An example operation may include one or more of receiving a request associated with a key-value pair stored in a database, determining whether a state of the key-value pair has changed since a most recently received request, and in response to a determination that the state of the key-value pair has changed, generating a data block that includes a changed state of the key-value pair and adding the generated data block to a hash-linked chain of data blocks.

According to an example aspect of the present invention, there is provided a method, comprising: receiving an input ordered set of transactions after a genesis block or a preceding compressed block in a chain of blocks, generating a compressed block on the basis of the input ordered set of transactions, wherein processing of the compressed block results to an equivalent final state as processing of the input ordered set of transactions, and providing the compressed block to a distributed network for establishing a new chain epoch and replacing a set of uncompressed blocks associated with the input ordered set of transactions.

Systems and methods for establishing and fulfilling a smart contract between users and service providers are disclosed. A method includes creating, by one or more nodes in a computer network, a smart contract in response to a request from a user for services and providing the smart contract to a blockchain. The method then includes notifying service providers of the smart contract and receiving responses to the notifications from the service providers. Then the method includes identifying one or more service providers that can complete the service. The method then includes updating the smart contract to include data about the identified service providers. The updated smart contract includes account information for a user account of the user, and account information for service provider accounts of the identified service providers. Then a value interaction is initiated that pushes value from the user account to the service provider accounts.

Secure analytics using homomorphic and injective format-preserving encryption are disclosed herein. An example method includes encoding an analytic parameter set using a homomorphic encryption scheme as a set of homomorphic analytic vectors; transmitting the set of homomorphic analytic vectors to a server system; and receiving a homomorphic encrypted result from the server system, the server system having utilized the homomorphic encryption scheme and a first injective, format-preserving encryption scheme to evaluate the set of homomorphic analytic vectors over a datasource.

Systems and methods for transferring value. A method includes posting, by a user device to a blockchain, a deposit transaction comprising a deposit value and conditions and updating, by the user device, a state according to a transaction amount. The method also includes transmitting, by the user device, a state update of the state to a server computer and responsive to transmitting the state update, and receiving, by the user device, a payment complete message comprising a tuple from the server computer. The method also includes verifying, by the user device, the conditions and processing, by the user device, a server deposit transaction on the blockchain in response to verifying.

A method for facilitating assessment, authorization, and monitoring of policy documents in organizations for cyber security. The method includes a process of receiving indications of policy documents related to an organization from a user, thus, allowing the user to manager cyber security controls of written policy documents in accordance with regulations and standards. The method also includes retrieving regulations from external databases. Further, the method includes analysis of policy documents against regulations and generating insights. Subsequently, the method transmits the generated insights and/or reports to the user. Further, the method includes receiving monitoring data related to the organization from one or more user's PC devices. Further, the method uses a MD5 (Message Digest algorithm 5) hashing function to ensure that a document has not been tampered with and may include a time-based trigger utilizing a standard green/yellow/red light chart for ongoing authorizations and monitoring.

Embodiments of this application provide a hybrid-cloud data storage method and apparatus, a related device, and a cloud system. The data storage method includes: obtaining, by a gateway of a private cloud, to-be-stored data; determining partial data to be encrypted in the to-be-stored data, to obtain first target data; obtaining a first ciphertext obtained after the first target data is encrypted, the first target data being encrypted according to a first key provided by an encryption chip connected to the gateway; generating second target data including the first ciphertext according to the first ciphertext; generating a data slice corresponding to the second target data according to the second target data; and transmitting the data slice corresponding to the second target data to a public cloud for storage.

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.

The present description relates to systems and techniques for allowing a third party verifier to verify aspects of secured data, or successful communication thereof. For example, a message or other data may be associated with a shared manifest that describes aspects of some data but does not reveal or expose the data. As a result, the data may be kept private while selective privacy and verification with respect to the data is achieved by the inclusion of only selected aspects of said data in the shared manifest.

Described herein are systems and methods that allow for secure wireless communication between a contact lens system and an accessory device to protect sensitive data and prevent unauthorized access to confidential information. In certain embodiments, tampering attempts by potential attackers are thwarted by using a Physically Unclonable Functions (PUF) circuit that is immune to reverse engineering. In addition, sensors monitor a to-be-protected electronic device to detect tampering attempts and physical attacks to ensure the physical integrity of the communication system.