Bitmessage

Bitmessage lets you send encrypted messages directly to another person or distribute them to many subscribers. It uses a peer-to-peer communications protocol, allowing messages to move through a decentralized network instead of a central service. This design addresses the privacy concerns that arise when one intermediary handles everyone’s communications.

The system is intended to operate without requiring users to place inherent trust in outside entities, including root certificate authorities. Its authentication method helps recipients identify messages genuinely associated with a sender and recognize attempts to impersonate that sender. Bitmessage also works to hide communication metadata, such as who sent a message and who received it, from passive eavesdroppers while protecting the exchanged content.

Bitmessage suits Windows users who need private person-to-person or subscriber-based communication built around decentralized operation. It is published by Jonathan Warren as freeware in the Security & Privacy category. Version 0.6.1 is the current release for Windows, and its privacy goals cover both message contents and information about the communications themselves.