A data communication system for a local network (108a, 200, 300), the data communication system comprising at least one network node and a plurality of network devices (106a, 106b, 106c, 106d) associated with the at least one network node, comprising: - the at least one network node is configured to provide a network node service to a plurality of clients or bots executing on the plurality of network devices (106a, 106b, 106c, 106d), wherein individual clients or bots of the plurality of clients or bots are communicably and only programmatically coupled around the network node service in a programmatic star configuration to create the local network (108a, 200, 300), further wherein the network node service is configured to validate and authenticate local services provided by the plurality of clients or bots within the local network (108a, 200, 300); - a source client or bot is configured to communicate data together with metadata to one or more destination clients or bots within the local network (108a, 200, 300) in real time or near real time, by relaying the data through the network node service; and - the source client or bot is configured to encrypt information content of the data prior to communicating the data to the one or more destination clients or bots, wherein the source client or bot is configured to employ a key store to encrypt the information content of the data, the key store being associated with a user of the source client or bot, wherein the metadata comprises: - encryption information indicative of a unique identifier of the key store and a key index of a key material to be derived from the key store for subsequent decryption of the encrypted information content of the data, and - group information indicative of the one or more destination clients or bots to which the data is to be communicated, wherein the source client or bot and the one or more destination clients or bots together form a group. - the at least one network node is configured to provide a network node service to a plurality of clients or bots executing on the plurality of network devices (106a, 106b, 106c, 106d), wherein individual clients or bots of the plurality of clients or bots are communicably and only programmatically coupled around the network node service in a programmatic star configuration to create the local network (108a, 200, 300), further wherein the network node service is configured to validate and authenticate local services provided by the plurality of clients or bots within the local network (108a, 200, 300); - a source client or bot is configured to communicate data together with metadata to one or more destination clients or bots within the local network (108a, 200, 300) in real time or near real time, by relaying the data through the network node service; and - the source client or bot is configured to encrypt information content of the data prior to communicating the data to the one or more destination clients or bots, wherein the source client or bot is configured to employ a key store to encrypt the information content of the data, the key store being associated with a user of the source client or bot, wherein the metadata comprises: - encryption information indicative of a unique identifier of the key store and a key index of a key material to be derived from the key store for subsequent decryption of the encrypted information content of the data, and - group information indicative of the one or more destination clients or bots to which the data is to be communicated, wherein the source client or bot and the one or more destination clients or bots together form a group.