Distributed network messenger system with SPAM filtering, encryption, digital signing and digital contract generation

摘要

Disclosed is a system for message (e.g. email) delivery across a peer-to-peer network. The system has the property of non-repudiation, to prevent spam. The messages are also encrypted to provide confidentiality, and may remain in encrypted form when stored in buffers during transit. An initial step in the security procedure requires the user to enter a non-public ID, which is used to generate a public-private key pair. The user also has a public ID which is equivalent to an e-mail address in conventional systems. When a user wishes to communicate with another node a handshake procedure may be carried out. This involves sending a signed message to the other node, and can be regarded as a form of SPAM filtering. Also disclosed is a system for signing digital contracts to subject subsequent "conversations" to the terms of the contract. According to another aspect of the invention a user is only granted a public ID if he/she has a sufficient trust ranking.