Abstract: A technique, comprising: identifying, at a node forming part of a group of nodes operating a distributed ledger comprising a block chain, a decision to retrospectively change a first smart contract prescribing one or more changes in the ledger already recorded in one or more existing blocks of the blockchain; and, without changing any existing blocks of the blockchain, updating the ledger by adding to the current end of the blockchain a new block indicating a new state of the ledger determined by a re-execution of all operations, according to the first smart contract and one or more other smart contracts, recorded in one or more blocks of the blockchain after a block recording an operation of the first smart contract, while taking into account the change to the first smart contract.

Abstract: An apparatus comprising a processor and memory including computer program code, the memory and computer program code configured to, with the processor, enable the apparatus at least to: identify a target object, from a plurality of objects, which is within a field of view of a first user based on a determined location and orientation of the first user relative to respective predefined locations of the plurality of objects; and generate a command signal configured to trigger a corresponding action associated with the target object.

Abstract: According to an example aspect, there is provided a method for obtaining profile information by a node of a distributed network. Need for providing profile information for a user by a node of a second local private network is detected. A profile request transaction is provided to a public distributed ledger for obtaining profile information associated with the user. Profile information associated with the user is received from a providing node capable of accessing a first private distributed ledger storing the profile information. At least some of the received user profile information is provided for at least one device connected to the second local private network.

Abstract: A technique, comprising: identifying, at an existing node of a distributed ledger network for operation according to a voting-based consensus algorithm, a new candidate node for the distributed ledger network, wherein said identifying is done based on an existing unique identifier unrelated to the distributed ledger network.

Abstract: According to an example aspect of the present invention, there is provided an apparatus comprising at least one processing core, at least one memory including computer program code, the at least one memory and the computer program code being configured to, with the at least one processing core, cause the apparatus at least to obtain a document, segmented into a first number of segments (510), obtain the first number of outputs of a cryptographic operation, such that for each output, a random value and a document segment are employed to generate an input to the cryptographic operation (520), build a Merkle tree based on the outputs of the cryptographic operation (530), and store a top hash of the Merkle tree in a block chain (540).

Abstract: According to an example aspect of the present invention, there is provided an apparatus comprising a memory configured to store an identifier of the apparatus, at least one processing core configured to obtain, from sensor information, a service identifier and a session identifier, compile a message addressed to a service provider associated with the service identifier, the message comprising the identifier of the apparatus and the session identifier, and cause transmission of the message toward the service provider.

Abstract: According to an example aspect, there is provided a method for obtaining profile information by a node of a distributed network. Need for providing profile information for a user by a node of a second local private network is detected. A profile request transaction is provided to a public distributed ledger for obtaining profile information associated with the user. Profile information associated with the user is received from a providing node capable of accessing a first private distributed ledger storing the profile information. At least some of the received user profile information is provided for at least one device connected to the second local private network.

Abstract: An apparatus comprising a processor and memory including computer program code, the memory and computer program code configured to, with the processor, enable the apparatus at least to: identify a target object, from a plurality of objects, which is within a field of view of a first user based on a determined location and orientation of the first user relative to respective predefined locations of the plurality of objects; and generate a command signal configured to trigger a corresponding action associated with the target object.

Abstract: A technique, comprising: identifying, at a node forming part of a group of nodes operating a distributed ledger comprising a block chain, a decision to retrospectively change a first smart contract prescribing one or more changes in the ledger already recorded in one or more existing blocks of the blockchain; and, without changing any existing blocks of the blockchain, updating the ledger by adding to the current end of the blockchain a new block indicating a new state of the ledger determined by a re-execution of all operations, according to the first smart contract and one or more other smart contracts, recorded in one or more blocks of the blockchain after a block recording an operation of the first smart contract, while taking into account the change to the first smart contract.

Abstract: An apparatus configured to, based on: a received daily target activity level for a user; and a received user daily activity profile for the user, the user daily activity profile comprising activity features each comprising specific intensity and specific duration at intervals throughout at least a portion of a day to cumulatively provide a particular activity level for the day, the user daily activity profile based on one or more of: at least one previous user daily activity profile of the user; and at least one previous user daily activity profile of one or more comparable users; generate an adjusted user daily activity profile comprising adjusted activity features each comprising one or more of adjusted specific intensity and adjusted specific duration at intervals throughout at least a portion of a day to cumulatively provide the daily target activity level for the user; and output the adjusted user daily activity profile for use by the user.

Abstract: A technique, comprising: identifying, at an existing node of a distributed ledger network for operation according to a voting-based consensus algorithm, a new candidate node for the distributed ledger network, wherein said identifying is done based on an existing unique identifier unrelated to the distributed ledger network.

Abstract: According to an example aspect of the present invention, there is provided an apparatus comprising at least one processing core, at least one memory including computer program code, the at least one memory and the computer program code being configured to, with the at least one processing core, cause the apparatus at least to obtain a document, segmented into a first number of segments (510), obtain the first number of outputs of a cryptographic operation, such that for each output, a random value and a document segment are employed to generate an input to the cryptographic operation (520), build a Merkle tree based on the outputs of the cryptographic operation (530), and store a top hash of the Merkle tree in a block chain (540).

Abstract: According to an example aspect of the present invention, there is provided an apparatus comprising a memory configured to store an identifier of the apparatus, at least one processing core configured to obtain, from sensor information, a service identifier and a session identifier, compile a message addressed to a service provider associated with the service identifier, the message comprising the identifier of the apparatus and the session identifier, and cause transmission of the message toward the service provider.