Abstract: A method for maintaining state and event information for all of a user's devices associated in a common location using a blockchain where each block includes an event block and a device block within it, where each event and device block refers to an earlier block of the respective type, resulting in a blockchain-in-a-blockchain architecture. The device and event blocks store data regarding each device associated with a user and events related to the devices/user, respectively. Any time a new event occurs, or a device is registered or removed, a new set of blocks is created, where submissions regarding device changes or events can be made by any participant due to the decentralized and public nature of a blockchain. The result is a system where all data regarding a user's registered devices and events is kept in a common location in a manner that is auditable and verifiable.

Abstract: A method for maintaining state and event information for all of a user's devices associated in a common location using a blockchain where each block includes an event block and a device block within it, where each event and device block refers to an earlier block of the respective type, resulting in a blockchain-in-a-blockchain architecture. The device and event blocks store data regarding each device associated with a user and events related to the devices/user, respectively. Any time a new event occurs, or a device is registered or removed, a new set of blocks is created, where submissions regarding device changes or events can be made by any participant due to the decentralized and public nature of a blockchain. The result is a system where all data regarding a user's registered devices and events is kept in a common location in a manner that is auditable and verifiable.

Abstract: A method for maintaining state and event information for all of a user's devices associated in a common location using a blockchain where each block includes an event block and a device block within it, where each event and device block refers to an earlier block of the respective type, resulting in a blockchain-in-a-blockchain architecture. The device and event blocks store data regarding each device associated with a user and events related to the devices/user, respectively. Any time a new event occurs, or a device is registered or removed, a new set of blocks is created, where submissions regarding device changes or events can be made by any participant due to the decentralized and public nature of a blockchain. The result is a system where all data regarding a user's registered devices and events is kept in a common location in a manner that is auditable and verifiable.

Abstract: A method for maintaining state and event information for all of a user's devices associated in a common location using a blockchain where each block includes an event block and a device block within it, where each event and device block refers to an earlier block of the respective type, resulting in a blockchain-in-a-blockchain architecture. The device and event blocks store data regarding each device associated with a user and events related to the devices/user, respectively. Any time a new event occurs, or a device is registered or removed, a new set of blocks is created, where submissions regarding device changes or events can be made by any participant due to the decentralized and public nature of a blockchain. The result is a system where all data regarding a user's registered devices and events is kept in a common location in a manner that is auditable and verifiable.

Abstract: Methods, apparatus and systems for permitting a cardholder to select a cardholder verification method (CVM) during a secure transaction. In an embodiment, a consumer mobile device running a mobile payment application receives, from a cardholder, selection of a payment account and an instruction to pay via one of contactless, barcode, SRC or digital secure remote payment (DSRP). The consumer mobile device then transmits a request for a secure transaction to a merchant device, receives a request for payment account data, displays a plurality of cardholder verification methods (CVMs), receives selection of a CVM, and prompts the cardholder to provide cardholder identification data in accordance with the selected CVM.