Abstract: Present-day blockchain architectures suffer from several problems, including poor extensibility and scalability. This may stem from tying two parts of the consensus architecture, namely canonicality and validity, too closely together. The Polkadot architecture, which is a heterogeneous multi-chain, provides better extensibility and scalability by setting canonicality and validity apart. Compartmentalizing canonicality and validity and keeping overall functionality to a minimum of security and transport introduces practical core extensibility in situ. Scalability is addressed through a divide-and-conquer approach to canonicality and validity, scaling out of its bonded core through the incentivization of untrusted public nodes. The heterogeneity of this architecture enables many highly divergent types of consensus systems interoperating in a trustless, fully decentralized “federation,” allowing open and closed networks to have trust-free access to each other.

Abstract: Present-day blockchain architectures suffer from several problems, including poor extensibility and scalability. This may stem from tying two parts of the consensus architecture, namely canonicality and validity, too closely together. The Polkadot architecture, which is a heterogeneous multi-chain, provides better extensibility and scalability by setting canonicality and validity apart. Compartmentalizing canonicality and validity and keeping overall functionality to a minimum of security and transport introduces practical core extensibility in situ. Scalability is addressed through a divide-and-conquer approach to canonicality and validity, scaling out of its bonded core through the incentivization of untrusted public nodes. The heterogeneity of this architecture enables many highly divergent types of consensus systems interoperating in a trustless, fully decentralized “federation,” allowing open and closed networks to have trust-free access to each other.

Abstract: Present-day blockchain architectures suffer from several problems, including poor extensibility and scalability. This may stem from tying two parts of the consensus architecture, namely canonicality and validity, too closely together. The Polkadot architecture, which is a heterogeneous multi-chain, provides better extensibility and scalability by setting canonicality and validity apart. Compartmentalizing canonicality and validity and keeping overall functionality to a minimum of security and transport introduces practical core extensibility in situ. Scalability is addressed through a divide-and-conquer approach to canonicality and validity, scaling out of its bonded core through the incentivization of untrusted public nodes. The heterogeneity of this architecture enables many highly divergent types of consensus systems interoperating in a trustless, fully decentralized “federation,” allowing open and closed networks to have trust-free access to each other.

Abstract: Present-day blockchain architectures suffer from several problems, including poor extensibility and scalability. This may stem from tying two parts of the consensus architecture, namely canonicality and validity, too closely together. The Polkadot architecture, which is a heterogeneous multi-chain, provides better extensibility and scalability by setting canonicality and validity apart. Compartmentalizing canonicality and validity and keeping overall functionality to a minimum of security and transport introduces practical core extensibility in situ. Scalability is addressed through a divide-and-conquer approach to canonicality and validity, scaling out of its bonded core through the incentivization of untrusted public nodes. The heterogeneity of this architecture enables many highly divergent types of consensus systems interoperating in a trustless, fully decentralized “federation,” allowing open and closed networks to have trust-free access to each other.

Abstract: Present-day blockchain architectures suffer from several problems, including poor extensibility and scalability. This may stem from tying two parts of the consensus architecture, namely canonicality and validity, too closely together. The Polkadot architecture, which is a heterogeneous multi-chain, provides better extensibility and scalability by setting canonicality and validity apart. Compartmentalizing canonicality and validity and keeping overall functionality to a minimum of security and transport introduces practical core extensibility in situ. Scalability is addressed through a divide-and-conquer approach to canonicality and validity, scaling out of its bonded core through the incentivization of untrusted public nodes. The heterogeneity of this architecture enables many highly divergent types of consensus systems interoperating in a trustless, fully decentralized “federation,” allowing open and closed networks to have trust-free access to each other.

Abstract: The decentralized and distributed architecture of blockchain makes it challenging to store secret data. A Secure Document Access Control System (SEDACS) can store secret data using distributed components without compromising on the distributed security features of the blockchain. SEDACS can include a Secret Store, a blockchain, and a decentralized file system. The blockchain can store rules and permissions for documents that contain the secret data. The Secret Store can generate secret keys that can be used to access the documents. The decentralized file system can store the documents that are encrypted using the secret keys. A user can retrieve the encrypted document provided that the user has the permission to do so. The user can decrypt the encrypted document by decrypting the secret key and using the decrypted secret key to decrypt the document.

Abstract: A device, which may be a peripheral device or a host computing device, comprises a communication interface, a memory and a processor. The processor is arranged to detect imminent disconnection of a communication link between the peripheral device and the host computing device and in response to detecting the imminent disconnection of the communication link, to trigger a data transfer from the host computing device to the peripheral device via the communication interface. The data transfer defines, at least in part, a fixed output data set which, after disconnection, is output via an output device in the peripheral device.

Abstract: Present-day blockchain architectures suffer from several problems, including poor extensibility and scalability. This may stem from tying two parts of the consensus architecture, namely canonicality and validity, too closely together. The Polkadot architecture, which is a heterogeneous multi-chain, provides better extensibility and scalability by setting canonicality and validity apart. Compartmentalizing canonicality and validity and keeping overall functionality to a minimum of security and transport introduces practical core extensibility in situ. Scalability is addressed through a divide-and-conquer approach to canonicality and validity, scaling out of its bonded core through the incentivization of untrusted public nodes. The heterogeneity of this architecture enables many highly divergent types of consensus systems interoperating in a trustless, fully decentralized “federation,” allowing open and closed networks to have trust-free access to each other.

Abstract: A computing device comprises an electronic paper display, a processor and a memory. The memory is arranged to store platform software and application software for at least one application that is not adapted to work with an electronic paper display. The platform software comprises a UI conversion module comprising device-executable instructions, which when executed by the processor, cause the processor to: access a UI element tree for the application; generate a modified UI element tree for the application by removing and/or re-styling at least one UI element; and render data from the application using the modified UI element tree for display on the electronic paper display.

Abstract: A device, which may be a peripheral device or a host computing device, comprises a communication interface, a memory and a processor. The processor is arranged to detect imminent disconnection of a communication link between the peripheral device and the host computing device and in response to detecting the imminent disconnection of the communication link, to trigger a data transfer from the host computing device to the peripheral device via the communication interface. The data transfer defines, at least in part, a fixed output data set which, after disconnection, is output via an output device in the peripheral device.

Abstract: A display device which includes an electronic paper display additionally comprises power harvesting hardware and display update hardware which is configured to control the updating of the electronic paper display based on a sensed power harvesting level which may, in various embodiments, be a current incoming power level as generated by the power harvesting hardware or a stored power level in a power storage device within the display device.

Abstract: A device, which may be a peripheral device or a host computing device, comprises a communication interface, a memory and a processor. The processor is arranged to detect imminent disconnection of a communication link between the peripheral device and the host computing device and in response to detecting the imminent disconnection of the communication link, to trigger a data transfer from the host computing device to the peripheral device via the communication interface. The data transfer defines, at least in part, a fixed output data set which, after disconnection, is output via an output device in the peripheral device.

Abstract: The decentralized and distributed architecture of blockchain makes it challenging to store secret data. A Secure Document Access Control System (SEDACS) can store secret data using distributed components without compromising on the distributed security features of the blockchain. SEDACS can include a Secret Store, a blockchain, and a decentralized file system. The blockchain can store rules and permissions for documents that contain the secret data. The Secret Store can generate secret keys that can be used to access the documents. The decentralized file system can store the documents that are encrypted using the secret keys. A user can retrieve the encrypted document provided that the user has the permission to do so. The user can decrypt the encrypted document by decrypting the secret key and using the decrypted secret key to decrypt the document.

Abstract: Present-day blockchain architectures suffer from several problems, including poor extensibility and scalability. This may stem from tying two parts of the consensus architecture, namely canonicality and validity, too closely together. The Polkadot architecture, which is a heterogeneous multi-chain, provides better extensibility and scalability by setting canonicality and validity apart. Compartmentalizing canonicality and validity and keeping overall functionality to a minimum of security and transport introduces practical core extensibility in situ. Scalability is addressed through a divide-and-conquer approach to canonicality and validity, scaling out of its bonded core through the incentivization of untrusted public nodes. The heterogeneity of this architecture enables many highly divergent types of consensus systems interoperating in a trustless, fully decentralized “federation,” allowing open and closed networks to have trust-free access to each other.

Abstract: A system is described which comprises an input arranged to receive attention tracking data from attention tracking hardware. The attention tracking data, along with parameters associated with each display change request, is then used to select a display change request from a plurality of stored display change requests received from a plurality of different applications and a change defined by the selected display change request is then rendered in a GUI on a display device.

Abstract: A computing device comprises an electronic paper display, a processor and a memory. The memory is arranged to store platform software and application software for at least one application that is not adapted to work with an electronic paper display. The platform software comprises a UI conversion module comprising device-executable instructions, which when executed by the processor, cause the processor to: access a UI element tree for the application; generate a modified UI element tree for the application by removing and/or re-styling at least one UI element; and render data from the application using the modified UI element tree for display on the electronic paper display.

Abstract: A device, which may be a peripheral device or a host computing device, comprises a communication interface, a memory and a processor. The processor is arranged to detect imminent disconnection of a communication link between the peripheral device and the host computing device and in response to detecting the imminent disconnection of the communication link, to trigger a data transfer from the host computing device to the peripheral device via the communication interface. The data transfer defines, at least in part, a fixed output data set which, after disconnection, is output via an output device in the peripheral device.

Abstract: A system is described which comprises an input arranged to receive attention tracking data from attention tracking hardware. The attention tracking data, along with parameters associated with each display change request, is then used to select a display change request from a plurality of stored display change requests received from a plurality of different applications and a change defined by the selected display change request is then rendered in a GUI on a display device.

Abstract: A display device which includes an electronic paper display additionally comprises power harvesting hardware and display update hardware which is configured to control the updating of the electronic paper display based on a sensed power harvesting level which may, in various embodiments, be a current incoming power level as generated by the power harvesting hardware or a stored power level in a power storage device within the display device.

Abstract: A display device has both an emissive display and an electronic paper display. The electronic paper display is used for rendering visually static user input controls and a portion of the emissive display which is close to the electronic paper display is used for rendering visually dynamic user input controls. Also described are covers for an emissive display device, the covers comprising an electronic paper display device, and an emissive display device.