprehensively for commercial and other such applications;   (b) Digital certificates do not readily bind with other personal identifying information of an owner such as digital photographs or personal identifying information (e.g. passport, driver&#39;s license, certifications);   (c) Although digital certificates enable relying parties to verify that the digital certificate owner has the private key that matches the public key of a digital certificate, PGP does not incorporate personal identifying information that reliably distinguishes the certificate owner from other users;   (d) PGP does not provide assurances that the private key is strongly bound to the certificate owner;   (e) PGP does not incorporate a formal identity proofing process whereby relying parties are provided objective evidence of a user&#39;s identity;   (f) Because X.509 certificates are associated with a single public-private key pair, typically multi-purposed (e.g. used for digital signing, encryption, email, FTP, etc.), the risks of encryption key compromise are elevated over other approaches.       

     Glossary of Relevant Terms 
     Identity: The present invention addresses only the identity of persons [i.e. human beings, individuals, users]. The identity of a person is comprised of selected characterizing attributes of the person that are attested to by one or more independent persons. The attributes of a person may include a combination of full legal name, commonly used names, pen names [pseudonyms], selected identifier(s), and various physical and non-physical attributes of the person. In the limit, the identity of a person is aggregated characterization of that person that distinguishes the person from all of other persons. In the future, DNA signatures could very well be used as identity attributes. 
     Identifiers: Identifiers are often confused with identity. An identifier, such as a social security number, a passport number, an email address or an employee number is an attribute of a person assigned by an agent of the government, a service provider, or an employer, and thereby contributes to a person&#39;s identity, but by itself does not constitute the person&#39;s identity. 
     Credential: A credential is a document held by a person that captures selected personal identifying information of the individual. A credential thereby partially represents the identity of the person. A person without any credentials or identifying documents has no documented identity and must rely on the attestations of other persons. An adult holding only a birth certificate, and no other credentials, would find it very difficult to conduct most day-to-day transactions. The attributes of a person are generally captured and specified by several credentials. The conjunction of all credentials held by a given person represents the total documented identity of the person. It is impractical and ill-advised to capture all of the attributes of a person in a single credential since disclosure or loss of such a comprehensive credential would compromise the entire identity of the person. 
     Credentialing: Credentialing is a process by which credentials, whether physical or electronic, are issued to individual persons. A person presents a credential to other persons when asserting their identity or presenting selected attributes of a credential. Credentialing is also known as identity provisioning. 
     Physical Credentials: Passports and driver&#39;s licenses are the most widely accepted physical credentials used to verify a given person&#39;s identity. A driver&#39;s license is an example of a physical card that specifies the holder&#39;s name, allocated license number, address, birthday, issue date, expiry date, and photograph. Issued by a state Departments of Motor Vehicles (DMV), such a physical credential also displays the issuer&#39;s jurisdiction plus watermarks and other technologies designed to detect and prevent credential tampering. Table 1 categorizes physical credentials in common use. 
     
       
         
           
               
             
               
                 TABLE 1 
               
               
                   
               
               
                 Physical Credentials and Identifying Information (categorized) 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
            
               
                 Life Event Credentials 
                 Civil Credentials 
                 Other Identifying Info 
               
               
                   
               
               
                 Birth 
                 Social Security Card 
                 Utility Bill 
               
               
                 Baptism 
                 Global Entry/Nexus 
                 Property Record 
               
               
                 Marriage 
                 Citizenship 
                 Background Report 
               
               
                 Divorce 
                 Passport 
                 Credit Report 
               
               
                 Death 
                 Immigration Status 
                 Resume 
               
               
                   
                 Voter Registration 
                 Loan 
               
               
                   
                 Work Authorization 
                 Rental Agreement 
               
               
                   
                 Driver&#39;s License 
                 Mortgage 
               
               
                   
                   
                 Photo 
               
               
                   
                   
                 Tax Return 
               
               
                   
                   
                 Payroll Record 
               
               
                   
               
               
                 Educational 
               
               
                 Credentials 
                 Professional Credentials 
                 Financial Credentials 
               
               
                   
               
               
                 Diplomas 
                 Notary 
                 Debit Card 
               
               
                 Diplomas 
                 Lawyer 
                 Credit Card 
               
               
                 Degrees 
                 Engineer 
                 Merchant Charge 
               
               
                 Transcripts 
                 Physician 
                 Card 
               
               
                 Certifications 
                 Dentist 
               
               
                   
                 Architect 
               
               
                   
                 Accountant 
               
               
                   
                 Teacher/Professor 
               
               
                   
                 Certified Professional 
               
               
                   
               
               
                   
                 Other Credentials 
               
               
                   
               
               
                   
                 Business Card 
               
               
                   
                 Employee ID 
               
               
                   
                 Business Membership 
               
               
                   
                 Association Membership 
               
               
                   
                 Social Membership 
               
               
                   
                 Loyalty Card 
               
               
                   
               
            
           
         
       
     
     Anti-fraud and Anti-copying: Ancient measures for protecting against fraud and tampering can be traced back to the use of wax seals and steganography. Wax seals were applied by monarchs to protect sensitive messages and official decrees. Equivalent techniques are still used by professional engineers, architects and notaries to seal drawings, physical credentials and other documents. The notary&#39;s process of applying seals to documents by means of an embossing device has been adapted to suit the needs of this invention. 
     Certified True Copies: To create a certified true copy of a physical credential such as a driver&#39;s license, a notary “proofs” a photocopy asserted to be a true copy of the driver&#39;s license by comparing the photocopy to the original driver&#39;s license, and verifying that they both match the person requesting the true copy. If satisfied, the notary applies a “true copy” declaration to the photocopy, and then uses an embosser to apply the notary&#39;s seal to the document. The applied seal identifies the notary, prevents others from tampering with the certified true copy including the “true copy” declaration, and thereby binds the notary&#39;s identity to the identity of the person specified in the copy. In prescribed circumstances, the certified true copy of an original driver&#39;s license can be used in lieu of the original for identification purposes, that is, the true copy is, in effect, a bona fide credential. Similarly, certified true copy translations (e.g. Spanish to English), and certified true copy photographs, can be proofed and sealed by a notary or a certified profession, for example, to support a person&#39;s application for a passport. 
     Physical Credentialing: Physical credentials have been generally issued by organizations, including governments, corporations, and financial institutions possessing the infrastructures and funding to issue fraud-resistant physical credentials. Smaller organizations including clubs, non-profits, affiliates, loyalty groups, and societies also issue physical credentials, albeit in simpler forms. In the final analysis, physical credential processing, including proofing and issuance, is performed by agents (individuals) who have been assigned to follow prescribed procedures of an identity provisioning institution. Credential proofing and issuing is, possibly, the most labor-intensive aspect of traditional physical credentialing systems. 
     Electronic Credentials: Electronic credentials, in the context of this inventive subject matter, are the digital equivalents of physical credentials. Electronic credentials are the electronic equivalents of passports, driver&#39;s licenses, banking cards, business cards, and all other such physical credentials (see Table 1), capturing and storing the names, identifiers, attributes, and photographs of individuals in software and electronic devices. Plastic credit and debit cards that capture the holder&#39;s name, an identifier, an expiry date, and possibly a photograph of the person within a magnetic strip or chip in the card (smart cards) are also are examples of electronic credentials. Software-based identities, “virtual identity cards”, and electronic wallets” deployed on personal computers and in the “cloud” are also available. Relevant credentialing terms include: 
     Electronic Credentialing: Electronic credentialing is a process by which a credential issuer, an individual or an organization, collaborates with users to request, proof, and provision electronic credentials (e-credentials) to individuals. The requester submits a request for a new e-credential to the issuer; the issuer proofs the provided documents; and, when satisfied, issues an e-credential to the requester. 
     In-Person and Online E-Credentialing: Depending on the associated risks and the required level of identity and credential assurances, credentialing may involve a blend of in-person proofing and online proofing. In-person encounters will be appropriate to support large-value high-risk transaction flows. However, in-person encounters can be labor-intensive, less convenient, and less timely. Online proofing can be accomplished using audio and teleconferencing tools once a mutually trusted communications channel is established between the parties. The exposure risk of online identity proofing can be mitigated deploying multi-factor authentication between the user the system and using out-of-band techniques to exchange shared secrets. 
     Electronic Credential Issuing Modes: An e-credential is issued by at least one person, possibly even the credential holder themselves (a “self-issued” credential); by one or more independent issuers without relevant qualifications; by issuers who have personally known the requester for a given number of years; by issuers with ethical obligations levied by their professional oversight body; by issuers who occupy professions with specific relevant obligations to inspect and certify identifying documents with oversight; and by issuers with directly relevant qualifications and oversight to issue credentials of the type requested. 
     Assurances: For an electronic credentialing system to be effective it must be trusted to attest to identifying information, capture the information in the form of electronic credentials, and securely maintain and make credentials available for identity maintenance and verification throughout the useful lifetime of the credentials and the system itself. The levels of trust provided by such a system is dependent on the combination engineering tasks applied to achieve correctness, integrity, reliability, security, and quality of the system, its artifacts, and methods. 
     Identity Assurance: When communicating with a remotely located persons or services, collaborating parties need assurances as to the true identity of the parties. To support this requirement for persons [web services are beyond scope], the identifiers and attributes of a person (a subject), including legal, common, and pseudonyms, must be independently verified by independent persons known as issuers. The level of identity assurances achieved by the issuer depends on the extent the subject is known by the issuer (familiarity), and the relevant vetting and proofing competencies of the issuer. Relevant competencies for an issuer include proofing and vetting skills, objectivity, questioning skills, professional oversight by a governing body, and applicable code of conduct possibly sworn by oath—notary publics are exemplars. Identity assurances increase as the number of years that an issuer has personally known a subject, though not necessarily linearly. Identity assurance levels are also proportional to the above listed range of vetting and proofing competencies. Because objectivity and independence may conflict with familiarity, certain professionals, such as notaries and agents of credential issuing organizations, may be obliged to decline proofing and vetting a person who is too closely related to the issuer by way of family and employment. 
     Communications Assurance: The quality of communications when an issuer proofs the identity of a subject user has a significant impact on the efficacy of a credentialing system. Elevated levels of communications assurance can be achieved when the subject and issuer hold an in-person (face-to-face) encounter to exchange physical credentials and proof personally identifying documents. When a face-to-face encounter is not possible, identity proofing can be protected by establishing a mutually trusted communications channel between the parties using a shared secret exchanged out-of-band (over an alternate channel). For example, a shared pass-phrase could be exchanged over the telephone and a password-based scheme [ 2 ] generating a shared encryption key can be used to establish an encrypted session between the parties. 
     Credential Assurance: Credential assurance is directly dependent on identity assurance (familiarity and qualifications) and on the communication assurance (in-person encounters and trusted communication channels). However, credential assurance is separately proportional to the number of independent issuers proofing and attesting to a given credential. In other words, multiple proofing by independent issuers increases the level of credential assurance achieved. In addition, the relative binding strength between a credential issuer and a user receiving a credential elevates credential assurances. An issuer who is strongly bound to an issued credential will be challenged to repudiate having issued a credential to the subject and will therefore be proportionately motivated to thoroughly proof the identity of the subject. By the same token, relying parties, knowing that the issuer is strongly bound to credentials they issue, will be proportionately assured as to the relative assurance level of the subject&#39;s credential. 
     Authentication Assurance: Authentication assurances elevate the strength of bindings between a user and the local and remote services they use. Higher assurance levels for local authentication are achieved by employing multiple factors of authentication. Authentication factors include physical custody of the user&#39;s computing device plus knowledge-based, biometric-based and behavioral-based authentication schemes. Trustworthy remote authentication between a user&#39;s computing device and a remote server is generally accomplished by means of public-private keys derived from the user&#39;s locally stored credentials. 
     Software Assurance: The critical software components of an electronic credentialing system must be highly trusted and must also be protect by the operating system against malware, hacking and other attacks attempting to tamper-with, circumvent, or block the logic of the electronic credentialing system. Software assurance levels rise in proportion to the trustworthiness of the execution environment and the quality of the development effort (quality engineering, assurance, analysis, and testing). For example, a trusted execution environment capable of creating a “trust zone” within which the credentialing software executes will elevate software assurances. 
     Asymmetric key Encryption: Also known as public-private key encryption, algorithms that use two keys, a widely known public key and a private key known only to the owner. For example, the public key can be used to encrypt text that can only be decrypted by the paired private key. Alternately, the private key can be used to create a digital signature that can only be verified by the public key. RSA and Elliptical Curve (EC) are among the best known asymmetric key algorithms. 
     Authentication: User authentication is a security mechanism for binding a user to a controlled resource by validating the identity of the user, for example, through a logon process (e.g. account/PIN, and identifier/password pairs), and/or through a biometric matching process. Message authentication is a process for establishing the validity of a transmission, for example, through a cryptographically generated message authentication code attached to the message. Message origination authentication can be performed by using a private key of the originator to create a digital signature over the message which is verified by the recipient using the paired public key. 
     Biometric Minutia: In biometrics and forensic science, minutiae are enrolled features of a biometric, for example, a fingerprint scan, an iris scan, and a facial scan, that are used to algorithmically match future scans of an individual&#39;s biometric to authenticate the individual. 
     Cryptography/Encryption: A discipline of mathematics and computer science concerned with information security including algorithms that translate data and text into secret code strings known a cipher text. 
     Cryptographic: An adjective used to characterize encryption, digital signing, and digital sealing processes. 
     Crypto-logical Binding: Coined herein to characterize the binding between pairs of public-private keys wherein encryption by one key yields a result that can only be decrypted by the other key. 
     Digital Sealing: A cryptographic method defined herein that uses a private key of the issuer to bind the issuer&#39;s identity and a declaration of the issuer to a document or message such that the issuer cannot repudiate having applied the digital seal. The paired public key can be used to verify the digital seal. 
     Identity Binding: As used herein, binding an individual to their identity by way of custody of a device or devices (personal identity device and removable protected memory), user authentication to the user&#39;s device (control of authentication data), logical binding to the user&#39;s identity (identity engine encapsulating e-credentials of owner), and third party attestation by way of identity proofing and digital sealing of a declaration that cannot be repudiated. 
     Information Security: The protection of information to ensure confidentiality, integrity, and availability. 
     Issuer (payment card definition): An entity that issues payment cards or performs, facilitates, or supports issuing services including but not limited to issuing banks and issuing processors. 
     Hashing: a one-way mathematical function in which a non-secret algorithm takes any arbitrary length message as input and produces a fixed length output usually called a “message digest”. 
     Non-Repudiation: A state of affairs where a purported declaration by an individual cannot be successfully challenged, for example, when the authenticity of a signature applied to a contract is challenged. 
     PIN: Personal Identification Number. 
     Protected Memory Store: A memory that is, or can be, isolated from the primary working memory of a device such that this memory can only be accessed by a designated module (e.g. the “identity engine” herein). 
     Multifactor Authentication (MFA): Typically characterized by authentication factors based on (a) “what you know”, (b) “what you have” and (c) “what you are”, where factor (c) can be a biometric authentication factor or a behavioral authentication factor. Geo-location is also considered an authentication factor in certain contexts. 
     Out-Of-Band (OOB): A parallel channel to the primary information access channel. For example, when the primary session is a web session to a service provider, text messaging, voice, courier, and fax communications are considered out-of-band. 
     Personal Identifying Information (a.k.a. Personally Identifying Information): Information that can be utilized to identify or trace an individual&#39;s identity including but not limited to name, address, social security number, biometric data, date of birth, etc. 
     Sniffing: A technique that passively monitors messages over networks and channels for the purpose of collecting sensitive user information and intelligence including user accounts and passwords. 
     Symmetric Key Encryption: Algorithms that use the same encryption key to both encrypt and decrypt text and data (e.g. AES). 
     User Persistence: A condition that can be verified by performing a test that verifies that the same user is present (i.e. “is using”) at a remotely located device wherein the identity of the remote user need not be known. 
     SUMMARY 
     A novel system of electronic artifacts and methods for specifying, issuing, and using electronic identities is described. This system mimics physical credentialing systems, the aim being to offer an elevated assurance identity solution that will be readily adopted by citizens, consumers and enterprise users. The present invention overcomes the shortcomings of traditional password-based and digital certificate based identity systems. The present invention specifies a system for individual persons, as well as agents associated with identity services, to issue identities to other persons such that these identities can be employed by their owners to unambiguously identify themselves over information networks. 
     The present invention provides strong assurances to a relying party, namely to a user or to a service, that the collaborating remote user is strongly bound to their personal identity device and identities contained therein and thereby persistently present; that the identity presented by the collaborating remote user originated from that user, and no other user; that the identity presented by the remote user was attested to by at least one 3 rd  party user; that such 3 rd  party users cannot repudiate having attested to the identity provided to the remote user; that by means of the identity provided by the remote user, information sent to the remote party can only be read by that remote party, and no other parties; and that by means of the identity provided by the remote party, the relying party can verify that information received from the remote user, must have originated from that user, and no other user. 
     Unanticipated Discovery: By means of the identity of a user and a digital sealing method, a notarization-like procedure, the user can digitally seal a declaration to an electronic document, including an electronic identity, such that the user cannot repudiate having applied the digital seal to the declaration and the document. 
     The present invention specifies identity artifacts and methods that can be applied to adapt prior art personally held devices including smart phones, tablet PCs, laptops and personal computers for the purpose of identity acquisition, holding, issuance and usage. The sections below systematically explain how the new artifacts and methods of this innovation have been combined with prior art technologies to yield a new approach for electronic identity and credentialing. Context, practical pre-conditions, and relevant assumptions are also articulated. An ordinary person skilled in the art could not have discovered the inventive material through traditional design effort or happenstance. 
     Herein, an identity of a user is specified in the form of an electronic credential (e-credential) containing fragments of the e-credential owner&#39;s personal identifying information. 
     This innovation specifically avoids the weaknesses of remote password/PIN based authentication schemes wherein such user secrets are vulnerable to being discovered and “cracked”. It also offers a solution that avoids the risks of e-credentials being stolen from network repositories for fraudulent purposes. 
     The present invention overcomes these weaknesses and risks, creating an identity system where:
         (A) E-credentials of the owner can only be used by that owner to perform privileged operations, and   (B) An owner&#39;s e-credential cannot be employed by other users to masquerade as the e-credential owner.       

     By way of this invention, users control their e-credentials and secrets, acquire identities from one another, and use their e-credentials and associated secrets to enable secure information access and sharing with other users and information services:
         (i) Messages originated under the e-credential of an owner cannot be repudiated by that owner;   (ii) Messages received under the e-credential of the owner can only be read by that owner   (iii) Documents digitally sealed under the e-credential of the owner cannot be repudiated by that owner.       

     The present invention leverages identified prior art, combining selected features with new artifacts and methods. 
     This invention leverages prior art authentication schemes. It is assumed that the personal identity device of the user (the owner) has pre-installed authentication hardware and software mechanisms executing local PIN/password, biometric and/or other authentication schemes wherein authentication data (e.g. PIN/password hashes and finger print, iris, and facial recognition minutia) are retained within the personal identity device. Authentication factors, possibly combined (i.e. multi-factor authentication schemes), thereby persistently bind the user to their personal identity device and the e-credentials (identities) contained therein. 
     This innovation also leverages prior art public-private encryption key technology which enables a remote party to verify that an e-credential provided by an owner is in the custody (possession) of that owner. Public-private encryption technology associated with a selected e-credential is also used to perform digital signing, encryption and digital sealing operations that are bound to the e-credential owner by means of prior art public-private encryption technology. 
     The present invention introduces a novel method called “digital sealing” which adapts prior art digital signing technology. A digital seal applied under an e-credential of an owner, cryptographically binds a declaration of the owner to a selected document such that the owner cannot repudiate having applied the declaration to the document. 
     Specific limitations of legacy identity systems are overcome by:
         (a) Enabling the owner of a personal identity device to use that device to hold identities that are comprehensively specified in the form of electronic credentials (“e-credentials”);   (b) Leveraging pre-installed authentication mechanisms and related authentication data to persistently bind the device owner to e-credentials and secrets of the owner contained therein;   (c) Binding public-private keys to e-credentials of an owner to enable remote users to verify that an e-credential provided by the originating owner is in the owner&#39;s possession, and that subsequent digital signing, encryption, and digital sealing operations are bound to that owner;   (d) Specifying an identity proofing, attestation and digital sealing procedure whereby an e-credential issuer (a user) collaborating with an e-credential requester (another user), binds personal identifying information of the requester to an e-credential of the requester such that the issuer cannot repudiate having attested to the requester&#39;s identity specified by that e-credential.   (e) Enabling multiple users to proof, attest to, digitally seal, and issue a given e-credential thereby elevating identity assurances for relying parties who can inspect and verify at least one, and possibly all, digital seals applied to the e-credential of the owner.   (f) Enabling relying parties to inspect the e-credentials of each user having applied a digital seal, including the e-credentials of any, and possibly all, antecedent users having applied a digital seal, to achieve elevated assurances for high value transactions.       

     These capabilities combine to provide elevated assurances to collaborating parties that the remote party is persistently bound to any e-credential they provide, that the parties are thereby strongly bound to each other over persistent, secure communications channels, and that the provided e-credential unambiguously contains selected identifying information of the collaborating remote party. 
     The present invention assumes users have prior art smart phones, tablet PCs, laptops, and other such personal computing devices, that these devices have user interface(s), communications interfaces (e.g. Internet, cellular, NFC, Bluetooth), a native operating system, an authentication component, likely digital camera(s), possibly built-in hardware and/or software cryptographic libraries, and possibly a removable protected memory store such as an SD card, USB flash memory, or a smart card. The authentication component may support multiple user authentication mechanisms. It is assumed that the operating system is capable of preventing, detecting, and quarantining malware and remote hacking attempts thereby isolating the artifacts and methods of the present invention from active and passive tampering. Finally, it is assumed that the user&#39;s device and software may have pre-determined identifiers and that the artifacts and methods of this invention are pre-installed. 
     The key artifacts of the present invention include personal identity devices of users (owners), each device having an identity engine for holding and managing electronic identities and secrets of the device owner as well as the identities of other device users. The identity engine specifies electronic identities of the device owner by capturing selected identifying information of the user which the identity engine embeds into newly created “electronic credentials” (e-credentials) encapsulated by the identity engine. The user&#39;s identifying information is captured by means of user interface(s) including digital camera(s) if present. The camera(s) can be used, for example, to take self-photographs, and photographs of the other identifying information of the user (e.g. certificates, licenses, driver&#39;s license). The identity engine captures the e-credentials of others users by requesting them from collaborating users over information networks and/or by acquiring them from remote identity repositories. 
     Secrets of a device owner such as authentication data (e.g. PIN/password hashes, biometric templates, and behavioral criteria), and private encryption keys, are retained in a protected memory store such that the secrets can only be accessed and used by the identity engine and are not disclosed by the identity engine. When such a protected memory store is physically removable from the owner&#39;s device, and can be re-attached, it is called an “ignition key”. 
     Combining Distinguishing Features Yields Remarkable Capabilities 
     The distinguishing features of the present invention are combined to yield the following remarkable capabilities:
     (a) The identity engine of the owner&#39;s personal identity device controls a protected memory store containing the owner&#39;s authentication data. Once authenticated, the user is thereby persistently bound to the identity engine including contained e-credentials and three (3) public-private keys associated with each e-credential. The private keys are also maintained within the protected memory store. If the protected memory store is removable, the identity engine can be disabled by removing the memory restore.   (b) By way of (a), e-credentials maintained within the identity engine of an owner&#39;s device can be exchanged and used to establish persistent, secure sessions between collaborating users. Using their respective e-credentials and associated public-private key pairs, e-credential owners can exchange messages that have been digitally signed by the sender and encrypted for the recipient. Owners can also use their e-credentials and associated keys to digitally seal and inspect (verify) documents and messages. Although these mechanisms ensure that owners are strongly bound to their e-credentials, collaborating users cannot be certain that the identifying information embedded in the e-credential provided by the other party actually represents the identity of the other user.   (c) Having established a persistent, secure session by way of (b), one user (the issuer) can proof and attest to the identity of another user (the requester), digitally seal the requester&#39;s e-credential, issue the credential to the requester, and thereby provide the requester with an attested to e-credential that the issuer cannot repudiate. Such a requesting user can subsequently use such digitally sealed e-credentials to provide elevated identity assurances to other parties. Such proofed and attested to e-credentials can also be used to affix digital seals, including declarations, to electronic documents, including e-credentials and message, that cannot be repudiated by a user applying a digital seal.   

     In summary, the present invention yields the following remarkable capabilities: Collaborating parties are provided assurances that a personal identity device owner is persistently bound to their device including the digitally sealed and issued e-credentials of the owner and the associated encryption keys; that an e-credential, proofed, attested to, and digitally sealed by a personal identity device owner to another user, cannot be repudiated by that owner; that the originator of messages and documents under the originator&#39;s e-credential cannot repudiate having sent them; that the user owning a given credential will be the sole party capable of receiving messages employing that e-credential; and that a personal identity device owner applying one of their e-credentials to digitally seal an electronic document or message, possibly including a declaration of the owner, cannot repudiate having applied their digital seal and declaration to the document or message. 
     Summary of Benefits 
     This electronic identity and credentialing system prevents a wide-range of electronic fraud vulnerabilities, mitigating the risks of identity theft, loss and abuse. The system has been created to support the needs of individual persons to control their identities as well as the needs of enterprises to unambiguously identify consumers, employees, citizens, and other users. 
     This invention specifically satisfies the compelling need for an electronic identity and credentialing system that mimics traditional identities and credentialing in the physical world, and avoids the vulnerabilities and risks of legacy identity systems. The present invention achieves this objective, creating high assurance identities for and among individual persons in the form of electronic credentials (e-credentials) bound to e-credential holders. 
     This electronic identity and credentialing system, by means of an identity engine operable within a personal identity device, strongly binds identifying information of the individual to their electronic credentials which they can subsequently use to unambiguously represent themselves to others over information networks while using their smart phone, tablet computer, laptop computer, or personal computer. 
     Contemplated embodiments described herein integrate smart cards, smart rings, smart watches and smart glasses to elevate identity assurances for citizens and consumers as such enabling technologies emerge. 
     LIST OF REFERENCE CHARACTERS 
     
         
           100  electronic identity and credentialing system 
           101  users with personal identity devices 
           102  smart phone 
           103  tablet computer 
           104  laptop computer 
           105  service providers 
           106  identity services 
           107  transactions between users and service providers 
           108  transactions between users and identity providers 
           109  e-credential requesting user (a requester) 
           110  personal identifying information 
           111  e-credential request 
           112  e-credential issuing user (an issuer) 
           113  issued e-credential 
           114  mutually trusted channel 
           115  if agent, sends e-credential copy to identity provider 
           116  identity service 
           120  personal computer 
           200  personal identity device and identity bindings 
           201  owner (a user) 
           202  personal identity device 
           203  personal identifying information in custody of owner 
           204  identity engine 
           205  custody of device in custody of owner  201   
           206  user interface 
           207  camera 
           208  photographing owner 
           209  photographing personal identifying information 
           210  knowledge-based binding (e.g. password, PIN) 
           211  biometric module 
           212  personal identifying information in custody of owner  201   
           213  protected memory store (ignition key) 
           214  custody of ignition key (removable protected memory store) 
           215  biometric binding 
           216  logical binding between user interface  206  and authentication data  226   
           217  logical binding between biometric module  211  and authentication data  226   
           218  crypto-logical bindings between public and private keys associated with e-credentials of owner  220   
           219  authentication control 
           220  e-credentials of the owner 
           225  public keys embedded in e-credentials of owner 
           226  authentication data 
           227  private keys of e-credential of owner  220   
           230  e-credentials of other users 
           235  public keys embedded in e-credentials of other users 
           240  communications interface 
           245  documents and messages in a personal identity device 
           260  device identifier 
           265  identity engine identifier 
           270  legend: identity bindings 
           275  legend: public-private encryption keys 
           290  other users (issuers) with e-credentials 
           291  digital seals affixed to e-credentials by other users 
           292  digital seal affixed to a document by another user 
           293  cryptographic bindings between issuers  290  and e-credentials of owner  220  and a document  245  by way of digital seals 
           294  digital seals affixed to e-credentials of other users 
           295  digital seal applied to a document using an e-credential of the owner  220   
           296  cryptographic binding by way of a digital seal affixed to a document using an e-credential of the owner  220   
           300  collaboration among users with personal identity devices 
           301  user (requester) 
           302  user (issuer) 
           303  user has an e-credential issued by another party 
           390  collaborating users can establish persistent secure sessions by exchanging e-credentials and using the encryption key pairs associated with their e-credentials 
           392  an issuer  302  attests to the identity of a requester  301  wherein the issuer cannot repudiate having proofed the requester&#39;s identity 
           394  users can use e-credentials proofed and attested to by other parties to establish secure sessions—user  301  provides user  303  an e-credential issued by user  302 , while user  303  provides user  301  an e-credential issued by a different party 
           400  electronic credentials and relationships 
           401  e-credential of an owner (a user) 
           402  default e-credential 
           403  e-credentials of issuers 
           404  e-credentials of other users 
           405  personal identifying information 
           406  digital seals created using e-credentials of issuers 
           407  digital seals affixed to e-credential  401   
           408  e-credential of owner  401  used to issue e-credentials to other users 
           409  digital seals affixed to e-credentials of other users 
           410  self-sealed default e-credential 
           411  e-credential attributes 
           412  owner attributes of the e-credential owner 
           413  each digital seal associated with e-credential issuing record 
           414  e-credential issuing record 
           423  digital sealing image 
           416  three (s) public-private encryption key pairs 
           417  public keys (3) embedded into e-credential  401   
           418  private keys (3) in protected memory store  213   
           440  attributes of e-credential attested by issuer 
           441  attributes of e-credential conferred by issuer 
           442  sign/verify documents and messages 
           443  encrypt/decrypt documents and messages 
           444  embossing key used to create digital seals 
           445  inspection key used to verify digital seals 
           450  credential template (an empty unsealed electronic credential) 
           500  Method for handling digital seals 
           501  an electronic artifact (e.g. document, message, e-credential) 
           503  electronic artifact identifier 
           505  binding between digital seal and electronic artifact using the identifier of the artifact 
           510  attestation of an e-credential owner 
           512  issue date of digital seal (possibly including time) 
           517  e-credential identifier 
           519  affixing a digital seal 
           520  inspecting a digital seal 
           521  e-credential of the owner 
           522  pre-determined identifying attributes of e-credential 
           523  digital sealing image 
           524  inspection key (i) 
           525  embossing key (c) 
           526  pre-determined elements of electronic artifact 
           528  digital seal 
           529  digest 
           530  hash digest function 
           531  hashed digest 
           532  emboss function 
           533  digital seal signature 
           534  affix function 
           540  extract function 
           541  inspect function 
           542  hash result function 
           543  compare function 
           544  result 
           545  hashed result 
           546  expected hash 
           547  “digital seal verified” 
           548  “digital seal failed to verify” 
           600  issuing true copy e-credential of a physical credential 
           601  e-credential requester 
           602  requester takes a photograph of a physical credential 
           603  photograph of physical credential 
           604  physical credential 
           605  e-credential request 
           606  mutually trusted channel established 
           607  e-credential issuer 
           608  identity proofing 
           609  true copy e-credential 
           610  transaction record 
           611  e-credential registry 
           700  issuing true copy self-photograph e-credential 
           701  e-credential requester 
           702  requester takes self-photograph 
           703  e-credential request 
           704  self-photograph 
           705  mutually trusted channel established 
           706  e-credential issuer 
           707  identity proofing 
           709  true copy self-photograph e-credential 
           710  transaction record 
           711  e-credential registry 
           800  issuing an original e-credential 
           801  e-credential requester 
           802  e-credential request 
           803  mutually trusted channel established 
           804  e-credential issuer 
           805  identity proofing 
           806  physical credentials 
           807  e-credential registry 
           808  digital photograph 
           809  issued e-credential 
           811  transaction record 
           900  alternate embodiments 
           901  smart phone 
           902  tablet computer 
           903  laptop computer 
           904  personal computer 
           905  smart card 
           906  smart ring 
           907  smart watch 
           908  smart glasses 
           909  e-credentials of the user including public keys 
           910  mutually trusted channel established 
           911  protected memory store 
           912  private keys and secrets 
           920  user 
           1000  potential scope of electronic credential usage 
           1001  user holding a personal identity device 
           1002  representative e-credential issuing users holding personal identity devices 
           1003  true copy photograph 
           1004  true copy driver&#39;s license 
           1005  diploma 
           1006  employee identifier 
           1007  driver&#39;s license 
           1008  social security number 
           1009  citizenship 
           1010  passport 
           1011  healthcare card 
           1012  debit card 
           1013  credit card 
           1020  friend, family member, colleague, co-worker 
           1021  professional network, social network, professional affiliation, non-profit association 
           1022  notary public, teacher, professor, physician, dentist, certified professional 
           1023  educational institutions 
           1024  employers, enterprises, businesses 
           1025  departments of motor vehicles 
           1026  federal and state institutions 
           1027  financial institutions and banks 
           1028  healthcare providers and insurers 
           1029  e-business merchants and suppliers 
           1100  relating physical credentialing, PKI, PGP and e-credentialing system 
           11 A: Physical Credentialing 
           1101  identifying attributes 
           1102  physical credentials 
           1103  other personal identifying information 
           1104  user 
           1105  physical credential 
           1106  agents 
           1107  credential request 
           1108  agent issues physical credential 
           1109  writes credential and transaction record 
           1110  credential registry 
           11 B: Public Key Infrastructure (PKI) 
           1120  certificate authority (C) 
           1121  signed [digital] certificate, name=C 
           1122  root certificate authority 
           1123  certificate request 
           1124  user X 
           1125  signed digital certificate, name=X 
           1126  signed digital certificate issued 
           11 C: Pretty Good Privacy (PGP) 
           1140  user A 
           1141  user B 
           1142  unsigned digital certificate, name=A (associated with private key) 
           1143  unsigned digital certificate, name=B (associated with private key) 
           1144  unsigned digital certificate, name=A (disassociated from private key) 
           1145  signed digital certificate, name=A 
           1146  private key associated with public key of signed certificate 
           1147  signed digital certificate, name=A (associated with private key 
           11 D: Electronic Identity and Credentialing System 
           1160  user A 
           1161  user B 
           1162  user C 
           1163  personal identity device 
           1164  personal identity device 
           1165  personal identity device 
           1166  first step of round-robin issuing process 
           1167  second step of round-robin issuing process 
           1168  third step of round-robin issuing process 
           1169  default credential, name=default 
           1170  e-credential request, name=A (associated with private keys) 
           1171  default e-credential embossing key digitally seals request 
           1172  e-credential request, name=A (disassociated from private keys which are thereby not revealed) 
           1173  sealed e-credential, name=A (sealed by user A and user B) 
           1174  newly issued e-credential 
           1175  digital seal of user B applied 
           1176  digital seal of user C applied 
           1177  embossing key of selected credential digitally seals issued e-credential (e.g. default e-credential) 
       
    
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       The following figures show embodiments according to the inventive subject matter, unless noted as showing prior art. 
         FIG. 1  is a system diagram depicting users holding personal identity devices, communicating with identity services and service providers, and relationships between users, personal identifying information, and electronic credentials. 
         FIG. 2  is a diagram depicting an owner&#39;s personal identity device including personal identifying information, pre-installed identity engine, e-credentials retained within the identity engine, a protected memory store, known as an ignition key if removable, other users of personal identity devices, identity services, service providers, and various physical, knowledge-based, biometric, logical, and crypto-logical bindings among the artifacts comprising a personal identity device, as well as bindings with other users of personal identity devices. 
         FIG. 3  is a diagram depicting collaboration among users requesting, issuing, holding and using e-credentials. 
         FIG. 4  is a diagram depicting electronic credentials of users (e-credential owners), including attached personal identifying information, a default e-credential, and an e-credential template, the figure also depicting relationships between e-credentials of issuers and an e-credential owner, and e-credentials issued by an e-credential owner to other users of personal identity devices. 
         FIG. 5  is a diagram depicting Method for Handling Digital Seals. 
         FIG. 6  is a usage scenario diagram illustrating the creating of an e-credential with an attached photocopy of the physical credential thereby issuing of a true copy of a physical credential. 
         FIG. 7  is a usage scenario diagram illustrating the creating of an e-credential with an attached self-photograph, thereby issuing of a true copy of a self-photograph, and possibly creating an electronic business card. 
         FIG. 8  is a usage scenario diagram illustrating the issuing of an original electronic credential, for example, an electronic driver&#39;s license or banking card embedded in the user&#39;s personal identity device. 
         FIG. 9  depicts alternate embodiments of the electronic credentialing system that can be expected to emerge in the future. 
         FIG. 10  depicts the potential scope of applications and services that could benefit from deployments of the electronic identity and credentialing system in various economic sectors. 
         FIG. 11  relates physical credentialing, Public Key Infrastructure, Pretty Good Privacy (PGP), to the electronic identity and credentialing system. 
     
    
    
     DETAILED DESCRIPTION 
     Representative embodiments according to the inventive subject matter are shown in  FIGS. 1 to 11 , wherein similar features share common reference numerals. The specific embodiments are meant to be illustrative and not limit the scope of the invention and the various ways it may be embodied. 
     The inventive subject matter is an electronic credentialing system which includes personal identity devices of users [persons] capable of requesting and issuing electronic credentials, as well as exchanging electronic credentials over the web with identity services and service providers. A personal identity device is an adapted mobile computing device such as a smart phone, a tablet computer, a laptop computer, or personal computer with a pre-installed identity engine and a protected memory store. Users have physical credentials in their custody, and electronic credentials (e-credentials) maintained within the identity engine of their personal identity device(s). The protected memory store contains secrets including PINs, passwords, and passphrases of the device owner. An embodiment of a personal identity device could include a trusted execution environment to establish a trust zone to shield the identity engine and protected memory store from un-trusted software components. 
     A requesting user can submit an e-credential request to another user, the issuer, who proofs personal identifying information provided by the requester, digitally seals the e-credential including a declaration of the issuer, and returns the digitally sealed e-credential to the requester. Acquiring an attested to e-credential requires a requester to arrange an encounter [a session or meeting], or possibly a series of encounters, with issuer(s) to vet the requester by proofing their personal identifying information, for example, by matching the requester to the photograph and signature on their driver&#39;s license, and by asking probing questions to ferret out imposters. An in-person encounter is said to be one where the identity of the requester is proofed by the issuer face-to-face, typically in a private area. Online identity proofing can be conducted, for example, by way of audio-video conferencing (e.g. Skype) or telephone, wherein personal identifying information is submitted electronically. Online identity proofing appears to be more vulnerable to electronic fraud than in-person proofing. However, this disadvantage is mitigated when the requester is well-known by the issuer and the online encounter is conducted over a mutually trusted communications channel. 
     During operational use, users of personal identity devices can use them to collaborate with other device users as well as with identity services and service providers. E-credentials obtained from other users are retained by the identity engines.  FIG. 1  Depicting Scope of Electronic Identity and Credentialing System 
     Now referring to  FIG. 1 , which depicts the electronic identity and credentialing system  100  including users with personal identity devices  101  including smart phones  102 , tablet computers  103 , laptop computers  104 , and personal computers  120 .  FIG. 1  also depicts service providers  105  and identity services  106 , transaction flows between users and service providers  107 , and transactions between users and identity services  108 . Additionally, the figure illustrates an e-credential (electronic credential) requesting user  109  (a requester), holding personal identifying information  110 , submitting an e-credential request  111  to an e-credential issuing user  112  (an issuer), who issues an e-credential  113  to the requester  109  by way of their smart phones  102 . If the issuer is an agent of an identity service  116 , the issuing agent sends a copy  115  of the issued electronic credential  113  to identity service  116 . 
     Now referring to  FIG. 2 , this diagram depicts a personal identity device and identity bindings  200  composing the system. Legend  270  of  FIG. 2  depicts five (5) types of bindings: physical, knowledge-based, biometric, logical, and cryptographic (crypto-logical) bindings. The identity bindings among artifacts of the system provide assurances that e-credentials of the owner are strongly bound to the identity owner, and not to any other owner. 
       FIG. 2  depicts an owner  201  (a user), personal identity device  202  of the owner, personal identifying information  203  (e.g. utility bills, certificates, driver&#39;s licenses) in the custody  212  of owner  201 , and communications interface  240  to other users with personal identity devices  101 , to remote identity services  106 , and to remote service providers  105 . Personal identity device  202  is bound to the device owner  201  by way of physical custody  205  and authentication bindings  210  and  215  protecting against possible loss of custody  205 . A personal identity device  202  also contains documents and messages  245 . This figure additionally shows other users (issuers)  290  with e-credentials having affixed digital seals  291  to e-credentials  220  of the owner and digital seal  292  affixed to a document or message  245 . 
     A personal identity device  202  has an identity engine  204  that holds e-credentials (electronic credentials) of the owner  220  and e-credentials of other users  230 . Identity engine  204  controls a protected memory store  213  and possibly has a digital camera  207 . Identity engine  204  specifies an e-credential of the owner  220  specified by owner  201  entering personal identifying information  203  captured  210  by way of user interface  206 , by attaching self-photographs  208 , and by attaching photographs  209  of the owner&#39;s personal identifying information  203 . Certain embodiments may have a device identifier  260  and an identity engine identifier  265 . 
     User interface  206  is also capable of performing knowledge-based authentication and storing knowledge-based authentication data  226 , including PINs, passwords and PIN/password hashes, in the protected memory store  213 . The personal identity device  202  possibly has a biometric module  211  performing biometric authentication, storing biometric authentication data  226 , including finger print, iris, facial and other biometric minutia, in protected memory store  213 . Authentication data  226  stored in protected memory store  213  is controlled (encapsulated) by identity engine  204 . 
     By encapsulating the authentication data, the identity engine  204  logically binds the device owner  201  to the owner&#39;s e-credentials  220  controlled by identity engine  204 :
         (a) Identity engine  204  implements logical binding  216  to bind the device owner  201 , via user interface  206 , to the associated knowledge-based authentication data  226  in protected memory store  213 . Owner  201  is thereby logically bound to their personal identity device  202 , as well as by means of physical custody  205 .   (b) If personal identity device  202  has a biometric module  211  biometrically binding owners  201  to biometric module  211  and hence to personal identity device  202 , identity engine  204  can employ logical binding  217  to bind biometric module  211  to associated biometric authentication data  226  in protected memory store  213 . Owner  201  is thereby additionally bound to device  202  and identity engine  204 .   (c) To detect possible loss of custody  205 , identity engine  204  can use authentication control  219  to cause user interface  206  and biometric module  211  to re-authenticate the user thereby verifying that device owner  201  is persistently in control of their personal identity device  202 .       

     If protected memory store  213  can be removed by device owner  201 , owner  201  can physically break logical binding  216  thereby disabling authentication by means of user interface  206  and biometric module  211 , disabling identity engine  204  and thereby preventing other users from masquerading as personal identity device owner  201 . Owner  201  can subsequently re-enable their identity engine  204  by re-attaching protected memory store  213 . When a removable memory store  213  is removable, it is called an “ignition key”. 
     Associated with an e-credential of the owner  220  are three (3) public-private encryption key pairs, the pairs being crypto-logically bound  218  (see glossary) to each other, where the three (3) public keys  225  of each pair are embedded in the e-credential  220  of the owner, and the corresponding three (3) private keys  227  of each pair are embedded into removable memory store  213  controlled by identity engine  204 . Legend  275  identifies the six (6) types (3 pairs) of public-private encryption keys associated with an e-credential. If protected memory store  213  is removable (is an “ignition key”), public-private key crypto-logical bindings  218  are broken when ignition key  213  is removed thereby disabling identity engine  204  and enabling owner  201  to have custody  214  of protected memory store  213  including contained secrets of owner  201 , namely, authentication data  226  and private encryption keys  227 . 
     By way of communications interface  240 , identity engine  204  can provision e-credentials of the device owner  220  to other users  101 , to identity services  106 , and to service providers  105 . When so provisioned, public keys  225  embedded in an e-credential of the owner  220  are available to other collaborating parties (users and services). The paired private keys  227  within protected memory store  213  are not revealed by the identity engine  204  of the owner to other users. 
     By way of communications interface  240 , identity engine  204  can acquire e-credentials of other users  230 , and from identity services  106 . E-credentials of other users  230  have embedded public encryption keys  235 . However, the private keys paired with public keys  235  are not disclosed by the personal identity devices  202  and contained identity engines  204  of other users  101 . 
     Cryptographic operations, associated with the encryption keys of a selected e-credential  220  of an owner provided to other parties, are bound to device owner  201  as follows (see legend  275 ):
         (a) Digital signing key s, a private key in  213  associated with e-credential  220  of the owner, can be used by identity engine  204  of owner  201  to calculate, by means of a prior art encryption algorithm, a digital signature over a message, document or e-credential. Because  216  and  217  logically bind s to owner  201 , and because s is crypto-logically bound  218  to verification key v, a public key  225  embedded in e-credential  220 , other parties having  220  can use verification key v to verify that the digital signature applied to the message, document or e-credential must have been originated by owner  201 ;   (b) Encryption key e, a public key embedded in e-credential  220  provided by owner  201 , can be used by other parties, by means of a prior art encryption algorithm, to encrypt messages and documents sent to owner  201 . Because the matching decryption key d, a private key  227  in  213 , is logically bound by  216  and  217  to owner  201 , and d is crypto-logically bound  218  to e, other parties having e-credential  220  can use e to encrypt electronic credentials, documents and messages that can only be decrypted by owner  201  thereby providing assurances that only owner  201  can read them;   (c) Embossing key £, a private key in  213  associated with the e-credential of owner  201 , can be used by the owner, by means of the present invention&#39;s digital sealing embossing and inspecting method (see  FIG. 5 ), to calculate and render a digital seal, and affix a digital seal ( 291 ,  292 ,  294 ,  295 ) to an electronic credential, document or message. Because  216  and  217  logically bind £ to owner  201 , and because £ is crypto-logically bound  218  to inspection key i (a public key  225  embedded in e-credential  220 ), other parties having e-credential  220  can use inspection key i to verify that the digital seal applied to the message, document or e-credential must have been created and affixed by owner  201 .       

       FIG. 2  also illustrates other users  290 , having personal identity devices and e-credentials, respectively affixing digital seals  291  and  292  to e-credentials  220  and an electronic document  245 , thereby creating cryptographic bindings between the e-credentials of other users (issuers)  290  and e-credentials  220  of the owner, and documents and messages  245  contained in personal identity device  202  of owner  201 . Described further in  FIGS. 3, 4 and 5 , a digital seal, by means of the embossing key £ of an e-credential of an owner, crypto-logically binds the identity of the owner, including an attestation (a declaration) specified by the owner, to an electronic artifact such that the owner cannot repudiate having affixed the digital seal to the attestation (declaration) and electronic artifact. Other parties can use the paired inspection key i of the e-credential to verify the digital seal. When another user  290  selects one of their e-credentials to create a digital seal, affixing the digital seal to an e-credential  220  of owner  201 , the non-repudiation property of the affixed digital seal provides elevated assurances to other parties that the personal identifying information specified by e-credential  220  is that of owner  201 , and not of some other e-credential owner. 
     Now referring to  FIG. 3 , this figure depicts collaboration among users with personal identity devices  300 .  FIG. 3  depicts three (3) personal identity devices of  FIG. 2  collaborating with each other.
         1)  FIG. 3  depicts scenarios wherein three users  301 ,  302  and  303 , have personal identity devices  202  with pre-installed identity engine  204 , each user  301 ,  302  and  303  respectively having e-credentials EC n , n=1, 2, 3 wherein EC n , has embedded public keys v n , e n  and i n  respectively paired with private keys s n , d n  and ε n  retained in protected memory store  213 . E-credentials, EC n , n=1, 2, 3 are possibly digitally sealed.   2) During any given collaboration session, the identity engine of user  301  can request the identity engine of user  302  to re-authenticate user  302  by means of authentication control  219 , returning a confirmation message to user  301  verifying that user  302  is persistently connected to the personal identity engine  204  of user  302 .   3) Using their identity engines  204 , users  301  and  302  establish a persistent secure session  390  as follows:   a) Users  301  and  302  digitally sign EC 1  and EC 2  using s 1  and s 2  respectively, and exchange these signed e-credentials.   b) Users  301  and  302  respectively apply v 1  and v 2  embedded in EC 2  and EC 1  to verify the digital signatures applied to each e-credential.   c) If the digital signatures applied to EC 1  and EC 2  successfully verify under v 1  and v 2 , users  301  and  302  can respectively apply e 2  of EC 2  and e 1  of EC 1  to encrypt messages sent to the other user, user  302  employing d 2  of EC 2  and user  301  using d 1  of EC 1  to decrypt received messages from users  301  and  302  respectively.   d) Having executed 3) a), b) and c), users  301  and  302  have assurances that they are persistently bound to each other and are communicating over a secure channel. However, neither user can be certain that the identifying information specified in the credential provided by the other user actually represents that user, that is, the risk of user masquerade has not been eliminated.   4) E-credential issuer  302  attests to the identity of e-credential requester  301  over a persistent secure session  392 . Users  301  and  302  use their identity engines  204 , executing step 3 above, to exchange e-credentials EC 1  and EC 2 , thereby establishing a persistent secure session  390 . User  301  (the requester) acquires a digitally sealed e-credential from user  302  (the issuer) as follows:   a) In addition to EC 1 , requester  301  provides personal identifying information  203  to issuer  302 . EC 1  may be unsealed or previously sealed with one or more (multiple) digital seals affixed.   b) Issuer  302  proofs requester  301  against the provided personal identifying information  203  and the contents of EC 1 , possibly asking probing questions, thereby verifying that EC 1  unambiguously represents the identity of requester  301 . This is called “identity proofing”.   c) If requester  301  is successfully proofed, issuer  302  uses their identity engine  204  to affix a declaration (e.g. “proofed”) to EC 1 , uses embossing key ε 2  of EC 2  to create and affix a digital seal to EC 1 , and returns newly sealed e-credential EC 1  to requester  301 .       

     Having completed steps 4) a), b) and c), issuer  302  thereby attests to the identity of requester  301  which attestation issuers  302  cannot repudiate because the digital seal under embossing key ε 2  cryptographically binds the identity of issuer  302  to the identity of the requester  301 .
         5) Users  301  and  303  exchange and use e-credentials proofed and attested to by 3 rd  parties to establish secure sessions  394 . E-credential EC 1  of user  301  has been digitally sealed and issued by user  302  (per  392 ); and e-credential EC 3  of user  303  has been digitally sealed by the local bank manager, a notary public, of user  303 . Users  301  and  303  are not known to each other and wish to establish a secure session between them. To achieve appropriate identity assurances, they employ their identity engines  204  to execute the following steps:   a) Executing steps 3) a), b) and c), (see  390 ) users  301  and  303  use e-credentials EC 1  and EC 3  to establish a persistent secure session between them wherein neither user is initially certain that the identifying information specified in the credential provided by the other user actually represents the other user.   b) However, users  301  and  303 , by means of their identity engines, observe that e-credentials of the other user (EC 1  and EC 3 ) have been proofed and digitally sealed by 3 rd  parties:
           i) User  301  uses i 3  of EC 3  to inspect and verify the digital seal applied to EC 3  and thereby becomes satisfied that the issuer (the bank manager) is sufficiently trusted to believe that the identity specified by EC 3  is that of user  303 .   ii) Similarly, user  303  uses i 1  of EC 1  to inspect and verify the digital seal applied to EC 1  and thereby becomes satisfied that issuer  302  is sufficiently trusted to believe that the identity specified by EC 1  is that of user  301 .   
           c) Given these assurances, users  301  and  303  can proceed with their session with assurances that they are communicating with a sufficiently qualified collaborator.       

     By way of steps 1 to 5, identity assurances are provided among collaborating parties whereby a user with a personal identity device: is persistently bound to their device and the digitally sealed and issued e-credentials contained therein; is able to determine that an e-credential provided by a remote user must have been originated by that user; can determine that messages originated under this e-credential cannot be repudiated; can verify that the originating user is the sole party capable of reading messages employing that e-credential. An e-credential owner can also affix digital seals to e-credentials, documents and messages that can be verified (“inspected”) by other users wherein the user creating and affixing such seals cannot repudiate having digitally sealed them. 
     Now referring to  FIG. 4  depicting electronic credentials (e-credentials) and relationships  400  described at various levels of detail including: an e-credential  401  of an owner (a user), an e-credential template  450 , a default e-credential of the subject owner  402 , e-credentials of issuers  403 , e-credentials of other users  404 , and personal identifying information  405  of the owner. Depicted electronic credential  401  is an exemplar information structure for other credentials including e-credential template  450 , default e-credential  402 , e-credentials of issuers  403 , and e-credentials of other users  404  (other users can also be issuers, for example, when users cross-issue e-credentials to each other). 
       FIG. 4  depicts various relationships including the e-credential of the owner  401  referencing attached personal identifying information  405 ; e-credentials of issuers  403  having been used to create, affix and issue  406  digital seals  407  to e-credential  401 ; and e-credential  401  having been used to create, affix and issue  408  digital seals  409  to e-credentials of other users  404 . Depicted default credential  402  represents a digitally self-sealed  410  e-credential that can be used to seal and issue e-credentials and electronic documents. 
     E-credential of the owner  401  has e-credential attributes  411  including an e-credential identifier, issue date, expiry date, and credential type, these elements specified when e-credential  401  was created. The e-credential additionally specifies attributes of the owner  412  including name(s) and identifier(s), distinguishing features (physical attributes of the subject owner), life events (e.g. birth, marriage, and divorce dates), endorsements, restrictions, and attached (personally) identifying information. For every digital seal  413  affixed to e-credential  401 , an issuing record  414  is created by the issuer specifying the conditions under which the digital seal was created including: the encounter date(s); the types of encounters (in-person, online); the number of years that the subject has been known to the issuer; relevant certifications and qualifications of issuer (e.g. vetting and proofing experience, professional obligations, notarization qualifications); jurisdiction, policies and procedures applicable the issuing encounter; references to the documents that were proofed, if any; the attributes of the e-credential owner that were attested to by issuer  440 ; and attributes of the subject, if any, that were conferred upon the e-credential owner by issuer  441 . 
     Every e-credential  401  issued also specifies a digital seal image  423  and is associated with three (3) public-private key pairs  416  where public keys  417  are embedded into e-credential  401 , and where the paired private keys  418  are in protected memory store  213  of the owner&#39;s personal identity engine  202 , said public-private key pairs including a signing-verification key pair used to create and verify digital signatures applied to documents and messages  442 ; an encryption-decryption key pair used to encrypt and decrypt documents and messages  443 ; and an embossing-inspection key pair used in conjunction with the digital seal image  423  where the embossing key is used to create digital seals  444 , and the inspection key is used to verify digital seals  445 . 
       FIG. 5  depicts a method for handling digital seals  500  applied to electronic artifacts including e-credentials, documents and messages. Functions for affixing a digital seal  519  and inspecting a digital seal  520  are depicted. Affixing a digital seal  519  is comprised of a hash digest function  530 , an emboss function  532  and an affix function  534 . Inspecting a digital seal  520  is comprised of an extract function  540 , an inspect function  541 , a hash result function  542  and a compare function  543 . 
     Affixing a digital seal  519  creates and affixes a digital seal to electronic artifact  501  by: 
     
         
         
           
             a) selecting an e-credential  521  of the owner and pre-determined attributes  522  of e-credential, including at least the e-credential identifier  517 , the digital sealing image  523  and the private embossing key  525 ; 
             b) selecting pre-determined elements  526  of the electronic artifact  501 , including at least the electronic artifact identifier  503 ; 
             c) the e-credential owner specifying an attestation  510  and issue date  512  characterizing the electronic artifact; 
             d) concatenating  510 ,  512 ,  522  (including at least  517 ),  523  and  526  (including at least  503 ) yielding digest  529 ; 
             e) using hash digest  530  to yield hashed digest  531 ; 
             f) using emboss  532  and the embossing key  525 , a private encryption key, to encrypt the hashed digest  531  yielding digital seal signature  533 ; 
             g) using affix  534  to combine the digital sealing image  523 , attestation  510 , issue date  512 , the e-credential identifier  517 , electronic artifact identifier  503 , and digital seal signature  533 , rendering digital seal  528 , and then affixing  528  to the electronic artifact  501  by using the electronic artifact identifier  503  to logically bind  505  the digital seal  528  to the electronic artifact  501 ;
 
Inspecting a digital seal  520  extracts and verifies digital seal  528  affixed to artifact  501  by:
 
             a) using extract  540  to extract from digital seal  528 , the attestation  510 , the issue date  512 , e-credential identifier  517 , electronic artifact identifier  503 , and digital seal signature  533 , subsequently acquiring pre-determined identifying attributes  522 , inspection key  524 , and pre-determined elements  526 ; 
             b) concatenating  510 ,  512 ,  522 , (including at least  517 ),  523 ,  526  (including at least  503 ), yielding result  544 ; 
             c) applying hash result  542  to result  544  yielding hashed result  545 ; 
             d) using inspect  541  and the inspection key  524  to decrypt the extracted digital seal signature  533  yielding expected hash  546 ; and 
             e) using compare  543  to match hashed result  545  to expected hash  546  indicating “digital seal verified”  547  if  545  and  546  match, else indicating “digital seal failed to verify”  548  if  545  and  546  do not match. 
           
         
       
    
       FIG. 6  depicts a usage scenario illustrating the issuing of a true copy e-credential of a physical credential  600  such as a driver&#39;s license. E-credential requester  601  uses their personal identity device  202  to take  602  a digital photograph  603  of a physical credential  604  (e.g. requester&#39;s driver&#39;s license). By means of the requester&#39;s personal identity device  202 , requester  601  prepares an e-credential request  605  by populating an e-credential template  450  and attaching digital photograph  603  to request  605 . By means of a mutually trusted channel  606  submits request  605  to the personal identity device  202  of a e-credential issuer  607 . By means of an in-person or online encounter, issuer  607  performs identity proofing  608  of recipient  601  with respect to the submitted e-credential request  605  and the attached digital photograph  603  of physical credential  604 , and other personal identifying information that may be required. Finally, upon successful identity proofing, issuer  607 , by means of the issuer&#39;s personal identity device  204 , issues a true copy e-credential  609  of physical credential  604  to the personal credentialing device  202  of the requester  601 , and writes a copy of the true copy e-credential  609  and a transaction record  610  to an e-credential registry  611 . 
       FIG. 7  depicts a usage scenario illustrating the issuing of a true copy self-photograph e-credential  700 , for example, one associated with other personal identifying information to create an electronic business card. The e-credential requester  701  uses their personal identity device  202  to take  702  a digital self-photograph  704 . By means of the requester&#39;s personal identity device  202 , requester  701  prepares an e-credential request  703  by populating an e-credential template  450  and attaching the digital self-photograph  704  to request  703 . By means of a mutually trusted channel  705 , requester  701  submits request  703  with attached digital self-photograph to the personal identity device  202  of e-credential issuer  706 . By means of in-person or online encounter, issuer  706  performs identity proofing  707  of recipient  701  with respect to submitted e-credential request  703 , the attached self-photograph  704 , and other personal identifying information that may be required. Finally, upon successful identity proofing, issuer  706 , by means of the issuer&#39;s personal identity device  202  and the mutually trusted channel  705 , issues a true copy self-photograph e-credential  709  to the personal identity device  202  of requester  701 , and writes the true copy self-photograph e-credential  709  and a transaction record  710  to e-credential registry  711 . 
       FIG. 8  depicts a usage scenario illustrating the issuing of an original electronic credential (e-credential). The e-credential requester  801  uses their personal identity device  202  to populate an e-credential template  450  to prepare an e-credential request  802 . By means of mutually trusted channel  803 , requester  801  submits request  802 , possibly attaching other relevant personal identifying information, to issuer  804  by way of the issuer&#39;s personal identity device  202 . By means of an in-person or online identity encounter, issuer  804  performs identity proofing  805  of requester  801  with respect to the submitted request  802 , other personal identifying information that may be attached including physical credentials  806  that may be required, and personal identifying information that may be retrieved from the issuer&#39;s e-credential registry  807 . Upon successful identity proofing, issuer  804  uses their personal identity device  202  to take a digital photograph  808  of requester  801 , attaches the digital photograph to the submitted e-credential request  802 , digitally seals e-credential request  802  thereby creating new e-credential  809 . Finally, issuer  804 , by means of the issuer&#39;s personal identity device  202  and mutually trusted channel  803 , sends digitally sealed e-credential  809  to the personal credentialing device  202  of requester  801 , and writes a copy of e-credential  809  and transaction record  811  to e-credential registry  807 . 
       FIG. 9  depicting alternate embodiments  900 , includes a user  920 , a smart phone  901 , a tablet computer  902 , a laptop computer  903 , and a personal computer  904 . Persons skilled in the art will recognize that many hardware and software variations, configurations and deployments of the inventive subject matter are possible. For example, various biometric mechanisms, digital camera configurations, and operating systems may be configured for any given personal identity device. 
       FIG. 9  also depicts possible future embodiments that could be developed and integrated to support the installation and deployment of the inventive subject matter including a smart card  905 , a smart ring  906 , a smart watch  907 , and smart glasses  908 . For example, instead of being maintained within a single personal credentialing device  202  (e.g. smart phone  901 ), the user&#39;s e-credentials  909  with embedded public keys, paired with private keys  912  in protected memory store  911  could be otherwise deployed.  FIG. 9  depicts user  920  having a smart phone  901  communicating over pre-configured trusted communication channels  910  with a smart card  905  or a smart ring  906  with embedded protected memory store  911  containing private keys and secrets  912  of user  920 .  FIG. 9  also depicts a smart watch  907  containing e-credentials  909  of user including embedded public keys. Smart glasses  908  could be similarly created and integrated with a smart phone  901 . For example, the smart glasses  908  could (i) retrieve private keys  912  from the smart ring  906 , (ii) read an encrypted page into the smart glasses  908 , (iii) decrypt the page; and (iv) render the decrypted page in plain text on the inner surface of the smart glasses  908  for user  920  to read. Such an embodiment avoids decryption of documents within the user&#39;s personal identity device, thereby decreasing the risk of document tampering. Another embodiment would be for e-credentials of the user  909  and private keys  912  to be maintained in smart card  905  communicating with the user&#39;s smart phone  901 . Those skilled in the art will recognize that segmenting the artifacts of the inventive subject matter among distinct hardware devices reduces identity theft risk. 
       FIG. 10  depicts the potential scope of electronic identity and credentialing usage  1000 . This figure shows user  1001  holding a personal identity device  204  containing a group of electronic credentials  1003  to  1013  issued to user  1001 . This figure also shows representative credential issuers  1002  holding personal credentialing devices who have issued electronic credentials to user  1001 . Grouping  1020  represents individual users who can issue simple e-credentials to user  1001  such as true copy photographs  1003 . Grouping  1022  represents individual users with elevated qualifications and obligations sufficient, for example, to issue certified true copies of driver&#39;s licenses. Grouping  1021  represents organizations and networks without credential issuing agents that nevertheless accept electronic credentials  1003 ,  1004  and  1007 . Groupings  1023  to  1028  represent institutions and organizations having credentialing agents (authorities) charged with issuing e-credentials to employees, customers and the public. The example of departments of motor vehicles (DMVs)  1025  illustrates wide dissemination and usage of electronic driver&#39;s licenses across most groupings. Grouping  1029  represents e-business merchants and suppliers who mainly leverage electronic credentials issued by the credential issuers of the other groupings. 
     Now referring to  FIG. 11  relating physical credentialing, prior art PKI and PGP technologies, and e-credentialing system  1100 .  FIG. 11A  depicts a physical credentialing system;  FIG. 11B  depicts prior art Public Key Infrastructure (PKI);  FIG. 11C  depicts prior art Pretty Good Privacy (PGP); and  FIG. 11D  depicts the inventive subject matter, an electronic identity and credentialing system. 
       FIG. 11A  depicts a physical credentialing system illustrating the range of identifying attributes  1101  of a person mapped to physical credentials  1102  and other personal identifying information  1103  of a user  1104 . When requesting physical credential  1105 , the user  1104 , submits their existing physical credential(s)  1102  and other identifying information  1103  to an agent  1106  of the credential issuing organization, together with a credential request  1107  (a completed application form) specifying selected identifying attributes  1101  of the user to the agent  1106 . The agent  1106  proofs the provided information, issues  1108  credential  1105  to the user  1104 , and writes transaction record  1109  into the credential registry  1110 . 
       FIG. 11B  depicts a Public Key Infrastructure (PKI) usage scenario wherein a certificate authority (C)  1120 , an identity provider, possesses a signed (digital) certificate  1121  with public key q c , matching private key p c , with digital signature ds r  signed and issued by root certificate authority  1122 . In response to a certificate request  1123  from user X  1124 , certificate authority (C)  1120  generates, signs, and issues  1126  to user  1124  a signed (digital) certificate (name=X)  1125  with public key q x , private key p x , and digital signature ds c  calculated using signed digital certificate  1121  of certificate authority  1120 . 
       FIG. 11C  depicts a Pretty Good Privacy (PGP) usage scenario where user A  1140  requests user B  1141  to digitally sign and return user A&#39;s digital certificate. Initially, using installed PGP software, user A creates an unsigned digital certificate (name=A)  1142  containing public key q a  paired with private key p a  stored outside the context of certificate  1142 . User B similarly creates an unsigned digital certificate (name=A)  1143  containing public key q b  paired with private key p b  stored outside the context of certificate  1143 . On an ad hoc basis, user A and user B agree to exchange digital certificates, for example, by secure email using pre-determined symmetric encryption keys. User A sends unsigned digital certificate  1144  to user B (private key p a  is not sent to user B) requesting user B to digitally sign user A&#39;s digital certificate. User B, upon receiving user A&#39;s digital certificate  1144 , uses user B&#39;s private key p b  to digitally sign user A&#39;s digital certificate  1144 , calculating and affixing digital signature ds b  to user A&#39;s digital certificate and subsequently sending the signed digital certificate  1145  to user A. The PGP software finally associates  1146  private p a  with the newly signed digital certificate  1147 . 
       FIG. 11D  depicts a usage scenario of the present invention, namely, an electronic identity and credentialing system. This figure illustrates user A  1160 , user B  1161  and user C  1162  using their respective personal identity devices  1163 ,  1164 ,  1165  to request and issue an e-credential for user A, wherein user A requests an e-credential, and both user B and user C issue a new e-credential to user A following a round-robin issuing process  1166 → 1167 → 1168 . After installation and setup, the personal identity devices of users A, B and C each contain a self-sealed default e-credential  1169  with digital sealing image, public keys, and associated private keys ( FIG. 11D  only depicts the default e-credential  1169  of user A). User A completes an e-credential request  1170  initialized with digital sealing image, public keys, and associated private keys, specifying selected attributes of the user, possibly attaching other personal identifying information, and then selecting default credential  1169  to digitally seal  1171  e-credential request  1170 . User A subsequently sends ( 1166 ) the e-credential request  1172  (not including private keys) to user B. User B verifies digital seal  1171  of e-credential request  1170 , proofs user A against the contents of e-credential request  1170 , and if verified, calculates and affixes digital seal (dŝ b ) to e-credential request  1170 . User B then forwards ( 1167 ) the partially sealed and issued e-credential, to user C who follows the same proofing and verification steps as user B, affixing a digital seal (dŝ c ) and issuing ( 1168 ), now doubly sealed e-credential  1173 , to user A. Upon receiving newly issued e-credential  1173 , the original e-credential request is replaced by the newly created e-credential, digitally sealed by a selected e-credential of the requester (e.g. default credential  1169 ) (thereby becoming triply sealed  1171 ), and the private keys originally associated with the e-credential request are re-associated with the newly issued e-credential  1174 . 
     The present invention provides several improvements and advantages over prior art PKI and PGP identity systems including:
         (a) Private keys are never revealed outside the context of the user&#39;s personal identity device, while PKI certificate authorities allow the distribution of private keys over networks;   (b) Supports e-credentials that can contain a range of personal identifying information while PKI and PGP digital certificates can specify only names and identifiers;   (c) Enables an e-credential owner to be crypto-logically bound to their e-credential by three (3) encryption key pairs while PKI and PGP digital certificates specify only a single key pair;   (d) E-credentials support three (3) public-private key pairs used for distinct purposes while PKI and PGP digital certificates allow sharing a single encryption key across multiple applications;   (e) By means of digital sealing, an e-credential issuer cannot repudiate having issued an e-credential. Digital signatures applied to PKI and PGP digital certificates can be repudiated;   (f) An owner&#39;s personal identity device logically binds the owner&#39;s authentication data to their e-credentials and hence to the owner. PKI and PGP do not support such binding mechanisms;   (g) The present invention supports 3 rd  party attestation of e-credentials among device owners. PKI provides only server-centric attestations;   (h) Provides a mechanism for personalizing and visualizing a digital seal applied to e-credentials, documents and messages. PKI and PGP do not specify such mechanisms.
 
Disadvantages
   (a) Personal identity devices are not normally shared while desktops and laptops are commonly shared. Tablet computers and smart phones are less likely to be shared. Given the risks of sharing, personal identity devices should not be shared.   (b) The present invention does not describe how the system will be integrated with identity services and service providers, or how the inventive subject matter can be transitioned from prior art identity systems such as public key infrastructure based systems. These tasks are left to others to solve.   (c) The inventive subject matter is more complex than the cited relevant prior art. Although the additional effort required for deployment and operation may appear to be a disadvantage, it is believed that the benefits of reduced identity theft and electronic fraud will off-set this apparent disadvantage.       

     During the discovery effort, several meaningful insights into electronic identity and credentialing emerged, leading to unanticipated discoveries and novel features that enhanced the utility of the present invention. For example, the initial phase of the discovery process did not anticipate the potential of digital cameras embedded into a user&#39;s personal identity device. Nor did it consider applying some of the practices of notary publics when proofing personal identifying information. 
     Digital Sealing Method: Notary practices stimulated the discovery of the present invention&#39;s method for digitally applying seals to e-credentials and other electronic documents. The notary&#39;s process suggested a powerful technical solution that can also be rendered programmatically. This discovery process began by observing that a notary public, after proofing a document, uses their embosser (a stamping device) to impress their seal onto documents to be notarized. The purpose of the seal is to detect tampering with both the document and the seal itself. The notary&#39;s impressed seal is also useful to trace the proofing and sealing event back to the notary&#39;s registry. This manual process motivated the creation of the present invention&#39;s digital sealing method whereby the issuer&#39;s embossing key is used to create a digital seal signature that cryptographically binds and protects both the sealed document and the seal, containing selected attributes of the issuer, against tampering. The inspection key, a public key paired with the embossing key, is used to verify the digital seal signature to detect both tampering with the seal and the document. Because these keys are bound to the e-credentials of the owner, an issuer using their embossing key when digitally sealing a document, cannot repudiate having applied this key, and hence the seal. 
     Personalized Digital Seals: It was observed that a notary&#39;s seal includes a commission number, expiry date, jurisdiction, and possibly other identifying attributes of the notary. Furthermore, because notary is licensed by a given jurisdiction, seals often incorporate images such as state animals, flowers, landmarks. This motivated the idea of personalizing digital seals by enabling the specification of a “sealing image” [e.g. a jpg or bitmap] for every credential. Furthermore, the digital sealing process was enhanced by including the sealing image in the calculation of the digital seal signature, thereby protecting the seal image as well as the document and the contents of the seal, containing selected attributes of the issuer, from tampering. This technical feature enables visualization improvement opportunities. For example, software renderings of a cryptographically bound sealing image (e.g. photos, logos, written signatures), if tampered with, could be rendered with a strong warning and prevent certain operations that might put the user at risk. 
     Notaries and Integrated Digital Cameras: Examining the best practices of Notary Publics combined with the photographic capabilities of mobile computing devices stimulated unanticipated new types of electronic credentials that exploit front-facing and forward-facing cameras. It was derived from the process of certifying true copies of legal documents [e.g. birth certificates and citizenship papers] and application of the notary&#39;s embosser to impress the notary&#39;s seal onto the document. 
     Certified True Copy E-Credentials: This refinement of the present invention involves the application of the forward-facing camera of a mobile device: taking a digital photograph of a physical credential [e.g. a driver&#39;s license]; creating and completing a credential template; attaching the photograph to the template; and submitting a new e-credential request to the issuer&#39;s personal identity device. Upon successful proofing of the physical credential and the attached photograph, the issuer creates a new e-credential and attaches the photograph to the new e-credential by way of the user&#39;s personal identity device. Finally, the issuer selects an embossing key to digitally seal both the new credential and the attached photograph, remitting this “certified true copy e-credential” to the user. 
     Certified True Translation Credentials: The above true copy example stimulated the idea of creating additional types of true copy variants by means of the forward-facing camera including true copy translations of birth certificates written in other languages. 
     Certified True Copy Photographs: The above examples stimulated additional refinements. In the first case the user takes a digital self-portrait using the front-facing camera; attaches the photograph to the new credential request; and the issuer returns a digitally sealed certified true copy credential with the attached photograph also digitally sealed. The second case involves a photograph being taken by the issuer&#39;s forward-facing camera and returning the sealed credential and sealed photograph. 
     Identity Proofing with Multi-Media Conferencing: The potential application of multi-media conferencing, using cameras and audio, was not anticipated until the identity assurance implications of in-person and known-person identity proofing became fully appreciated:
         a) For in-person identity proofing, the person requesting an e-credential person need not be known to the e-credential issuer. However, personal identifying information, including at least one physical credential (e.g. a driver&#39;s license), should be required;   b) For known-person identity proofing where the requester and issuer have known each other personally for a prescribed period of time (e.g. 2 or more years), personal identifying information may not be deemed to be necessary;   c) Under both in-person and known-person identity proofing scenarios, depending on the level of perceived risk, it may be advisable for the collaborating users to establish a mutually trusted channel between their personal identity devices.   d) When e-credentialing over an online application (like video conferencing), depending on the perceived risk, it may be acceptable for collaborating users to exchange a one-time secret over an alternate channel, and use that secret to create a shared symmetric encryption key to establish the mutually trusted channel.       

     Persons skilled in the art will recognize that many modifications and variations are possible in the details, materials, and arrangements of the parts and actions which have been described and illustrated in order to explain the nature of this inventive concept and that such modifications and variations do not depart from the spirit and scope of the teachings and claims contained therein. 
     All patent and non-patent literature cited herein is hereby incorporated by references in its entirety for all purposes.