Abstract: Decentralised Communication System and Method A decentralised communication system (10) is disclosed. The decentralised communication system includes a proxy system (20) having a single address associated with a plurality recipient systems (40a-40c). The proxy system 20 is configured to provide a received message addressed to the address to each of the plurality of associated recipient systems (40a-40c). A public key data repository (30) stores a static public key (31a-31c) and a plurality of ephemeral public keys (32a1-32an . . . 32c1-32cn) for each of the plurality of recipient systems (40a-40c). A message (50) to a selected one of the recipient systems 40a-40c includes an encrypted marker (51) and an encrypted message body (52). The message body (51) is encrypted using the recipient system's static public key, a selected ephemeral public key of the recipient system, the private key corresponding to the sender's static public key and the private key for a selected one of the sender's ephemeral public keys.