A diamond asset comprising one or more diamonds and an encryption chip is used to asset-back a cryptographic token that can be used to conduct transactions. The cryptographic token is written to a blockchain using a smart contract that is configured to enable a transaction associated with the token in response to two or more of: a signature by the encryption chip, a signature by the owner of the diamond asset, and a validation of a visual layout of the diamond asset.

The invention provides a secure method for exchanging entities via a blockchain. The invention incorporates tokenisation techniques, and also techniques for embedding metadata in a redeem script of a blockchain transaction. Embodiment(s) provide a method of: generating a first script, the first script comprising: a first set of metadata associated with a first invitation for the exchange of a first entity by a first user, the first set of metadata comprising an indication of the first entity to be offered for exchange and a first location condition for the exchange, a first user public key (P1A) associated with the first user, wherein the first user public key (P1A) is part of an asymmetric cryptographic pair comprising the first user public key (P1A) and a first user private key (V1A). The script may further comprise and a first third-party public key (P1T) associated with a first third-party, wherein the first third-party public key (P1T) is part of an asymmetric cryptographic pair comprising the first third-party public key (P1T) and a first third-party private key (V1T) The method further comprises the steps of hashing the first script to generate a first script hash and publishing the first script and the first script hash on a distributed hash table (DHT).

A proof-of-payment system that allows smart connected devices to confirm a payment information. In one example, a smart connected device that comprises a computing device and program instructions. The program instructions, when executed by the processor, cause the computing device to at least retrieve an encrypted proof-of-payment (PoP) payload from a blockchain and decrypt the encrypted PoP payload to retrieve a first identifier from the encrypted PoP payload. The first identifier from the decrypted PoP payload is matched to a second identifier presented at the smart connected device. An action is triggered in response to the first identifier from the encrypted PoP payload matching the second identifier presented at the smart connected device.

According to at least one embodiment, a method, computer system, and computer program product for model-driven extraction of event data by a computational device is provided. The present invention may include transforming event data of an event occurring on a blockchain network using an event schema to comply with a data model of an external data structure; mapping, based on the event schema and the data model, the event data to a logical structure of the external data structure; and loading the transformed event data to the external data structure to modify a data content of the external data structure based on the mapping.

A method of initiating a transaction in a blockchain system includes receiving, by a processing device, biometric data associated with a first party of a transaction to be added to a block of a blockchain system. The method further includes providing the biometric data to a validation node of the blockchain system. The method further includes determining that the biometric data has been validated by the validation node. The method further includes, in response to determining that the biometric data has been validated, recording, by the processing device, the biometric data in the block of the blockchain system.

Arrangements for controlling access to a protected entity include receiving a redirected client request to access the protected entity that includes a public key of the client; granting, in response to the received redirected request, access tokens of a first type to a client using the public key of the client; identifying a conversion transaction identifying a request to convert the first type of access tokens with access tokens of a second type, the transaction designating the protected entity; determining a conversion value for converting the first-type access tokens into second-type access tokens based on at least one access parameter; converting, using the conversion value, a first sum of the first-type access tokens into a second sum of second-type access tokens; and granting the client access to the protected entity when the sum of second-type of access tokens is received as a payment from the protected entity.

Embodiments are directed to the tracking of data in a generative adversarial network (GAN) model using a distributed ledger system, such as a blockchain. A learning platform implementing a classification model receives, from a third party, a set of data examples generated by a generator model. The set of data examples are processed by the classification model, which outputs a prediction for each data example indicating whether each data example is true or false. The distributed ledger keeps a record of data examples submitted to the learning platform, as well as of predictions determined by the classification model on the learning platform. The learning platform analyzes the records of the distributed ledger, and pairs the records corresponding to the submitted data examples and the generated predictions determined by the classification model, and determines if the predictions were correct. The classification model may then be updated based upon the prediction results.

A blockchain payment channel is effected based on a series of spending transactions exchanged between parties, in which each transaction of the series of spending transactions has a future lock time, before which it cannot be committed to the blockchain, and comprises at least two spendable transaction outputs having respective digital asset values. At computer equipment of the party, a previous transaction of the series of spending transactions is received, and a function is applied to one or more function variables contained in the previous transaction to at least partially determine the current transaction. A portion of the current transaction is cryptographically signed, the signed portion comprising the at least two spendable transaction outputs, using a private key counterpart to the public key of the party, thereby computing a transaction signature for inclusion in the transaction input of the current transaction.

Example embodiments relate to performing activation techniques for contactless cards. For example, embodiments may include performing a near-field communication (NFC) exchange with a contactless card, processing a message comprising data to activate the contactless card, communicating the data to a server to activate the contactless card; and receiving a response from the server, the response to indicate whether the contactless card is successfully activated or not successfully activated.

Provided is a computer-implemented method for securely receiving data via a third-party webpage, including: generating configuration data in response to a request from a first system, the configuration data including a public key of a first key pair; digitally signing the configuration data based on a private key of a second key pair; transmitting the configuration data to the first system, the configuration data including code configured to facilitate the first system to embed a plurality of frames in a webpage, wherein the plurality of frames loads content from a domain that is independent from a domain that hosts the webpage; and verifying the configuration data based on a public key of the second key pair. The computer-implemented method may also include receiving, from a master frame of the plurality of frames, encrypted data. Systems and computer program products are also provided.