Abstract: An instant messaging system based on blockchain includes: a central node and at least two domain instant messaging servers. The central node includes a management node and a blockchain node. Information about a user is stored in the blockchain node. The at least two domain instant messaging servers correspond to at least two instant messaging applications, respectively. A method for implementing the instant messaging system is implemented at the central node, and includes performing, in response to a request from the domain instant messaging server, a corresponding operation or providing corresponding information about a user to the domain instant messaging server. The central node establishes a communication connection with a plurality of domain instant messaging servers, such that each domain instant messaging server can send respectively data to the central node to realize a data sharing, and an interaction between different domain instant messaging servers.

Abstract: A method of user data authorization based on blockchain includes: storing, by a first application client, encrypted user data of user data in a blockchain database through a blockchain node, generating authorization information in response to a request of acquiring the user data by a second application client, and notifying the second application client to obtain the authorization information such that the second application client obtains the user data based on the encrypted user data and the authorization information. The encrypted user data is stored in the blockchain database such that the encrypted user data cannot be tampered with and a leak of real user data is prevented. The second application client obtains the user data based on the authorization information and the encrypted user data.

Abstract: A method of user data authorization based on blockchain includes: storing, by a first application client, encrypted user data of user data in a blockchain database through a blockchain node, generating authorization information in response to a request of acquiring the user data by a second application client, and notifying the second application client to obtain the authorization information such that the second application client obtains the user data based on the encrypted user data and the authorization information. The encrypted user data is stored in the blockchain database such that the encrypted user data cannot be tampered with and a leak of real user data is prevented. The second application client obtains the user data based on the authorization information and the encrypted user data.

Abstract: An instant messaging system based on blockchain includes: a central node and at least two domain instant messaging servers. The central node includes a management node and a blockchain node. Information about a user is stored in the blockchain node. The at least two domain instant messaging servers correspond to at least two instant messaging applications, respectively. A method for implementing the instant messaging system is implemented at the central node, and includes performing, in response to a request from the domain instant messaging server, a corresponding operation or providing corresponding information about a user to the domain instant messaging server. The central node establishes a communication connection with a plurality of domain instant messaging servers, such that each domain instant messaging server can send respectively data to the central node to realize a data sharing, and an interaction between different domain instant messaging servers.

Abstract: A WiFi voice communication system incorporates a plurality of access points (AP) interconnected to a WiFi network. A handset for voice communication through the AP is provided with two sets of medium access control (MAC) components, each of said MAC having the capability to set up a voice or data call with an AP individually and simultaneously, and means for transferring a voice call from one AP to another by transferring from one MAC to another.