Abstract: A computer-implemented method for managing cryptocurrency is disclosed. A plurality of users are provided with an in-marketplace wallet suitable for storing linked digital tokens that are linked in value to cryptocurrency tokens and are required to transact on a digital marketplace platform. A cryptocurrency reserve is provided for storing cryptocurrency tokens. Responsive to a user purchasing linked digital tokens from a marketplace store, linked digital tokens are transferred to the in-marketplace wallet an equivalent value of cryptocurrency tokens are transferred to the cryptocurrency reserve. Responsive to a user withdrawing a number of linked digital tokens from the in-marketplace wallet, the desired number of linked digital tokens are removed from the user's in-marketplace wallet and an equivalent value of cryptocurrency tokens are transferred from the cryptocurrency reserve to an out-of-marketplace wallet of the user for storing cryptocurrency tokens outside of the marketplace platform.

Abstract: A method and system of providing verification of information of a user relating to an attestation transaction is provided, and includes sending a request for information of the user, wherein the information has been previously attested to in an attestation transaction stored within a centralized or distributed ledger at an attestation address; receiving at a processor associated with a verifier the information of the user; sending a cryptographic challenge nonce; receiving at the processor associated with the verifier the cryptographic challenge nonce signed by the user's private key; verifying user identity with the cryptographic challenge nonce signed by the user's private key; deriving a public attest key by using the information of the user; deriving an attestation address using the public attest key; and verifying the existence of the attestation transaction at the attestation address in the centralized or distributed ledger.

Abstract: A method and system of providing verification of information of a user relating to an attestation transaction is provided, and includes sending a request for information of the user, wherein the information has been previously attested to in an attestation transaction stored within a centralized or distributed ledger at an attestation address; receiving at a processor associated with a verifier the information of the user; sending a cryptographic challenge nonce; receiving at the processor associated with the verifier the cryptographic challenge nonce signed by the user's private key; verifying user identity with the cryptographic challenge nonce signed by the user's private key; deriving a public attest key by using the information of the user; deriving an attestation address using the public attest key; and verifying the existence of the attestation transaction at the attestation address in the centralized or distributed ledger.

Abstract: A computer-implemented method for managing cryptocurrency is disclosed. A plurality of users are provided with an in-marketplace wallet suitable for storing linked digital tokens that are linked in value to cryptocurrency tokens and are required to transact on a digital marketplace platform. A cryptocurrency reserve is provided for storing cryptocurrency tokens. Responsive to a user purchasing linked digital tokens from a marketplace store, linked digital tokens are transferred to the in-marketplace wallet an equivalent value of cryptocurrency tokens are transferred to the cryptocurrency reserve. Responsive to a user withdrawing a number of linked digital tokens from the in-marketplace wallet, the desired number of linked digital tokens are removed from the user's in-marketplace wallet and an equivalent value of cryptocurrency tokens are transferred from the cryptocurrency reserve to an out-of-marketplace wallet of the user for storing cryptocurrency tokens outside of the marketplace platform.

Abstract: A method and system of providing verification of information of a user relating to an attestation transaction is provided, and includes sending a request for information of the user, wherein the information has been previously attested to in an attestation transaction stored within a centralized or distributed ledger at an attestation address; receiving at a processor associated with a verifier the information of the user; sending a cryptographic challenge nonce; receiving at the processor associated with the verifier the cryptographic challenge nonce signed by the user's private key; verifying user identity with the cryptographic challenge nonce signed by the user's private key; deriving a public attest key by using the information of the user; deriving an attestation address using the public attest key; and verifying the existence of the attestation transaction at the attestation address in the centralized or distributed ledger.

Abstract: Providing verification of the identity of a digital entity may include including receiving information and a public key of the digital entity, the information having been previously attested to in an attestation transaction stored within a centralized or distributed ledger at an attestation address, the centralized or distributed ledger providing a record of transactions. The system may derive an attestation address using the information and the public key of the digital entity. The system may verify the existence of the attestation transaction at the attestation address in the centralized or distributed ledger and verify that the attestation transaction has not been revoked. The processor associated with the user may receive a cryptographic challenge nonce signed by the digital entity's private key; and may verify the digital entity's identity with the cryptographic challenge nonce signed by the digital entity's key.

Abstract: Methods and apparatus for providing authentication of information of a user are described. Upon validation of this information, a first hash function is applied to the user's information to create a hash. A public attest key is generated by combining the hash of the user's information with one or more public keys. An attestation address is generated based on the public attest key. A signed transaction which includes the attest key is communicated for storage in a centralized or distributed ledger at the attestation address.

Abstract: Various of the disclosed embodiments generally contemplate computer-implemented systems and methods for selecting an electronic or virtual gift card from among a plurality of possible gift cards or gift card issuers. Various of the embodiments may match and rank the gift cards according to a gift card recipient's characteristics, and possibly to the electronic or virtual gift card itself. Certain embodiments also contemplate the selection of physical gift cards selection, matching, and ranking aspects of the invention. Various methods for operating a gift card business using certain of the embodiments are also disclosed.

Abstract: A method and system of providing verification of information of a user relating to an attestation transaction is provided, and includes sending a request for information of the user, wherein the information has been previously attested to in an attestation transaction stored within a centralized or distributed ledger at an attestation address; receiving at a processor associated with a verifier the information of the user; sending a cryptographic challenge nonce; receiving at the processor associated with the verifier the cryptographic challenge nonce signed by the user's private key; verifying user identity with the cryptographic challenge nonce signed by the user's private key; deriving a public attest key by using the information of the user; deriving an attestation address using the public attest key; and verifying the existence of the attestation transaction at the attestation address in the centralized or distributed ledger.

Abstract: A method and system of providing verification of information of a user relating to an attestation transaction is provided, and includes sending a request for information of the user, wherein the information has been previously attested to in an attestation transaction stored within a centralized or distributed ledger at an attestation address; receiving at a processor associated with a verifier the information of the user; sending a cryptographic challenge nonce; receiving at the processor associated with the verifier the cryptographic challenge nonce signed by the user's private key; verifying user identity with the cryptographic challenge nonce signed by the user's private key; deriving a public attest key by using the information of the user; deriving an attestation address using the public attest key; and verifying the existence of the attestation transaction at the attestation address in the centralized or distributed ledger.

Abstract: Methods and apparatus for providing authentication of information of a user are described. Upon validation of this information, a first hash function is applied to the user's information to create a hash. A public attest key is generated by combining the hash of the user's information with one or more public keys. An attestation address is generated based on the public attest key. A signed transaction which includes the attest key is communicated for storage in a centralized or distributed ledger at the attestation address.

Abstract: Providing verification of the identity of a digital entity may include including receiving information and a public key of the digital entity, the information having been previously attested to in an attestation transaction stored within a centralized or distributed ledger at an attestation address, the centralized or distributed ledger providing a record of transactions. The system may derive an attestation address using the information and the public key of the digital entity. The system may verify the existence of the attestation transaction at the attestation address in the centralized or distributed ledger and verify that the attestation transaction has not been revoked. The processor associated with the user may receive a cryptographic challenge nonce signed by the digital entity's private key; and may verify the digital entity's identity with the cryptographic challenge nonce signed by the digital entity's key.

Abstract: Methods and apparatus for providing authentication of information of a user are described. Upon validation of this information, a first hash function is applied to the user's information to create a hash. A public attest key is generated by combining the hash of the user's information with one or more public keys. An attestation address is generated based on the public attest key. A signed transaction which includes the attest key is communicated for storage in a centralized or distributed ledger at the attestation address.

Abstract: A method and system of providing verification of information of a user relating to an attestation transaction is provided, and includes sending a request for information of the user, wherein the information has been previously attested to in an attestation transaction stored within a centralized or distributed ledger at an attestation address; receiving at a processor associated with a verifier the information of the user; sending a cryptographic challenge nonce; receiving at the processor associated with the verifier the cryptographic challenge nonce signed by the user's private key; verifying user identity with the cryptographic challenge nonce signed by the user's private key; deriving a public attest key by using the information of the user; deriving an attestation address using the public attest key; and verifying the existence of the attestation transaction at the attestation address in the centralized or distributed ledger.

Abstract: A method and system of revoking an attestation transaction regarding information of a user is provided. The method is implemented on a computer system having one or more physical processors configured by machine-readable instructions which, when executed perform the method, including generating a signed revocation transaction to revoke the previously attested information, wherein the information has been previously attested to in an attestation transaction stored within a centralized or distributed ledger at an attestation address, the centralized or distributed ledger providing a verifiable record of transactions; and sending the signed revocation transaction to the centralized or distributed ledger and revoking the attestation transaction by spending cryptocurrency associated with the attestation transaction.

Abstract: Methods and systems of providing verification of the identity of a digital entity are provided, including receiving information and a public key of the digital entity, wherein the information has been previously attested to in an attestation transaction stored within a centralized or distributed ledger at an attestation address, the centralized or distributed ledger providing a record of transactions; deriving an attestation address using the information and the public key of the digital entity; verifying the existence of the attestation transaction at the attestation address in the centralized or distributed ledger and verifying that the attestation transaction has not been revoked; receiving at the processor associated with the user a cryptographic challenge nonce signed by the digital entity's private key; and verifying the digital entity's identity with the cryptographic challenge nonce signed by the digital entity's key.

Abstract: A method and system of revoking an attestation transaction regarding information of a user is provided. The method is implemented on a computer system having one or more physical processors configured by machine-readable instructions which, when executed perform the method, including generating a signed revocation transaction to revoke the previously attested information, wherein the information has been previously attested to in an attestation transaction stored within a centralized or distributed ledger at an attestation address, the centralized or distributed ledger providing a verifiable record of transactions; and sending the signed revocation transaction to the centralized or distributed ledger and revoking the attestation transaction by spending cryptocurrency associated with the attestation transaction.

Abstract: Methods and systems of executing a business transaction from a commercial website are provided, including sending a request for information of the user, wherein the information has been previously attested to in an attestation transaction; receiving the information of the user; sending a cryptographic challenge nonce; receiving the cryptographic challenge nonce signed by the user's private key; verifying user identity with the cryptographic challenge nonce signed by the user's private key; deriving a public attest key by using the information of the user; deriving an attestation address using the public attest key; verifying the existence of the attestation transaction at the attestation address in the centralized or distributed ledger; and upon verification of the existence of the attestation transaction, completing the business transaction.

Abstract: A method and system for executing a business transaction from a merchant is provided, including receiving at a processor associated with the merchant a code representing information of a user, wherein the code is provided by an output device for a processor associated with the user, and wherein the information has been previously attested to in an attestation transaction stored within a centralized or distributed ledger at an attestation address; converting the code to the information of the user; deriving a public attest key by using the information of the user; deriving an attestation address using the public attest key; verifying the existence of the attestation transaction at the attestation address in the centralized or distributed ledger; and upon verification of the existence of the attestation transaction, completing the business transaction.

Abstract: Methods and systems of executing a business transaction from a commercial website are provided, including sending a request for information of the user, wherein the information has been previously attested to in an attestation transaction; receiving the information of the user; sending a cryptographic challenge nonce; receiving the cryptographic challenge nonce signed by the user's private key; verifying user identity with the cryptographic challenge nonce signed by the user's private key; deriving a public attest key by using the information of the user; deriving an attestation address using the public attest key; verifying the existence of the attestation transaction at the attestation address in the centralized or distributed ledger; and upon verification of the existence of the attestation transaction, completing the business transaction.