A method may include splitting an original token into a first sub-token and a second sub-token, generating a first hash value of the first sub-token and a first randomness value, and generating a second hash value of the second sub-token and a second randomness value. The method may also include evaluating an NIZKP regarding the split, and sampling first and second signature keys and verification keys associated with the first and second sub-tokens, respectively. The method may additionally include generating first and second signed values of concatenations of the first and second hash values and the first and second verification keys, respectively, and signed using an initial signature key of a current owner of the original token. The method may additionally include sending the NIZKP, the first and second hash values, the first and second signed values, and the first and second verification keys to the blockchain.

The instant disclosure illustrates how the privacy and security of activities occurring on distributed ledger-based networks (DLNs) can be enhanced with the use of zero-knowledge proofs (ZKPs) that can be used to verify the validity of at least some aspects of the activities without private information related to the activities necessarily being revealed publicly. Methods and systems that are directed at facilitating the tracking and recovery of assets stolen on ZKP-enabled DLNs while preserving the confidentiality of the tokens are presented herein.

Methods, systems, and computer readable medium for verifying interactions with digital components. The method includes receiving input indicating interaction associated with a digital component that is provided by a content provider and presented by a user interface of the user device, determining, by a trusted program of the user device, that the interaction is valid, generating, by the trusted program and based on the determination that the interaction is valid based on a validity evaluation, a digitally signed token that attests the validity of the interaction with the digital component, and providing, by the trusted program and to a third party, the digitally signed token as an indication of the validity of the interaction.

This disclosure relates to data security and cryptography. In one aspect, a method includes updating a user interface of a client device to present user interface controls that enable a user to specify data privacy settings that define how entities collect, store, and use data of the user. The data security system receives a request to modify a data privacy setting for one or more entities from the client device based on user interaction with one or more of the user interface controls. The request includes an ephemeral user identifier for the user and an attestation token. The data security system validates the request using at least the ephemeral user identifier and the attestation token. The data security system transmits data instructing the entity to modify usage of the user data based on the modified given data privacy setting to each of the one or more entities.

A computer-implemented method for maintaining crypto tokens of a first type. A smart contract from a distributed ledger defines a bonding curve being as a sequence of multiple curve segments. A creation or annul function of the smart contract may integrate a bonding curve starting from the current supply size to a new supply size to determine an amount of crypto tokens of a second type. The crypto tokens of the second type may be transferred to or from a pool associated with the smart contract, while crypto tokens of the first type may be transferred to a user or may be destroyed. The current supply size of first type tokens may be updated correspondingly.

A method performed by a user device is disclosed. The method comprising generating a secret and measuring a biometric template of a user operating the user device. The method then generates a plurality of secret shares of the secret and of the biometric template. The user device then transmits the secret shares of the secret and of the biometric template to a plurality of recovery devices. After, the user device may then initiate a recovery of the secret and measure a biometric measurement of the user. Data of the biometric measurement may be transmitted to the plurality of recovery devices, where the recovery devices perform a partial computation. The user device use the plurality of partial computations to determine a match between the biometric template and the biometric measurement. If the two biometrics match, the user device can reconstruct the secret using shares of the secret from the recovery devices.

A method and system are provided for validating a promotional token redeemed at a Point-of-Sale (PoS) terminal, can include receiving, at the Point of Sale (PoS) terminal located at a physical retail location, a promotional token ID from a mobile device associated with a customer. The promotional token ID can be configured to uniquely identify a promotional token to promote a consumer packaged good (CPG) distributed on a social media platform. A CPG is entered at the PoS terminal to determine a CPG ID configured to uniquely identify the CPG. Next, a validation request is generated. The validation request comprises the promotional token ID and the CPG ID. The validation request is then transferred to a server having access to a private blockchain ledger. Upon completion, the PoS terminal will receive, from the server, the redemption status for the promotional token ID based on information stored in the private blockchain ledger responsive to the validation request.

A method may include obtaining, by a first entity, a verification key from a second entity to which an asset is to be transferred. The method may also include proving to an administrator of a blockchain that the first entity is a current owner of the asset, the blockchain hosting a token associated with the asset. The method may additionally include providing an updated randomness value and the token to the second entity. The method may also include sending an updated hash value of the token and the updated randomness, a signed indication of the transfer of the asset from the first entity to the second entity, and the verification key of the second entity to an administrator of the blockchain.

In some examples, in response to a request from a client device for information relating to a transaction stored by a blockchain, a system identifies, using information stored in a distributed storage system that stores data for the blockchain, multiple data owner entities from which permissions are to be obtained for access of the information, and determines an authorization requirement for the information based on a smart contract. The system sends authorization information based on the authorization requirement to trigger a retrieval of authorization tokens from the identified data owner entities for access of the information, and sends the information to the client device in response to receiving the authorization tokens.

An authority transfer system comprising a client, a resource server, a server that receives, from the client, an authorization request requesting permission to access to a resource managed by the resource server, and a user terminal possessed by an owner of the resource is provided. The server registers a first user terminal in accordance with a registration request of the first user terminal being received from the first user terminal, and determines whether or not a registered second user terminal can be deregistered in accordance with a registration cancellation request being received from the first user terminal, and if it is determined that the second user terminal can be deregistered, authenticates the first user terminal or the second user terminal, and deregisters the second user terminal in accordance with the authentication.